Version: 264.0.3

Also, only read assemblies once from disk

(cherry picked from commit 443a8dfca65be7d60c4bd46181b4c749b4756114)

.editorconfig

@@ -7,6 +7,18 @@ indent_size = 4
 trim_trailing_whitespace = true
 charset = utf-8
 
+max_line_length = 120
+
+# ReSharper properties
+resharper_csharp_max_line_length = 120
+resharper_csharp_wrap_after_declaration_lpar = true
+resharper_csharp_wrap_arguments_style = chop_if_long
+resharper_csharp_wrap_parameters_style = chop_if_long
+resharper_keep_existing_attribute_arrangement = true
+resharper_place_field_attribute_on_same_line = if_owner_is_single_line
+resharper_wrap_chained_binary_patterns = chop_if_long
+resharper_wrap_chained_method_calls = chop_if_long
+
 [*.{csproj,xml,yml,dll.config,targets,props}]
 indent_size = 2
 

.github/workflows/build-docfx.yml

@@ -5,30 +5,30 @@ on:
     - cron: "0 0 * * 0"
 jobs:
   docfx:
-   runs-on: ubuntu-latest
-   steps:
-    - uses: actions/checkout@v3.6.0
-      with:
-        submodules: true
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4.2.2
+        with:
+          submodules: true
 
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3.2.0
-      with:
-        dotnet-version: 8.0.x
+      - name: Setup .NET Core
+        uses: actions/setup-dotnet@v4.1.0
+        with:
+          dotnet-version: 9.0.x
 
-    - name: Install dependencies
-      run: dotnet restore
+      - name: Install dependencies
+        run: dotnet restore
 
-    - name: Build Project
-      run: dotnet build --no-restore /p:WarningsAsErrors=nullable
+      - name: Build Project
+        run: dotnet build --no-restore /p:WarningsAsErrors=nullable
 
-    - name: Build DocFX
-      uses: nikeee/docfx-action@v1.0.0
-      with:
-        args: Robust.Docfx/docfx.json
+      - name: Build DocFX
+        uses: nikeee/docfx-action@v1.0.0
+        with:
+          args: Robust.Docfx/docfx.json
 
-    - name: Publish Docfx Documentation on GitHub Pages
-      uses: maxheld83/ghpages@master
-      env:
-        BUILD_DIR: Robust.Docfx/_robust-site
-        GH_PAT: ${{ secrets.GH_PAT }}
+      - name: Publish Docfx Documentation on GitHub Pages
+        uses: maxheld83/ghpages@master
+        env:
+          BUILD_DIR: Robust.Docfx/_robust-site
+          GH_PAT: ${{ secrets.GH_PAT }}

.github/workflows/build-test.yml

@@ -2,33 +2,32 @@ name: Build & Test
 
 on:
   push:
-    branches: [ master ]
+    branches: [master]
   pull_request:
-    branches: [ master ]
+    branches: [master]
 
 jobs:
   build:
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest ] # , macos-latest] - temporarily disabled due to libfreetype.dll errors.
+        os: [ubuntu-latest, windows-latest] # , macos-latest] - temporarily disabled due to libfreetype.dll errors.
 
     runs-on: ${{ matrix.os }}
 
     steps:
-    - uses: actions/checkout@v3.6.0
-      with:
-        submodules: true
-
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3.2.0
-      with:
-        dotnet-version: 8.0.x
-    - name: Install dependencies
-      run: dotnet restore
-    - name: Build
-      run: dotnet build --no-restore /p:WarningsAsErrors=nullable
-    - name: Robust.UnitTesting
-      run: dotnet test --no-build Robust.UnitTesting/Robust.UnitTesting.csproj -- NUnit.ConsoleOut=0
-    - name: Robust.Analyzers.Tests
-      run: dotnet test --no-build Robust.Analyzers.Tests/Robust.Analyzers.Tests.csproj -- NUnit.ConsoleOut=0
+      - uses: actions/checkout@v4.2.2
+        with:
+          submodules: true
 
+      - name: Setup .NET Core
+        uses: actions/setup-dotnet@v4.1.0
+        with:
+          dotnet-version: 9.0.x
+      - name: Install dependencies
+        run: dotnet restore
+      - name: Build
+        run: dotnet build --no-restore /p:WarningsAsErrors=nullable
+      - name: Robust.UnitTesting
+        run: dotnet test --no-build Robust.UnitTesting/Robust.UnitTesting.csproj -- NUnit.ConsoleOut=0
+      - name: Robust.Analyzers.Tests
+        run: dotnet test --no-build Robust.Analyzers.Tests/Robust.Analyzers.Tests.csproj -- NUnit.ConsoleOut=0

.github/workflows/codeql-analysis.yml

@@ -11,14 +11,8 @@
 #
 name: "CodeQL"
 
-#on:
-#  push:
-#    branches: [ master ]
-#  pull_request:
-#    # The branches below must be a subset of the branches above
-#    branches: [ master ]
-#  schedule:
-#    - cron: '30 18 * * 6'
+on:
+  workflow_dispatch
 
 jobs:
   analyze:
@@ -28,50 +22,50 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        language: [ 'csharp' ]
+        language: ["csharp"]
         # CodeQL supports [ 'cpp', 'csharp', 'go', 'java', 'javascript', 'python' ]
         # Learn more:
         # https://docs.github.com/en/free-pro-team@latest/github/finding-security-vulnerabilities-and-errors-in-your-code/configuring-code-scanning#changing-the-languages-that-are-analyzed
 
     steps:
-    - name: Checkout repository
-      uses: actions/checkout@v3.6.0
-      with:
-        submodules: true
+      - name: Checkout repository
+        uses: actions/checkout@v4.2.2
+        with:
+          submodules: true
 
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3.2.0
-      with:
-        dotnet-version: 7.0.x
+      - name: Setup .NET Core
+        uses: actions/setup-dotnet@v4.1.0
+        with:
+          dotnet-version: 7.0.x
 
-    - name: Build
-      run: dotnet build
+      - name: Build
+        run: dotnet build
 
-    # Initializes the CodeQL tools for scanning.
-    - name: Initialize CodeQL
-      uses: github/codeql-action/init@v1
-      with:
-        languages: ${{ matrix.language }}
-        # If you wish to specify custom queries, you can do so here or in a config file.
-        # By default, queries listed here will override any specified in a config file.
-        # Prefix the list here with "+" to use these queries and those in the config file.
-        # queries: ./path/to/local/query, your-org/your-repo/queries@main
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v1
+        with:
+          languages: ${{ matrix.language }}
+          # If you wish to specify custom queries, you can do so here or in a config file.
+          # By default, queries listed here will override any specified in a config file.
+          # Prefix the list here with "+" to use these queries and those in the config file.
+          # queries: ./path/to/local/query, your-org/your-repo/queries@main
 
-    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
-    # If this step fails, then you should remove it and run the build manually (see below)
-    - name: Autobuild
-      uses: github/codeql-action/autobuild@v1
+      # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+      # If this step fails, then you should remove it and run the build manually (see below)
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v1
 
-    # ℹ️ Command-line programs to run using the OS shell.
-    # 📚 https://git.io/JvXDl
+      # ℹ️ Command-line programs to run using the OS shell.
+      # 📚 https://git.io/JvXDl
 
-    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
-    #    and modify them (or add more) to build your code if your project
-    #    uses a compiled language
+      # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+      #    and modify them (or add more) to build your code if your project
+      #    uses a compiled language
 
-    #- run: |
-    #   make bootstrap
-    #   make release
+      #- run: |
+      #   make bootstrap
+      #   make release
 
-    - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v1
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v1

.github/workflows/publish-client.yml

@@ -3,51 +3,50 @@
 on:
   push:
     tags:
-    - 'v*'
+      - "v*"
 
 jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - name: Parse version
-      id: parse_version
-      shell: pwsh
-      run: |
-        $ver = [regex]::Match($env:GITHUB_REF, "refs/tags/v?(.+)").Groups[1].Value
-        echo ("::set-output name=version::{0}" -f $ver)
+      - name: Parse version
+        id: parse_version
+        shell: pwsh
+        run: |
+          $ver = [regex]::Match($env:GITHUB_REF, "refs/tags/v?(.+)").Groups[1].Value
+          echo ("::set-output name=version::{0}" -f $ver)
 
-    - uses: actions/checkout@v3.6.0
-      with:
-        submodules: true
+      - uses: actions/checkout@v4.2.2
+        with:
+          submodules: true
 
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3.2.0
-      with:
-        dotnet-version: 8.0.x
+      - name: Setup .NET Core
+        uses: actions/setup-dotnet@v4.1.0
+        with:
+          dotnet-version: 9.0.x
 
-    - name: Package client
-      run: Tools/package_client_build.py -p windows mac linux
+      - name: Package client
+        run: Tools/package_client_build.py -p windows mac linux
 
-    - name: Shuffle files around
-      run: |
-        mkdir "release/${{ steps.parse_version.outputs.version }}"
-        mv release/*.zip "release/${{ steps.parse_version.outputs.version }}"
+      - name: Shuffle files around
+        run: |
+          mkdir "release/${{ steps.parse_version.outputs.version }}"
+          mv release/*.zip "release/${{ steps.parse_version.outputs.version }}"
 
-    - name: Upload files to centcomm
-      uses: appleboy/scp-action@master
-      with:
-        host: centcomm.spacestation14.io
-        username: robust-build-push
-        key: ${{ secrets.CENTCOMM_ROBUST_BUILDS_PUSH_KEY }}
-        source: "release/${{ steps.parse_version.outputs.version }}"
-        target: "/var/lib/robust-builds/builds/"
-        strip_components: 1
-
-    - name: Update manifest JSON
-      uses: appleboy/ssh-action@master
-      with:
-        host: centcomm.spacestation14.io
-        username: robust-build-push
-        key: ${{ secrets.CENTCOMM_ROBUST_BUILDS_PUSH_KEY }}
-        script: /home/robust-build-push/push.ps1 ${{ steps.parse_version.outputs.version }}
+      - name: Upload files to Suns
+        uses: appleboy/scp-action@master
+        with:
+          host: suns.spacestation14.com
+          username: robust-build-push
+          key: ${{ secrets.CENTCOMM_ROBUST_BUILDS_PUSH_KEY }}
+          source: "release/${{ steps.parse_version.outputs.version }}"
+          target: "/var/lib/robust-builds/builds/"
+          strip_components: 1
 
+      - name: Update manifest JSON
+        uses: appleboy/ssh-action@master
+        with:
+          host: suns.spacestation14.com
+          username: robust-build-push
+          key: ${{ secrets.CENTCOMM_ROBUST_BUILDS_PUSH_KEY }}
+          script: /home/robust-build-push/push.ps1 ${{ steps.parse_version.outputs.version }}

.github/workflows/test-content.yml

@@ -2,40 +2,39 @@ name: Test content master against engine
 
 on:
   push:
-    branches: [ master ]
+    branches: [master]
   pull_request:
-    branches: [ master ]
+    branches: [master]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
 
     steps:
-    - name: Check out content
-      uses: actions/checkout@v3.6.0
-      with:
-        repository: space-wizards/space-station-14
-        submodules: recursive
+      - name: Check out content
+        uses: actions/checkout@v4.2.2
+        with:
+          repository: space-wizards/space-station-14
+          submodules: recursive
 
-    - name: Setup .NET Core
-      uses: actions/setup-dotnet@v3.2.0
-      with:
-        dotnet-version: 8.0.x
-    - name: Disable submodule autoupdate
-      run: touch BuildChecker/DISABLE_SUBMODULE_AUTOUPDATE
+      - name: Setup .NET Core
+        uses: actions/setup-dotnet@v4.1.0
+        with:
+          dotnet-version: 9.0.x
+      - name: Disable submodule autoupdate
+        run: touch BuildChecker/DISABLE_SUBMODULE_AUTOUPDATE
 
-    - name: Check out engine version
-      run: |
-        cd RobustToolbox
-        git fetch origin ${{ github.sha }}
-        git checkout FETCH_HEAD
-        git submodule update --init --recursive
-    - name: Install dependencies
-      run: dotnet restore
-    - name: Build
-      run: dotnet build --configuration Tools --no-restore
-    - name: Content.Tests
-      run: dotnet test --no-build Content.Tests/Content.Tests.csproj -v n
-    - name: Content.IntegrationTests
-      run: COMPlus_gcServer=1 dotnet test --no-build Content.IntegrationTests/Content.IntegrationTests.csproj -v n
+      - name: Check out engine version
+        run: |
+          cd RobustToolbox
+          git fetch origin ${{ github.sha }}
+          git checkout FETCH_HEAD
+          git submodule update --init --recursive
+      - name: Install dependencies
+        run: dotnet restore
+      - name: Build
+        run: dotnet build --configuration Tools --no-restore
+      - name: Content.Tests
+        run: dotnet test --no-build Content.Tests/Content.Tests.csproj -v n
+      - name: Content.IntegrationTests
+        run: COMPlus_gcServer=1 dotnet test --no-build Content.IntegrationTests/Content.IntegrationTests.csproj -v n

Directory.Packages.props

@@ -1,64 +1,78 @@
 <Project>
+  <PropertyGroup>
+    <!--
+    We actually set ManagePackageVersionsCentrally manually in another import file.
+    Since .NET SDK 8.0.300, ManagePackageVersionsCentrally is automatically set if Directory.Packages.props exists.
+    https://github.com/NuGet/NuGet.Client/pull/5572
+    We actively negate this here, as we have some packages in tree we don't want such automatic behavior for.
+    We use Directory.Build.props to get copy the state *after* our MSBuild config but before Nuget's config.
+    -->
+    <ManagePackageVersionsCentrally />
+  </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="BenchmarkDotNet" Version="0.13.12" />
+    <PackageVersion Include="BenchmarkDotNet" Version="0.14.0" />
     <PackageVersion Include="DiscordRichPresence" Version="1.2.1.24" />
-    <PackageVersion Include="ILReader.Core" Version="1.0.0.4" />
-    <PackageVersion Include="JetBrains.Annotations" Version="2023.3.0" />
-    <PackageVersion Include="JetBrains.Profiler.Api" Version="1.4.0" />
-    <PackageVersion Include="Linguini.Bundle" Version="0.1.3" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzer.Testing" Version="1.1.1"/>
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.NUnit" Version="1.1.1"/>
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Features" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.Common" Version="4.8.0" />
-    <PackageVersion Include="Microsoft.CodeCoverage" Version="17.8.0" />
-    <PackageVersion Include="Microsoft.Data.Sqlite.Core" Version="8.0.0" />
+    <PackageVersion Include="JetBrains.Annotations" Version="2024.3.0" />
+    <PackageVersion Include="JetBrains.Profiler.Api" Version="1.4.8" />
+    <PackageVersion Include="Linguini.Bundle" Version="0.8.1" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzer.Testing" Version="1.1.2" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing" Version="1.1.2" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing" Version="1.1.2" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Features" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.Common" Version="4.12.0" />
+    <PackageVersion Include="Microsoft.CodeCoverage" Version="17.12.0" />
+    <PackageVersion Include="Microsoft.Data.Sqlite.Core" Version="9.0.0" />
     <PackageVersion Include="Microsoft.DotNet.RemoteExecutor" Version="8.0.0-beta.24059.4" />
-    <PackageVersion Include="Microsoft.EntityFrameworkCore.Design" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.Extensions.Logging" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.Extensions.ObjectPool" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.Extensions.Primitives" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.ILVerification" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.0" />
-    <PackageVersion Include="Microsoft.NET.ILLink.Tasks" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageVersion Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.Extensions.Logging" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.Extensions.ObjectPool" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.Extensions.Primitives" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.ILVerification" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.IO.RecyclableMemoryStream" Version="3.0.1" />
+    <PackageVersion Include="Microsoft.NET.ILLink.Tasks" Version="9.0.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageVersion Include="Microsoft.Win32.Registry" Version="5.0.0" />
-    <PackageVersion Include="Moq" Version="4.20.70" />
-    <PackageVersion Include="NUnit" Version="4.0.1" />
-    <PackageVersion Include="NUnit.Analyzers" Version="3.10.0" />
-    <PackageVersion Include="NUnit3TestAdapter" Version="4.5.0" />
+    <PackageVersion Include="Moq" Version="4.20.72" />
+    <PackageVersion Include="NUnit" Version="4.3.2" />
+    <PackageVersion Include="NUnit.Analyzers" Version="4.5.0" />
+    <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
     <PackageVersion Include="Nett" Version="0.15.0" />
-    <PackageVersion Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="6.0.4" />
+    <PackageVersion Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.2" />
     <PackageVersion Include="OpenTK.OpenAL" Version="4.7.7" />
     <PackageVersion Include="OpenToolkit.Graphics" Version="4.0.0-pre9.1" />
-    <PackageVersion Include="Pidgin" Version="3.2.2" />
+    <PackageVersion Include="Pidgin" Version="3.3.0" />
     <PackageVersion Include="Robust.Natives" Version="0.1.1" />
-    <PackageVersion Include="Robust.Natives.Cef" Version="120.1.9" />
+    <PackageVersion Include="Robust.Natives.Cef" Version="131.3.5" />
     <PackageVersion Include="Robust.Shared.AuthLib" Version="0.1.2" />
-    <PackageVersion Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.7" />
-    <PackageVersion Include="SQLitePCLRaw.provider.sqlite3" Version="2.1.7" />
-    <PackageVersion Include="Serilog" Version="3.1.1" />
+    <PackageVersion Include="SQLitePCLRaw.bundle_e_sqlite3" Version="2.1.10" />
+    <PackageVersion Include="SQLitePCLRaw.provider.sqlite3" Version="2.1.10" />
+    <PackageVersion Include="Serilog" Version="4.2.0" />
     <PackageVersion Include="Serilog.Sinks.Loki" Version="4.0.0-beta3" />
     <PackageVersion Include="SharpZstd.Interop" Version="1.5.2-beta2" />
-    <PackageVersion Include="SixLabors.ImageSharp" Version="3.1.3" />
-    <PackageVersion Include="SpaceWizards.HttpListener" Version="0.1.0" />
-    <PackageVersion Include="SpaceWizards.NFluidsynth" Version="0.1.1" />
+    <PackageVersion Include="SixLabors.ImageSharp" Version="3.1.7" />
+    <PackageVersion Include="SpaceWizards.HttpListener" Version="0.1.1" />
+    <PackageVersion Include="SpaceWizards.NFluidsynth" Version="0.2.2" />
     <PackageVersion Include="SpaceWizards.SharpFont" Version="1.0.2" />
     <PackageVersion Include="SpaceWizards.Sodium" Version="0.2.1" />
-    <PackageVersion Include="System.Numerics.Vectors" Version="4.5.0" />
-    <PackageVersion Include="System.Memory" Version="4.5.5" />
-    <PackageVersion Include="System.Runtime.CompilerServices.Unsafe" Version="6.0.0" />
-    <PackageVersion Include="TerraFX.Interop.Windows" Version="10.0.22621.5" />
+    <PackageVersion Include="TerraFX.Interop.Windows" Version="10.0.26100.1" />
     <PackageVersion Include="TerraFX.Interop.Xlib" Version="6.4.0" />
     <PackageVersion Include="VorbisPizza" Version="1.3.0" />
-    <PackageVersion Include="YamlDotNet" Version="13.7.1" />
+    <PackageVersion Include="YamlDotNet" Version="16.3.0" />
     <PackageVersion Include="prometheus-net" Version="8.2.1" />
     <PackageVersion Include="prometheus-net.DotNetRuntime" Version="4.4.0" />
-    <PackageVersion Include="PolySharp" Version="1.14.1" />
+    <PackageVersion Include="PolySharp" Version="1.15.0" />
+
+    <!-- Transitive deps that we need to pin versions for to avoid NuGet warnings. -->
+    <PackageVersion Include="System.Formats.Asn1" Version="9.0.0" />
+    <PackageVersion Include="System.Reflection.Metadata" Version="9.0.0" />
+    <PackageVersion Include="System.Text.Json" Version="9.0.0" />
+    <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="4.12.0" />
   </ItemGroup>
 </Project>

Lidgren.Network/Lidgren.Network.csproj

@@ -12,7 +12,7 @@
     <SkipRobustAnalyzer>true</SkipRobustAnalyzer>
 
     <Nullable>enable</Nullable>
-    <LangVersion>12.0</LangVersion>
+    <LangVersion>13.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>

MSBuild/Robust.Engine.Version.props

@@ -1,4 +1,4 @@
 <Project>
 
-    <!-- This file automatically reset by Tools/version.py -->
+    <!-- This file automatically reset by Tools/version.py -->
 

MSBuild/Robust.Engine.props

@@ -1,8 +1,8 @@
 <Project>
     <!-- Engine-specific properties. Content should not use this file. -->
     <PropertyGroup>
-        <TargetFramework>net8.0</TargetFramework>
-        <LangVersion>12</LangVersion>
+        <TargetFramework>net9.0</TargetFramework>
+        <LangVersion>13</LangVersion>
         <Nullable>enable</Nullable>
         <WarningsAsErrors>nullable</WarningsAsErrors>
     </PropertyGroup>

MSBuild/Robust.Properties.targets

@@ -3,7 +3,7 @@
   <!-- Import this at the end of any project files in Robust and Content. -->
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFramework>net9.0</TargetFramework>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
 

MSBuild/XamlIL.targets

@@ -71,6 +71,6 @@
     </PropertyGroup>
     <Exec
       Condition="'$(_RobustUseExternalMSBuild)' == 'true'"
-      Command="&quot;$(DOTNET_HOST_PATH)&quot; msbuild /nodereuse:false $(MSBuildProjectFile) /t:CompileRobustXaml /p:_RobustForceInternalMSBuild=true /p:Configuration=$(Configuration) /p:RuntimeIdentifier=$(RuntimeIdentifier) /p:TargetFramework=$(TargetFramework) /p:BuildProjectReferences=false"/>
+      Command="&quot;$(DOTNET_HOST_PATH)&quot; msbuild /nodereuse:false $(MSBuildProjectFile) /t:CompileRobustXaml /p:_RobustForceInternalMSBuild=true /p:Configuration=$(Configuration) /p:RuntimeIdentifier=$(RuntimeIdentifier) /p:TargetFramework=$(TargetFramework) /p:BuildProjectReferences=false /p:IntermediateOutputPath=&quot;$(IntermediateOutputPath.TrimEnd('\'))/&quot;"/>
   </Target>
 </Project>

Resources/EnginePrototypes/Audio/audio_entities.yml

@@ -2,4 +2,7 @@
   id: Audio
   name: Audio
   description: Audio entity used by engine
-  save: false
+  save: false
+  components:
+    - type: Transform
+      gridTraversal: false

Resources/EnginePrototypes/Debug/rotation.yml

@@ -1,7 +1,7 @@
 - type: entity
   id: debugRotation
   abstract: true
-  categories: [ debug ]
+  categories: [ Debug ]
   components:
   - type: Sprite
     netsync: false

Resources/EnginePrototypes/Shaders/stockshaders.yml

@@ -4,6 +4,12 @@
   kind: canvas
   light_mode: unshaded
 
+# Simple mix blend
+- type: shader
+  id: Mix
+  kind: canvas
+  blend_mode: Mix
+
 - type: shader
   id: shaded
   kind: canvas

Resources/EnginePrototypes/entityCategory.yml

@@ -1,17 +1,26 @@
 # debug related entities
 - type: entityCategory
-  id: debug
+  id: Debug
   name: entity-category-name-debug
   description: entity-category-desc-debug
+  suffix: entity-category-suffix-debug
 
 # entities that spawn other entities
 - type: entityCategory
-  id: spawner
+  id: Spawner
   name: entity-category-name-spawner
   description: entity-category-desc-spawner
 
-# entities that should be hidden from the spawn menu
+# simple category that just exists to hide prototypes in spawn menus
 - type: entityCategory
-  id: hideSpawnMenu
+  id: HideSpawnMenu
   name: entity-category-name-hide
   description: entity-category-desc-hide
+  hideSpawnMenu: true
+  inheritable: false
+
+# Entity prototypes added by the fork. With CVar you can hide all entities without this category
+- type: entityCategory
+  id: ForkFiltered
+  name: entity-category-name-fork
+  description: entity-category-desc-fork

Resources/Locale/en-US/_engine_lib.ftl

@@ -20,6 +20,26 @@ zzzz-object-pronoun = { GENDER($ent) ->
    *[neuter] it
    }
 
+# Used internally by the DAT-OBJ() function.
+# Not used in en-US. Created to support other languages.
+# (e.g., "to him," "for her")
+zzzz-dat-object = { GENDER($ent) ->
+    [male] him
+    [female] her
+    [epicene] them
+   *[neuter] it
+   }
+
+# Used internally by the GENITIVE() function.
+# Not used in en-US. Created to support other languages.
+# e.g., "у него" (Russian), "seines Vaters" (German).
+zzzz-genitive = { GENDER($ent) ->
+    [male] his
+    [female] her
+    [epicene] their
+   *[neuter] its
+   }
+
 # Used internally by the POSS-PRONOUN() function.
 zzzz-possessive-pronoun = { GENDER($ent) ->
     [male] his

Resources/Locale/en-US/commands.ftl

@@ -1,5 +1,7 @@
 ### Localization for engine console commands
 
+cmd-hint-float = [float]
+
 ## generic command errors
 
 cmd-invalid-arg-number-error = Invalid number of arguments.
@@ -9,7 +11,9 @@ cmd-parse-failure-float = {$arg} is not a valid float.
 cmd-parse-failure-bool = {$arg} is not a valid bool.
 cmd-parse-failure-uid = {$arg} is not a valid entity UID.
 cmd-parse-failure-mapid = {$arg} is not a valid MapId.
+cmd-parse-failure-enum = {$arg} is not a {$enum} Enum.
 cmd-parse-failure-grid = {$arg} is not a valid grid.
+cmd-parse-failure-cultureinfo = "{$arg}" is not valid CultureInfo.
 cmd-parse-failure-entity-exist = UID {$arg} does not correspond to an existing entity.
 cmd-parse-failure-session = There is no session with username: {$username}
 
@@ -43,6 +47,13 @@ cmd-cvar-compl-list = List available CVars
 cmd-cvar-arg-name = <name | ?>
 cmd-cvar-value-hidden = <value hidden>
 
+## 'cvar_subs' command
+cmd-cvar_subs-desc = Lists the OnValueChanged subscriptions for a CVar.
+cmd-cvar_subs-help = Usage: cvar_subs <name>
+
+cmd-cvar_subs-invalid-args = Must provide exactly one argument.
+cmd-cvar_subs-arg-name = <name>
+
 ## 'list' command
 cmd-list-desc = Lists available commands, with optional search filter
 cmd-list-help = Usage: list [filter]
@@ -148,6 +159,7 @@ cmd-savemap-not-exist = Target map does not exist.
 cmd-savemap-init-warning = Attempted to save a post-init map without forcing the save.
 cmd-savemap-attempt = Attempting to save map {$mapId} to {$path}.
 cmd-savemap-success = Map successfully saved.
+cmd-savemap-error = Could not save map! See server log for details.
 cmd-hint-savemap-id = <MapID>
 cmd-hint-savemap-path = <Path>
 cmd-hint-savemap-force = [bool]
@@ -245,9 +257,6 @@ cmd-bind-arg-command = <InputCommand>
 cmd-net-draw-interp-desc = Toggles the debug drawing of the network interpolation.
 cmd-net-draw-interp-help = Usage: net_draw_interp
 
-cmd-net-draw-interp-desc = Toggles the debug drawing of the network interpolation.
-cmd-net-draw-interp-help = Usage: net_draw_interp
-
 cmd-net-watch-ent-desc = Dumps all network updates for an EntityId to the console.
 cmd-net-watch-ent-help = Usage: net_watchent <0|EntityUid>
 
@@ -288,7 +297,7 @@ cmd-lsgrid-desc = Lists grids.
 cmd-lsgrid-help = lsgrid
 
 cmd-addmap-desc = Adds a new empty map to the round. If the mapID already exists, this command does nothing.
-cmd-addmap-help = addmap <mapID> [initialize]
+cmd-addmap-help = addmap <mapID> [pre-init]
 
 cmd-rmmap-desc = Removes a map from the world. You cannot remove nullspace.
 cmd-rmmap-help = rmmap <mapId>
@@ -299,16 +308,9 @@ cmd-savegrid-help = savegrid <gridID> <Path>
 cmd-testbed-desc = Loads a physics testbed on the specified map.
 cmd-testbed-help = testbed <mapid> <test>
 
-cmd-saveconfig-desc = Saves the client configuration to the config file.
-cmd-saveconfig-help = saveconfig
-
 ## 'flushcookies' command
 # Note: the flushcookies command is from Robust.Client.WebView, it's not in the main engine code.
 
-cmd-flushcookies-desc = Flush CEF cookie storage to disk
-cmd-flushcookies-help = This ensure cookies are properly saved to disk in the event of unclean shutdowns.
-    Note that the actual operation is asynchronous.
-
 ## 'addcomp' command
 cmd-addcomp-desc = Adds a component to an entity.
 cmd-addcomp-help = addcomp <uid> <componentName>
@@ -384,9 +386,9 @@ cmd-tp-desc = Teleports a player to any location in the round.
 cmd-tp-help = tp <x> <y> [<mapID>]
 
 cmd-tpto-desc = Teleports the current player or the specified players/entities to the location of the first player/entity.
-cmd-tpto-help = tpto <username|uid> [username|uid]...
-cmd-tpto-destination-hint = destination (uid or username)
-cmd-tpto-victim-hint = entity to teleport (uid or username)
+cmd-tpto-help = tpto <username|uid> [username|NetEntity]...
+cmd-tpto-destination-hint = destination (NetEntity or username)
+cmd-tpto-victim-hint = entity to teleport (NetEntity or username)
 cmd-tpto-parse-error = Cant resolve entity or player: {$str}
 
 cmd-listplayers-desc = Lists all players currently connected.
@@ -429,11 +431,20 @@ cmd-entfo-help = Usage: entfo <entityuid>
     The entity UID can be prefixed with 'c' to convert it to a client entity UID.
 
 cmd-fuck-desc = Throws an exception
-cmd-fuck-help = Throws an exception
+cmd-fuck-help = Usage: fuck
 
-cmd-showpos-desc = Enables debug drawing over all entity positions in the game.
+cmd-showpos-desc = Show the position of all entities on the screen.
 cmd-showpos-help = Usage: showpos
 
+cmd-showrot-desc = Show the rotation of all entities on the screen.
+cmd-showrot-help = Usage: showrot
+
+cmd-showvel-desc = Show the local velocity of all entites on the screen.
+cmd-showvel-help = Usage: showvel
+
+cmd-showangvel-desc = Show the angular velocity of all entities on the screen.
+cmd-showangvel-help = Usage: showangvel
+
 cmd-sggcell-desc = Lists entities on a snap grid cell.
 cmd-sggcell-help = Usage: sggcell <gridID> <vector2i>\nThat vector2i param is in the form x<int>,y<int>.
 
@@ -446,9 +457,6 @@ cmd-showanchored-help = Usage: showanchored
 cmd-dmetamem-desc = Dumps a type's members in a format suitable for the sandbox configuration file.
 cmd-dmetamem-help = Usage: dmetamem <type>
 
-cmd-dmetamem-desc = Displays chunk bounds for the purposes of rendering.
-cmd-dmetamem-help = Usage: showchunkbb <type>
-
 cmd-launchauth-desc = Load authentication tokens from launcher data to aid in testing of live servers.
 cmd-launchauth-help = Usage: launchauth <account name>
 
@@ -515,9 +523,6 @@ cmd-profsnap-help = Usage: profsnap
 cmd-devwindow-desc = Dev Window
 cmd-devwindow-help = Usage: devwindow
 
-cmd-devwindow-desc = Open file
-cmd-devwindow-help = Usage: testopenfile
-
 cmd-scene-desc = Immediately changes the UI scene/state.
 cmd-scene-help = Usage: scene <className>
 
@@ -528,14 +533,11 @@ cmd-hwid-desc = Returns the current HWID (HardWare ID).
 cmd-hwid-help = Usage: hwid
 
 cmd-vvread-desc = Retrieve a path's value using VV (View Variables).
-cmd-vvread-desc = Usage: vvread <path>
+cmd-vvread-help = Usage: vvread <path>
 
 cmd-vvwrite-desc = Modify a path's value using VV (View Variables).
 cmd-vvwrite-help = Usage: vvwrite <path>
 
-cmd-vv-desc = Opens View Variables (VV).
-cmd-vv-help = Usage: vv <path|entity ID|guihover>
-
 cmd-vvinvoke-desc = Invoke/Call a path with arguments using VV.
 cmd-vvinvoke-help = Usage: vvinvoke <path> [arguments...]
 
@@ -573,3 +575,8 @@ cmd-pvs-override-info-desc = Prints information about any PVS overrides associat
 cmd-pvs-override-info-empty = Entity {$nuid} has no PVS overrides.
 cmd-pvs-override-info-global = Entity {$nuid} has a global override.
 cmd-pvs-override-info-clients = Entity {$nuid} has a session override for {$clients}.
+
+cmd-localization_set_culture-desc = Set DefaultCulture for the client LocalizationManager
+cmd-localization_set_culture-help = Usage: localization_set_culture <cultureName>
+cmd-localization_set_culture-culture-name = <cultureName>
+cmd-localization_set_culture-changed = Localization changed to { $code } ({ $nativeName } / { $englishName })

Resources/Locale/en-US/custom-controls.ftl

@@ -4,9 +4,21 @@ entity-spawn-window-title = Entity Spawn Panel
 entity-spawn-window-search-bar-placeholder = search
 entity-spawn-window-clear-button = Clear
 entity-spawn-window-replace-button-text = Replace
-entity-spawn-window-erase-button-text = Erase Mode
 entity-spawn-window-override-menu-tooltip = Override placement
 
+## TileSpawnWindow
+
+tile-spawn-window-title = Place Tiles
+tile-spawn-window-mirror-button-text = Mirror Tiles
+
 ## Console
 
 console-line-edit-placeholder = Command Here
+
+## OutputPanel
+
+output-panel-scroll-down-button-text = Scroll Down
+
+## Common Used
+
+window-erase-button-text = Erase Mode

Resources/Locale/en-US/dev-window.ftl

@@ -0,0 +1,10 @@
+## "Textures" dev window tab
+
+dev-window-tab-textures-title = Textures
+dev-window-tab-textures-reload = Reload
+dev-window-tab-textures-filter = Filter
+dev-window-tab-textures-summary = Total (est): { $bytes }
+dev-window-tab-textures-info = Width: { $width } Height: { $height }
+    PixelType: { $pixelType } sRGB: { $srgb }
+    Name: { $name }
+    Est. memory usage: { $bytes }

Resources/Locale/en-US/entity-category.ftl

@@ -1,8 +1,12 @@
 entity-category-name-debug = Debug
 entity-category-desc-debug = Entity prototypes intended for debugging & testing.
+entity-category-suffix-debug = Debug
 
 entity-category-name-spawner = Spawner
 entity-category-desc-spawner = Entity prototypes that spawn other entities.
 
 entity-category-name-hide = Hidden
-entity-category-desc-hide = Entity prototypes that should be hidden from the spawn menu
+entity-category-desc-hide = Entity prototypes that should be hidden from entity spawn menus
+
+entity-category-name-fork = Fork Filtered
+entity-category-desc-fork = Entity prototypes added by the fork. With CVar you can hide all entities without this category

Resources/Locale/en-US/toolshed-commands.ftl

@@ -1,4 +1,8 @@
-command-description-tpto =
+command-help-usage =
+    Usage:
+command-help-invertible =
+    The behaviour of this command can be inverted using the "not" prefix.
+command-description-tpto =
     Teleport the given entities to some target entity.
 command-description-player-list =
     Returns a list of all player sessions.
@@ -19,7 +23,7 @@ command-description-buildinfo =
 command-description-cmd-list =
     Returns a list of all commands, for this side.
 command-description-explain =
-    Explains the given expression, providing command descriptions and signatures.
+    Explains the given expression, providing command descriptions and signatures. This only works for valid expressions, it can't explain commands that it fails to parse.
 command-description-search =
     Searches through the input for the provided value.
 command-description-stopwatch =
@@ -38,8 +42,7 @@ command-description-as =
 command-description-count =
     Counts the amount of entries in it's input, returning an integer.
 command-description-map =
-    Maps the input over the given block, with the provided expected return type.
-    This command may be modified to not need an explicit return type in the future.
+    Maps the input over the given block.
 command-description-select =
     Selects N objects or N% of objects from the input.
     One can additionally invert this command with not to make it select everything except N objects instead.
@@ -53,10 +56,8 @@ command-description-entities =
     Returns all entities on the server.
 command-description-paused =
     Filters the input entities by whether or not they are paused.
-    This command can be inverted with not.
 command-description-with =
     Filters the input entities by whether or not they have the given component.
-    This command can be inverted with not.
 command-description-fuck =
     Throws an exception.
 command-description-ecscomp-listty =
@@ -95,6 +96,8 @@ command-description-vars =
     Provides a list of all variables set in this session.
 command-description-any =
     Returns true if there's any values in the input, otherwise false.
+command-description-contains =
+    Returns whether the input enumerable contains the specified value.
 command-description-ArrowCommand =
     Assigns the input to a variable.
 command-description-isempty =
@@ -119,6 +122,8 @@ command-description-splat =
     "Splats" a block, value, or variable, creating N copies of it in a list.
 command-description-val =
     Casts the given value, block, or variable to the given type. This is mostly a workaround for current limitations of variables.
+command-description-var =
+    Returns the contents of the given variable. This will attempt to automatically infer a variables type. Compound commands that modify a variable may need to use the 'val' command instead.
 command-description-actor-controlled =
     Filters entities by whether or not they're actively controlled.
 command-description-actor-session =
@@ -143,7 +148,7 @@ command-description-max =
     Returns the maximum of two values.
 command-description-BitAndCommand =
     Performs bitwise AND.
-command-description-BitOrCommand =
+command-description-bitor =
     Performs bitwise OR.
 command-description-BitXorCommand =
     Performs bitwise XOR.
@@ -190,6 +195,8 @@ command-description-spawn-at =
     Spawns an entity at the given coordinates.
 command-description-spawn-on =
     Spawns an entity on the given entity, at it's coordinates.
+command-description-spawn-in =
+    Spawns an entity in the given container on the given entity, dropping it at its coordinates if it doesn't fit
 command-description-spawn-attached =
     Spawns an entity attached to the given entity, at (0 0) relative to it.
 command-description-mappos =
@@ -197,11 +204,11 @@ command-description-mappos =
 command-description-pos =
     Returns an entity's coordinates.
 command-description-tp-coords =
-    Teleports the target to the given coordinates.
+    Teleports the given entities to the target coordinates.
 command-description-tp-to =
-    Teleports the target to the given other entity.
+    Teleports the given entities to the target entity.
 command-description-tp-into =
-    Teleports the target "into" the given other entity, attaching it at (0 0) relative to it.
+    Teleports the given entities "into" the target entity, attaching it at (0 0) relative to it.
 command-description-comp-get =
     Gets the given component from the given entity.
 command-description-comp-add =
@@ -219,9 +226,9 @@ command-description-MulVecCommand =
 command-description-DivVecCommand =
     Divides every element in the input by a scalar (single value).
 command-description-rng-to =
-    Returns a number from its input to its argument (i.e. n..m inclusive)
+    Returns a number between the input (inclusive) and the argument (exclusive).
 command-description-rng-from =
-    Returns a number to its input from its argument (i.e. m..n inclusive)
+    Returns a number between the argument (inclusive) and the input (exclusive))
 command-description-rng-prob =
     Returns a boolean based on the input probability/chance (from 0 to 1)
 command-description-sum =
@@ -271,7 +278,7 @@ command-description-ModVecCommand =
     Performs the modulus operation over the input with the given constant right-hand value.
 command-description-BitAndNotCommand =
     Performs bitwise AND-NOT over the input.
-command-description-BitOrNotCommand =
+command-description-bitornot =
     Performs bitwise OR-NOT over the input.
 command-description-BitXnorCommand =
     Performs bitwise XNOR over the input.

Resources/Locale/en-US/userinterface.ftl

@@ -0,0 +1,2 @@
+popup-copy-button = Copy
+popup-title = Alert!

Resources/Locale/pt-BR/commands.ftl

@@ -136,6 +136,7 @@ cmd-savemap-not-exist = O mapa de destino não existe.
 cmd-savemap-init-warning = Tentativa de salvar um mapa pós-inicialização sem forçar o salvamento.
 cmd-savemap-attempt = Tentando salvar o mapa {$mapId} em {$path}.
 cmd-savemap-success = Mapa salvo com sucesso.
+cmd-savemap-error = Não foi possível salvar o mapa! Consulte o log do servidor para obter detalhes.
 cmd-hint-savemap-id = <MapID>
 cmd-hint-savemap-path = <Path>
 cmd-hint-savemap-force = [bool]

Robust.Analyzers.Tests/AccessAnalyzer_Test.cs

@@ -1,12 +1,8 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CSharp.Testing;
 using Microsoft.CodeAnalysis.Testing;
-using Microsoft.CodeAnalysis.Testing.Verifiers;
 using NUnit.Framework;
-using Robust.Analyzers;
-
-using VerifyCS = Microsoft.CodeAnalysis.CSharp.Testing.NUnit.AnalyzerVerifier<Robust.Analyzers.AccessAnalyzer>;
-using static Microsoft.CodeAnalysis.Testing.DiagnosticResult;
+using VerifyCS = Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.AccessAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
 
 namespace Robust.Analyzers.Tests;
 
@@ -16,7 +12,7 @@ public sealed class AccessAnalyzer_Test
 {
     public Task Verifier(string code, params DiagnosticResult[] expected)
     {
-        var test = new CSharpAnalyzerTest<AccessAnalyzer, NUnitVerifier>()
+        var test = new CSharpAnalyzerTest<AccessAnalyzer, DefaultVerifier>()
         {
             TestState =
             {

Robust.Analyzers.Tests/ByRefEventAnalyzerTest.cs

@@ -0,0 +1,114 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.ByRefEventAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture, TestOf(typeof(ByRefEventAnalyzer))]
+public sealed class ByRefEventAnalyzerTest
+{
+    private const string EventBusDef = """
+        namespace Robust.Shared.GameObjects;
+
+        public readonly struct EntityUid;
+
+        public sealed class EntitySystem
+        {
+            public void RaiseLocalEvent<TEvent>(EntityUid uid, ref TEvent args, bool broadcast = false)
+                where TEvent : notnull { }
+
+            public void RaiseLocalEvent<TEvent>(EntityUid uid, TEvent args, bool broadcast = false)
+                where TEvent : notnull { }
+        }
+
+        public sealed class EntityEventBus
+        {
+            public void RaiseLocalEvent<TEvent>(EntityUid uid, ref TEvent args, bool broadcast = false)
+                where TEvent : notnull { }
+
+            public void RaiseLocalEvent<TEvent>(EntityUid uid, TEvent args, bool broadcast = false)
+                where TEvent : notnull { }
+        }
+        """;
+
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<ByRefEventAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.GameObjects.EventBusAttributes.cs"
+        );
+
+        test.TestState.Sources.Add(("EntityEventBus.cs", EventBusDef));
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task TestSuccess()
+    {
+        const string code = """
+            using Robust.Shared.GameObjects;
+
+            [ByRefEvent]
+            public readonly struct RefEvent;
+            public readonly struct ValueEvent;
+
+            public static class Foo
+            {
+                public static void Bar(EntityEventBus bus)
+                {
+                    bus.RaiseLocalEvent(default(EntityUid), new ValueEvent());
+                    var refEv = new RefEvent();
+                    bus.RaiseLocalEvent(default(EntityUid), ref refEv);
+                }
+            }
+            """;
+
+        await Verifier(code);
+    }
+
+    [Test]
+    public async Task TestWrong()
+    {
+        const string code = """
+            using Robust.Shared.GameObjects;
+
+            [ByRefEvent]
+            public readonly struct RefEvent;
+            public readonly struct ValueEvent;
+
+            public static class Foo
+            {
+                public static void Bar(EntityEventBus bus)
+                {
+                    bus.RaiseLocalEvent(default(EntityUid), new RefEvent());
+                    var valueEv = new ValueEvent();
+                    bus.RaiseLocalEvent(default(EntityUid), ref valueEv);
+                }
+            }
+            """;
+
+        await Verifier(
+            code,
+            // /0/Test0.cs(11,49): error RA0015: Tried to raise a by-ref event 'RefEvent' by value
+            VerifyCS.Diagnostic(ByRefEventAnalyzer.ByRefEventRaisedByValueRule).WithSpan(11, 49, 11, 63).WithArguments("RefEvent"),
+            // /0/Test0.cs(13,49): error RA0016: Tried to raise a value event 'ValueEvent' by-ref
+            VerifyCS.Diagnostic(ByRefEventAnalyzer.ByValueEventRaisedByRefRule).WithSpan(13, 49, 13, 60).WithArguments("ValueEvent")
+        );
+    }
+}

Robust.Analyzers.Tests/ComponentPauseGeneratorTest.cs

@@ -66,6 +66,7 @@ public sealed class ComponentPauseGeneratorTest
             public partial class FooComponent
             {
             [RobustAutoGenerated]
+            [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
             public sealed class FooComponent_AutoPauseSystem : EntitySystem
             {
                 public override void Initialize()
@@ -106,6 +107,7 @@ public sealed class ComponentPauseGeneratorTest
             public partial class FooComponent
             {
             [RobustAutoGenerated]
+            [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
             public sealed class FooComponent_AutoPauseSystem : EntitySystem
             {
                 public override void Initialize()
@@ -147,6 +149,7 @@ public sealed class ComponentPauseGeneratorTest
             public partial class FooComponent
             {
             [RobustAutoGenerated]
+            [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
             public sealed class FooComponent_AutoPauseSystem : EntitySystem
             {
                 public override void Initialize()
@@ -188,6 +191,7 @@ public sealed class ComponentPauseGeneratorTest
             public partial class FooComponent
             {
             [RobustAutoGenerated]
+            [global::System.ComponentModel.EditorBrowsable(global::System.ComponentModel.EditorBrowsableState.Never)]
             public sealed class FooComponent_AutoPauseSystem : EntitySystem
             {
                 public override void Initialize()

Robust.Analyzers.Tests/DataDefinitionAnalyzerTest.cs

@@ -0,0 +1,229 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.DataDefinitionAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class DataDefinitionAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<DataDefinitionAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        test.TestState.Sources.Add(("TestTypeDefs.cs", TestTypeDefs));
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    private const string TestTypeDefs = """
+        using System;
+
+        namespace Robust.Shared.ViewVariables
+        {
+            public sealed class ViewVariablesAttribute : Attribute
+            {
+                public readonly VVAccess Access = VVAccess.ReadOnly;
+
+                public ViewVariablesAttribute() { }
+
+                public ViewVariablesAttribute(VVAccess access)
+                {
+                    Access = access;
+                }
+            }
+            public enum VVAccess : byte
+            {
+                ReadOnly = 0,
+                ReadWrite = 1,
+            }
+        }
+
+        namespace Robust.Shared.Serialization.Manager.Attributes
+        {
+            public class DataFieldBaseAttribute : Attribute;
+            public class DataFieldAttribute(string? tag = null) : DataFieldBaseAttribute;
+            public sealed class DataDefinitionAttribute : Attribute;
+            public sealed class NotYamlSerializableAttribute : Attribute;
+        }
+    """;
+
+    [Test]
+    public async Task NoVVReadOnlyTest()
+    {
+        const string code = """
+            using Robust.Shared.ViewVariables;
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            [DataDefinition]
+            public sealed partial class Foo
+            {
+                [DataField, ViewVariables(VVAccess.ReadWrite)]
+                public int Bad;
+
+                [DataField]
+                public int Good;
+
+                [DataField, ViewVariables]
+                public int Good2;
+
+                [DataField, ViewVariables(VVAccess.ReadOnly)]
+                public int Good3;
+
+                [ViewVariables]
+                public int Good4;
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(7,17): info RA0028: Data field Bad in data definition Foo has ViewVariables attribute with ReadWrite access, which is redundant
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataFieldNoVVReadWriteRule).WithSpan(7, 17, 7, 50).WithArguments("Bad", "Foo")
+        );
+    }
+
+    [Test]
+    public async Task ReadOnlyFieldTest()
+    {
+        const string code = """
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            [DataDefinition]
+            public sealed partial class Foo
+            {
+                [DataField]
+                public readonly int Bad;
+
+                [DataField]
+                public int Good;
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(7,12): error RA0019: Data field Bad in data definition Foo is readonly
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataFieldWritableRule).WithSpan(7, 12, 7, 20).WithArguments("Bad", "Foo")
+        );
+    }
+
+    [Test]
+    public async Task PartialDataDefinitionTest()
+    {
+        const string code = """
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            [DataDefinition]
+            public sealed class Foo { }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(4,15): error RA0017: Type Foo is a DataDefinition but is not partial
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataDefinitionPartialRule).WithSpan(4, 15, 4, 20).WithArguments("Foo")
+        );
+    }
+
+    [Test]
+    public async Task NestedPartialDataDefinitionTest()
+    {
+        const string code = """
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            public sealed class Foo
+            {
+                [DataDefinition]
+                public sealed partial class Nested { }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(3,15): error RA0018: Type Foo contains nested data definition Nested but is not partial
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.NestedDataDefinitionPartialRule).WithSpan(3, 15, 3, 20).WithArguments("Foo", "Nested")
+        );
+    }
+
+    [Test]
+    public async Task RedundantDataFieldTagTest()
+    {
+        const string code = """
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            [DataDefinition]
+            public sealed partial class Foo
+            {
+                [DataField("someValue")]
+                public int SomeValue;
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(6,6): info RA0027: Data field SomeValue in data definition Foo has an explicitly set tag that matches autogenerated tag
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataFieldRedundantTagRule).WithSpan(6, 6, 6, 28).WithArguments("SomeValue", "Foo")
+        );
+    }
+
+    [Test]
+    public async Task ReadOnlyPropertyTest()
+    {
+        const string code = """
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            [DataDefinition]
+            public sealed partial class Foo
+            {
+                [DataField]
+                public int Bad { get; }
+
+                [DataField]
+                public int Good { get; private set; }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(7,20): error RA0020: Data field property Bad in data definition Foo does not have a setter
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataFieldPropertyWritableRule).WithSpan(7, 20, 7, 28).WithArguments("Bad", "Foo")
+        );
+    }
+
+    [Test]
+    public async Task NotYamlSerializableTest()
+    {
+        const string code = """
+            using Robust.Shared.Serialization.Manager.Attributes;
+
+            [NotYamlSerializable]
+            public sealed class NotSerializableClass { }
+
+            [DataDefinition]
+            public sealed partial class Foo
+            {
+                [DataField]
+                public NotSerializableClass BadField;
+
+                [DataField]
+                public NotSerializableClass BadProperty { get; set; }
+
+                public NotSerializableClass GoodField; // Not a DataField, not a problem
+
+                public NotSerializableClass GoodProperty { get; set; } // Not a DataField, not a problem
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(10,12): error RA0033: Data field BadField in data definition Foo is type NotSerializableClass, which is not YAML serializable
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataFieldYamlSerializableRule).WithSpan(10, 12, 10, 32).WithArguments("BadField", "Foo", "NotSerializableClass"),
+            // /0/Test0.cs(13,12): error RA0033: Data field BadProperty in data definition Foo is type NotSerializableClass, which is not YAML serializable
+            VerifyCS.Diagnostic(DataDefinitionAnalyzer.DataFieldYamlSerializableRule).WithSpan(13, 12, 13, 32).WithArguments("BadProperty", "Foo", "NotSerializableClass")
+        );
+    }
+}

Robust.Analyzers.Tests/DependencyAssignAnalyzerTest.cs

@@ -1,10 +1,9 @@
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis.CSharp.Testing;
 using Microsoft.CodeAnalysis.Testing;
-using Microsoft.CodeAnalysis.Testing.Verifiers;
 using NUnit.Framework;
 using VerifyCS =
-    Microsoft.CodeAnalysis.CSharp.Testing.NUnit.AnalyzerVerifier<Robust.Analyzers.DependencyAssignAnalyzer>;
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.DependencyAssignAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
 
 namespace Robust.Analyzers.Tests;
 
@@ -14,7 +13,7 @@ public sealed class DependencyAssignAnalyzerTest
 {
     private static Task Verifier(string code, params DiagnosticResult[] expected)
     {
-        var test = new CSharpAnalyzerTest<DependencyAssignAnalyzer, NUnitVerifier>()
+        var test = new CSharpAnalyzerTest<DependencyAssignAnalyzer, DefaultVerifier>()
         {
             TestState =
             {

Robust.Analyzers.Tests/DuplicateDependencyAnalyzerTest.cs

@@ -0,0 +1,62 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.DuplicateDependencyAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+[TestOf(typeof(DuplicateDependencyAnalyzer))]
+public sealed class DuplicateDependencyAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<DuplicateDependencyAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.IoC.DependencyAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.IoC;
+
+            public sealed class Foo
+            {
+                [Dependency]
+                private object? Field;
+
+                [Dependency]
+                private object? Field2;
+
+                [Dependency]
+                private string? DifferentField;
+
+                private string? NonDependency1;
+                private string? NonDependency2;
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(9,21): warning RA0032: Another [Dependency] field of type 'object?' already exists in this type as field 'Field'
+            VerifyCS.Diagnostic().WithSpan(9, 21, 9, 27).WithArguments("object?", "Field"));
+    }
+}

Robust.Analyzers.Tests/ForbidLiteralAnalyzerTest.cs

@@ -0,0 +1,189 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.ForbidLiteralAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class ForbidLiteralAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<ForbidLiteralAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code },
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Analyzers.ForbidLiteralAttribute.cs"
+        );
+
+        test.TestState.Sources.Add(("TestTypeDefs.cs", TestTypeDefs));
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    private const string TestTypeDefs = """
+        using System.Collections.Generic;
+        using Robust.Shared.Analyzers;
+
+        public sealed class TestClass
+        {
+            public static void OneParameterForbidden([ForbidLiteral] string value) { }
+            public static void TwoParametersFirstForbidden([ForbidLiteral] string first, string second) { }
+            public static void TwoParametersBothForbidden([ForbidLiteral] string first, [ForbidLiteral] string second) { }
+            public static void ListParameterForbidden([ForbidLiteral] List<string> values) { }
+            public static void ParamsListParameterForbidden([ForbidLiteral] params List<string> values) { }
+        }
+
+        public record struct StringWrapper(string value)
+        {
+            private readonly string _value = value;
+
+            public static implicit operator string(StringWrapper wrapper)
+            {
+                return wrapper._value;
+            }
+        }
+    """;
+
+    [Test]
+    public async Task TestOneParameter()
+    {
+        const string code = """
+            public sealed class Tester
+            {
+                private const string _constValue = "foo";
+                private static readonly string StaticValue = "bar";
+                private static readonly StringWrapper WrappedValue = new("biz");
+
+                public void Test()
+                {
+                    TestClass.OneParameterForbidden(_constValue);
+                    TestClass.OneParameterForbidden(StaticValue);
+                    TestClass.OneParameterForbidden(WrappedValue);
+                    TestClass.OneParameterForbidden("baz");
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(12,41): error RA0033: The "value" parameter of OneParameterForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(12, 41, 12, 46).WithArguments("value", "OneParameterForbidden")
+        );
+    }
+
+    [Test]
+    public async Task TestTwoParametersFirstForbidden()
+    {
+        const string code = """
+            public sealed class Tester
+            {
+                private const string _constValue = "foo";
+
+                public void Test()
+                {
+                    TestClass.TwoParametersFirstForbidden(_constValue, "whatever");
+                    TestClass.TwoParametersFirstForbidden(_constValue, _constValue);
+                    TestClass.TwoParametersFirstForbidden("foo", "whatever");
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(9,47): error RA0033: The "first" parameter of TwoParametersFirstForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(9, 47, 9, 52).WithArguments("first", "TwoParametersFirstForbidden")
+        );
+    }
+
+    [Test]
+    public async Task TestTwoParametersBothForbidden()
+    {
+        const string code = """
+            public sealed class Tester
+            {
+                private const string _constValue = "foo";
+                private static readonly string StaticValue = "bar";
+
+                public void Test()
+                {
+                    TestClass.TwoParametersBothForbidden(_constValue, _constValue);
+                    TestClass.TwoParametersBothForbidden(_constValue, StaticValue);
+                    TestClass.TwoParametersBothForbidden(_constValue, "whatever");
+                    TestClass.TwoParametersBothForbidden("whatever", _constValue);
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(10,59): error RA0033: The "second" parameter of TwoParametersBothForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(10, 59, 10, 69).WithArguments("second", "TwoParametersBothForbidden"),
+            // /0/Test0.cs(11,46): error RA0033: The "first" parameter of TwoParametersBothForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(11, 46, 11, 56).WithArguments("first", "TwoParametersBothForbidden")
+        );
+    }
+
+    [Test]
+    public async Task TestListParameter()
+    {
+        const string code = """
+            public sealed class Tester
+            {
+                private const string _constValue = "foo";
+                private static readonly string StaticValue = "bar";
+                private static readonly StringWrapper WrappedValue = new("biz");
+
+                public void Test()
+                {
+                    TestClass.ListParameterForbidden([_constValue, StaticValue, WrappedValue]);
+                    TestClass.ListParameterForbidden(["foo", _constValue, "bar"]);
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(10,43): warning RA0033: The "values" parameter of ListParameterForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(10, 43, 10, 48).WithArguments("values", "ListParameterForbidden"),
+            // /0/Test0.cs(10,63): warning RA0033: The "values" parameter of ListParameterForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(10, 63, 10, 68).WithArguments("values", "ListParameterForbidden")
+        );
+    }
+
+    [Test]
+    public async Task TestParamsListParameter()
+    {
+        const string code = """
+            public sealed class Tester
+            {
+                private const string _constValue = "foo";
+                private static readonly string StaticValue = "bar";
+                private static readonly StringWrapper WrappedValue = new("biz");
+
+                public void Test()
+                {
+                    TestClass.ParamsListParameterForbidden(_constValue, StaticValue, WrappedValue);
+                    TestClass.ParamsListParameterForbidden("foo", _constValue, "bar");
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(10,48): warning RA0033: The "values" parameter of ParamsListParameterForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(10, 48, 10, 53).WithArguments("values", "ParamsListParameterForbidden"),
+            // /0/Test0.cs(10,68): warning RA0033: The "values" parameter of ParamsListParameterForbidden forbids literal values
+            VerifyCS.Diagnostic().WithSpan(10, 68, 10, 73).WithArguments("values", "ParamsListParameterForbidden")
+        );
+    }
+}

Robust.Analyzers.Tests/MustCallBaseAnalyzerTest.cs

@@ -0,0 +1,91 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.MustCallBaseAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class MustCallBaseAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<MustCallBaseAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.IoC.MustCallBaseAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            public class Foo
+            {
+                [MustCallBase]
+                public virtual void Function()
+                {
+
+                }
+
+                [MustCallBase(true)]
+                public virtual void Function2()
+                {
+
+                }
+            }
+
+            public class Bar : Foo
+            {
+                public override void Function()
+                {
+
+                }
+
+                public override void Function2()
+                {
+
+                }
+            }
+
+            public class Baz : Foo
+            {
+                public override void Function()
+                {
+                    base.Function();
+                }
+            }
+
+            public class Bal : Bar
+            {
+                public override void Function2()
+                {
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(20,26): warning RA0028: Overriders of this function must always call the base function
+            VerifyCS.Diagnostic().WithSpan(20, 26, 20, 34),
+            // /0/Test0.cs(41,26): warning RA0028: Overriders of this function must always call the base function
+            VerifyCS.Diagnostic().WithSpan(41, 26, 41, 35));
+    }
+}

Robust.Analyzers.Tests/NoUncachedRegexAnalyzerTest.cs

@@ -0,0 +1,56 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.NoUncachedRegexAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class NoUncachedRegexAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<NoUncachedRegexAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using System.Text.RegularExpressions;
+
+            public static class Foo
+            {
+                public static void Bad()
+                {
+                    Regex.Replace("foo", "bar", "baz");
+                }
+
+                public static void Good()
+                {
+                    var r = new Regex("bar");
+                    r.Replace("foo", "baz");
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(7,9): warning RA0026: Usage of a static Regex function that takes in a pattern string. This can cause constant re-parsing of the pattern.
+            VerifyCS.Diagnostic().WithSpan(7, 9, 7, 43)
+        );
+    }
+}

Robust.Analyzers.Tests/ObsoleteInheritanceAnalyzerTest.cs

@@ -0,0 +1,86 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.ObsoleteInheritanceAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+/// <summary>
+/// Analyzer that implements <c>[ObsoleteInheritance]</c> checking, to give obsoletion warnings for inheriting types
+/// that should never have been virtual.
+/// </summary>
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class ObsoleteInheritanceAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<ObsoleteInheritanceAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code },
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Analyzers.ObsoleteInheritanceAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task TestBasic()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            [ObsoleteInheritance]
+            public class Base;
+
+            public class NotAllowed : Base;
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(6,14): warning RA0034: Type 'NotAllowed' inherits from 'Base', which has obsoleted inheriting from itself
+            VerifyCS.Diagnostic(ObsoleteInheritanceAnalyzer.Rule).WithSpan(6, 14, 6, 24).WithArguments("NotAllowed", "Base")
+            );
+    }
+
+    [Test]
+    public async Task TestMessage()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            [ObsoleteInheritance("Sus")]
+            public class Base;
+
+            public class NotAllowed : Base;
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(6,14): warning RA0034: Type 'NotAllowed' inherits from 'Base', which has obsoleted inheriting from itself: "Sus"
+            VerifyCS.Diagnostic(ObsoleteInheritanceAnalyzer.RuleWithMessage).WithSpan(6, 14, 6, 24).WithArguments("NotAllowed", "Base", "Sus")
+        );
+    }
+
+    [Test]
+    public async Task TestNormal()
+    {
+        const string code = """
+            public class Base;
+
+            public class AllowedAllowed : Base;
+            """;
+
+        await Verifier(code);
+    }
+}

Robust.Analyzers.Tests/PreferNonGenericVariantForTest.cs

@@ -0,0 +1,70 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.PreferNonGenericVariantForAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class PreferNonGenericVariantForTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<PreferNonGenericVariantForAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code },
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Analyzers.PreferNonGenericVariantForAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            public class Bar { };
+            public class Baz { };
+            public class Okay { };
+
+            public static class Foo
+            {
+                [PreferNonGenericVariantFor(typeof(Bar), typeof(Baz))]
+                public static void DoFoo<T>() { }
+            }
+
+            public class Test
+            {
+                public void DoBad()
+                {
+                    Foo.DoFoo<Bar>();
+                }
+
+                public void DoGood()
+                {
+                    Foo.DoFoo<Okay>();
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(17,9): warning RA0029: Use the non-generic variant of this method for type Bar
+            VerifyCS.Diagnostic().WithSpan(17, 9, 17, 25).WithArguments("Bar")
+        );
+    }
+}

Robust.Analyzers.Tests/PreferOtherTypeAnalyzerTest.cs

@@ -0,0 +1,61 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.PreferOtherTypeAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+public sealed class PreferOtherTypeAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpAnalyzerTest<PreferOtherTypeAnalyzer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code },
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Analyzers.PreferOtherTypeAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            public class EntityPrototype { };
+            public class EntProtoId { };
+            public class ReagentPrototype { };
+
+            [PreferOtherType(typeof(EntityPrototype), typeof(EntProtoId))]
+            public class ProtoId<T> { };
+
+            public class Test
+            {
+                public ProtoId<EntityPrototype> Bad = new();
+
+                public ProtoId<ReagentPrototype> Good = new();
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(12,12): warning RA0031: Use the specific type EntProtoId instead of ProtoId when the type argument is EntityPrototype
+            VerifyCS.Diagnostic().WithSpan(12, 12, 12, 48).WithArguments("EntProtoId", "ProtoId", "EntityPrototype")
+        );
+    }
+}

Robust.Analyzers.Tests/PreferOtherTypeFixerTest.cs

@@ -0,0 +1,80 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.PreferOtherTypeAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+public sealed class PreferOtherTypeFixerTest
+{
+    private static Task Verifier(string code, string fixedCode, params DiagnosticResult[] expected)
+    {
+        var test = new CSharpCodeFixTest<PreferOtherTypeAnalyzer, PreferOtherTypeFixer, DefaultVerifier>()
+        {
+            TestState =
+            {
+                Sources = { code },
+            },
+            FixedState =
+            {
+                Sources = { fixedCode },
+            }
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Analyzers.PreferOtherTypeAttribute.cs"
+        );
+
+        TestHelper.AddEmbeddedSources(
+            test.FixedState,
+            "Robust.Shared.Analyzers.PreferOtherTypeAttribute.cs"
+        );
+
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.Analyzers;
+
+            public class EntityPrototype { };
+            public class EntProtoId { };
+            public class ReagentPrototype { };
+
+            [PreferOtherType(typeof(EntityPrototype), typeof(EntProtoId))]
+            public class ProtoId<T> { };
+
+            public class Test
+            {
+                public ProtoId<EntityPrototype> Foo = new();
+            }
+            """;
+
+        const string fixedCode = """
+            using Robust.Shared.Analyzers;
+
+            public class EntityPrototype { };
+            public class EntProtoId { };
+            public class ReagentPrototype { };
+
+            [PreferOtherType(typeof(EntityPrototype), typeof(EntProtoId))]
+            public class ProtoId<T> { };
+
+            public class Test
+            {
+                public EntProtoId Foo = new();
+            }
+            """;
+
+        await Verifier(code, fixedCode,
+        // /0/Test0.cs(12,12): error RA0031: Use the specific type EntProtoId instead of ProtoId when the type argument is EntityPrototype
+        VerifyCS.Diagnostic().WithSpan(12, 12, 12, 48).WithArguments("EntProtoId", "ProtoId", "EntityPrototype"));
+    }
+}

Robust.Analyzers.Tests/PrototypeInstantiationAnalyzerTest.cs

@@ -0,0 +1,64 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.PrototypeInstantiationAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+[TestOf(typeof(PrototypeInstantiationAnalyzer))]
+public sealed class PrototypeInstantiationAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new RTAnalyzerTest<PrototypeInstantiationAnalyzer>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Prototypes.Attributes.cs",
+            "Robust.Shared.Prototypes.IPrototype.cs",
+            "Robust.Shared.Serialization.Manager.Attributes.DataFieldAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using Robust.Shared.Serialization;
+            using Robust.Shared.Prototypes;
+
+            [Prototype]
+            public sealed class FooPrototype : IPrototype
+            {
+                [IdDataField]
+                public string ID { get; private set; } = default!;
+            }
+
+            public static class Bad
+            {
+                public static FooPrototype Real()
+                {
+                    return new FooPrototype();
+                }
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(15,16): warning RA0039: Do not instantiate prototypes directly. Prototypes should always be instantiated by the prototype manager.
+            VerifyCS.Diagnostic().WithSpan(15, 16, 15, 34));
+    }
+}

Robust.Analyzers.Tests/PrototypeNetSerializableAnalyzerTest.cs

@@ -0,0 +1,61 @@
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis.Testing;
+using NUnit.Framework;
+using VerifyCS =
+    Microsoft.CodeAnalysis.CSharp.Testing.CSharpAnalyzerVerifier<Robust.Analyzers.PrototypeNetSerializableAnalyzer, Microsoft.CodeAnalysis.Testing.DefaultVerifier>;
+
+namespace Robust.Analyzers.Tests;
+
+[Parallelizable(ParallelScope.All | ParallelScope.Fixtures)]
+[TestFixture]
+[TestOf(typeof(PrototypeNetSerializableAnalyzer))]
+public sealed class PrototypeNetSerializableAnalyzerTest
+{
+    private static Task Verifier(string code, params DiagnosticResult[] expected)
+    {
+        var test = new RTAnalyzerTest<PrototypeNetSerializableAnalyzer>()
+        {
+            TestState =
+            {
+                Sources = { code }
+            },
+        };
+
+        TestHelper.AddEmbeddedSources(
+            test.TestState,
+            "Robust.Shared.Serialization.NetSerializableAttribute.cs",
+            "Robust.Shared.Prototypes.Attributes.cs",
+            "Robust.Shared.Prototypes.IPrototype.cs",
+            "Robust.Shared.Serialization.Manager.Attributes.DataFieldAttribute.cs"
+        );
+
+        // ExpectedDiagnostics cannot be set, so we need to AddRange here...
+        test.TestState.ExpectedDiagnostics.AddRange(expected);
+
+        return test.RunAsync();
+    }
+
+    [Test]
+    public async Task Test()
+    {
+        const string code = """
+            using System;
+            using Robust.Shared.Serialization;
+            using Robust.Shared.Prototypes;
+
+            [Prototype]
+            [Serializable, NetSerializable]
+            public sealed class FooPrototype : IPrototype
+            {
+                [IdDataField]
+                public string ID { get; private set; } = default!;
+            }
+            """;
+
+        await Verifier(code,
+            // /0/Test0.cs(7,21): warning RA0037: Type FooPrototype is a prototype and marked as [NetSerializable]. Prototypes should not be directly sent over the network, send their IDs instead.
+            VerifyCS.Diagnostic(PrototypeNetSerializableAnalyzer.RuleNetSerializable).WithSpan(7, 21, 7, 33).WithArguments("FooPrototype"),
+            // /0/Test0.cs(7,21): warning RA0038: Type FooPrototype is a prototype and marked as [Serializable]. Prototypes should not be directly sent over the network, send their IDs instead.
+            VerifyCS.Diagnostic(PrototypeNetSerializableAnalyzer.RuleSerializable).WithSpan(7, 21, 7, 33).WithArguments("FooPrototype"));
+    }
+}

Robust.Analyzers.Tests/RTAnalyzerTest.cs

@@ -0,0 +1,17 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Testing;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Testing;
+
+namespace Robust.Analyzers.Tests;
+
+public sealed class RTAnalyzerTest<TAnalyzer> : CSharpAnalyzerTest<TAnalyzer, DefaultVerifier>
+    where TAnalyzer : DiagnosticAnalyzer, new()
+{
+    protected override ParseOptions CreateParseOptions()
+    {
+        var baseOptions = (CSharpParseOptions) base.CreateParseOptions();
+        return baseOptions.WithPreprocessorSymbols("ROBUST_ANALYZERS_TEST");
+    }
+}

Robust.Analyzers.Tests/Robust.Analyzers.Tests.csproj

@@ -10,7 +10,17 @@
   <ItemGroup>
     <EmbeddedResource Include="..\Robust.Shared\Analyzers\AccessAttribute.cs" LogicalName="Robust.Shared.Analyzers.AccessAttribute.cs" LinkBase="Implementations" />
     <EmbeddedResource Include="..\Robust.Shared\Analyzers\AccessPermissions.cs" LogicalName="Robust.Shared.Analyzers.AccessPermissions.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Analyzers\MustCallBaseAttribute.cs" LogicalName="Robust.Shared.IoC.MustCallBaseAttribute.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Analyzers\PreferNonGenericVariantForAttribute.cs" LogicalName="Robust.Shared.Analyzers.PreferNonGenericVariantForAttribute.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Analyzers\PreferOtherTypeAttribute.cs" LogicalName="Robust.Shared.Analyzers.PreferOtherTypeAttribute.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Analyzers\ForbidLiteralAttribute.cs" LogicalName="Robust.Shared.Analyzers.ForbidLiteralAttribute.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Analyzers\ObsoleteInheritanceAttribute.cs" LogicalName="Robust.Shared.Analyzers.ObsoleteInheritanceAttribute.cs" LinkBase="Implementations" />
     <EmbeddedResource Include="..\Robust.Shared\IoC\DependencyAttribute.cs" LogicalName="Robust.Shared.IoC.DependencyAttribute.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\GameObjects\EventBusAttributes.cs" LogicalName="Robust.Shared.GameObjects.EventBusAttributes.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Serialization\NetSerializableAttribute.cs" LogicalName="Robust.Shared.Serialization.NetSerializableAttribute.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Prototypes\Attributes.cs" LogicalName="Robust.Shared.Prototypes.Attributes.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Prototypes\IPrototype.cs" LogicalName="Robust.Shared.Prototypes.IPrototype.cs" LinkBase="Implementations" />
+    <EmbeddedResource Include="..\Robust.Shared\Serialization\Manager\Attributes\DataFieldAttribute.cs" LogicalName="Robust.Shared.Serialization.Manager.Attributes.DataFieldAttribute.cs" LinkBase="Implementations" />
   </ItemGroup>
 
   <PropertyGroup>
@@ -24,12 +34,17 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.CodeAnalysis.Analyzer.Testing"/>
     <PackageReference Include="Microsoft.CodeAnalysis.CSharp"/>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing.NUnit"/>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces"/>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Analyzer.Testing"/>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.CodeFix.Testing"/>
     <PackageReference Include="NUnit"/>
     <PackageReference Include="NUnit3TestAdapter"/>
     <PackageReference Include="NUnit.Analyzers"/>
     <PackageReference Include="Microsoft.NET.Test.Sdk"/>
+
+    <!-- Needed to fix transitive dependency versions -->
+    <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.Common" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" />
+    <PackageReference Include="System.Formats.Asn1" />
   </ItemGroup>
 
   <ItemGroup>

Robust.Analyzers/ByRefEventAnalyzer.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 using System.Collections.Immutable;
 using System.Linq;
 using Microsoft.CodeAnalysis;
@@ -24,7 +24,7 @@ public sealed class ByRefEventAnalyzer : DiagnosticAnalyzer
         "Make sure that methods subscribing to a ref event have the ref keyword for the event argument."
     );
 
-    private static readonly DiagnosticDescriptor ByRefEventRaisedByValueRule = new(
+    public static readonly DiagnosticDescriptor ByRefEventRaisedByValueRule = new(
         Diagnostics.IdByRefEventRaisedByValue,
         "By-ref event raised by value",
         "Tried to raise a by-ref event '{0}' by value",
@@ -34,7 +34,7 @@ public sealed class ByRefEventAnalyzer : DiagnosticAnalyzer
         "Make sure to use the ref keyword when raising ref events."
     );
 
-    private static readonly DiagnosticDescriptor ByValueEventRaisedByRefRule = new(
+    public static readonly DiagnosticDescriptor ByValueEventRaisedByRefRule = new(
         Diagnostics.IdValueEventRaisedByRef,
         "Value event raised by-ref",
         "Tried to raise a value event '{0}' by-ref",
@@ -54,32 +54,44 @@ public sealed class ByRefEventAnalyzer : DiagnosticAnalyzer
     {
         context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.ReportDiagnostics);
         context.EnableConcurrentExecution();
-        context.RegisterOperationAction(CheckEventRaise, OperationKind.Invocation);
+        context.RegisterCompilationStartAction(compilationContext =>
+        {
+            var raiseMethods = compilationContext.Compilation
+                .GetTypeByMetadataName("Robust.Shared.GameObjects.EntitySystem")?
+                .GetMembers()
+                .Where(m => m.Name.Contains("RaiseLocalEvent") && m.Kind == SymbolKind.Method)
+                .Cast<IMethodSymbol>();
+
+            var busRaiseMethods = compilationContext.Compilation
+                .GetTypeByMetadataName("Robust.Shared.GameObjects.EntityEventBus")?
+                .GetMembers()
+                .Where(m => m.Name.Contains("RaiseLocalEvent") && m.Kind == SymbolKind.Method)
+                .Cast<IMethodSymbol>();
+
+            if (raiseMethods == null)
+                return;
+
+            if (busRaiseMethods != null)
+                raiseMethods = raiseMethods.Concat(busRaiseMethods);
+
+            var raiseMethodsArray = raiseMethods.ToArray();
+
+            compilationContext.RegisterOperationAction(
+                ctx => CheckEventRaise(ctx, raiseMethodsArray),
+                OperationKind.Invocation);
+        });
     }
 
-    private void CheckEventRaise(OperationAnalysisContext context)
+    private static void CheckEventRaise(
+        OperationAnalysisContext context,
+        IReadOnlyCollection<IMethodSymbol> raiseMethods)
     {
         if (context.Operation is not IInvocationOperation operation)
             return;
 
-        var raiseMethods = context.Compilation
-            .GetTypeByMetadataName("Robust.Shared.GameObjects.EntitySystem")?
-            .GetMembers()
-            .Where(m => m.Name.Contains("RaiseLocalEvent") && m.Kind == SymbolKind.Method)
-            .Cast<IMethodSymbol>();
-
-        var busRaiseMethods = context.Compilation
-            .GetTypeByMetadataName("Robust.Shared.GameObjects.EntityEventBus")?
-            .GetMembers()
-            .Where(m => m.Name.Contains("RaiseLocalEvent") && m.Kind == SymbolKind.Method)
-            .Cast<IMethodSymbol>();
-
-        if (raiseMethods == null)
+        if (!operation.TargetMethod.Name.Contains("RaiseLocalEvent"))
             return;
 
-        if (busRaiseMethods != null)
-            raiseMethods = raiseMethods.Concat(busRaiseMethods);
-
         if (!raiseMethods.Any(m => m.Equals(operation.TargetMethod.OriginalDefinition, Default)))
         {
             // If you try to do this normally by concatenating like busRaiseMethods above

Robust.Analyzers/DataDefinitionAnalyzer.cs

@@ -6,6 +6,8 @@ using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;
 using Robust.Roslyn.Shared;
+using Robust.Shared.Serialization.Manager.Definition;
+using Robust.Shared.ViewVariables;
 
 namespace Robust.Analyzers;
 
@@ -15,8 +17,12 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
     private const string DataDefinitionNamespace = "Robust.Shared.Serialization.Manager.Attributes.DataDefinitionAttribute";
     private const string ImplicitDataDefinitionNamespace = "Robust.Shared.Serialization.Manager.Attributes.ImplicitDataDefinitionForInheritorsAttribute";
     private const string DataFieldBaseNamespace = "Robust.Shared.Serialization.Manager.Attributes.DataFieldBaseAttribute";
+    private const string ViewVariablesNamespace = "Robust.Shared.ViewVariables.ViewVariablesAttribute";
+    private const string NotYamlSerializableName = "Robust.Shared.Serialization.Manager.Attributes.NotYamlSerializableAttribute";
+    private const string DataFieldAttributeName = "DataField";
+    private const string ViewVariablesAttributeName = "ViewVariables";
 
-    private static readonly DiagnosticDescriptor DataDefinitionPartialRule = new(
+    public static readonly DiagnosticDescriptor DataDefinitionPartialRule = new(
         Diagnostics.IdDataDefinitionPartial,
         "Type must be partial",
         "Type {0} is a DataDefinition but is not partial",
@@ -26,7 +32,7 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         "Make sure to mark any type that is a data definition as partial."
     );
 
-    private static readonly DiagnosticDescriptor NestedDataDefinitionPartialRule = new(
+    public static readonly DiagnosticDescriptor NestedDataDefinitionPartialRule = new(
         Diagnostics.IdNestedDataDefinitionPartial,
         "Type must be partial",
         "Type {0} contains nested data definition {1} but is not partial",
@@ -36,7 +42,7 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         "Make sure to mark any type containing a nested data definition as partial."
     );
 
-    private static readonly DiagnosticDescriptor DataFieldWritableRule = new(
+    public static readonly DiagnosticDescriptor DataFieldWritableRule = new(
         Diagnostics.IdDataFieldWritable,
         "Data field must not be readonly",
         "Data field {0} in data definition {1} is readonly",
@@ -46,7 +52,7 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         "Make sure to remove the readonly modifier."
     );
 
-    private static readonly DiagnosticDescriptor DataFieldPropertyWritableRule = new(
+    public static readonly DiagnosticDescriptor DataFieldPropertyWritableRule = new(
         Diagnostics.IdDataFieldPropertyWritable,
         "Data field property must have a setter",
         "Data field property {0} in data definition {1} does not have a setter",
@@ -56,8 +62,39 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         "Make sure to add a setter."
     );
 
+    public static readonly DiagnosticDescriptor DataFieldRedundantTagRule = new(
+        Diagnostics.IdDataFieldRedundantTag,
+        "Data field has redundant tag specified",
+        "Data field {0} in data definition {1} has an explicitly set tag that matches autogenerated tag",
+        "Usage",
+        DiagnosticSeverity.Info,
+        true,
+        "Make sure to remove the tag string from the data field attribute."
+    );
+
+    public static readonly DiagnosticDescriptor DataFieldNoVVReadWriteRule = new(
+        Diagnostics.IdDataFieldNoVVReadWrite,
+        "Data field has VV ReadWrite",
+        "Data field {0} in data definition {1} has ViewVariables attribute with ReadWrite access, which is redundant",
+        "Usage",
+        DiagnosticSeverity.Info,
+        true,
+        "Make sure to remove the ViewVariables attribute."
+    );
+
+    public static readonly DiagnosticDescriptor DataFieldYamlSerializableRule = new(
+        Diagnostics.IdDataFieldYamlSerializable,
+        "Data field type is not YAML serializable",
+        "Data field {0} in data definition {1} is type {2}, which is not YAML serializable",
+        "Usage",
+        DiagnosticSeverity.Error,
+        true,
+        "Make sure to use a type that is YAML serializable."
+    );
+
     public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(
-        DataDefinitionPartialRule, NestedDataDefinitionPartialRule, DataFieldWritableRule, DataFieldPropertyWritableRule
+        DataDefinitionPartialRule, NestedDataDefinitionPartialRule, DataFieldWritableRule, DataFieldPropertyWritableRule,
+        DataFieldRedundantTagRule, DataFieldNoVVReadWriteRule, DataFieldYamlSerializableRule
     );
 
     public override void Initialize(AnalysisContext context)
@@ -65,23 +102,31 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.None);
         context.EnableConcurrentExecution();
 
-        context.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.ClassDeclaration);
-        context.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.StructDeclaration);
-        context.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.RecordDeclaration);
-        context.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.RecordStructDeclaration);
-        context.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.InterfaceDeclaration);
+        context.RegisterSymbolStartAction(symbolContext =>
+        {
+            if (symbolContext.Symbol is not INamedTypeSymbol typeSymbol)
+                return;
 
-        context.RegisterSyntaxNodeAction(AnalyzeDataField, SyntaxKind.FieldDeclaration);
-        context.RegisterSyntaxNodeAction(AnalyzeDataFieldProperty, SyntaxKind.PropertyDeclaration);
+            if (!IsDataDefinition(typeSymbol))
+                return;
+
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.ClassDeclaration);
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.StructDeclaration);
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.RecordDeclaration);
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.RecordStructDeclaration);
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataDefinition, SyntaxKind.InterfaceDeclaration);
+
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataField, SyntaxKind.FieldDeclaration);
+            symbolContext.RegisterSyntaxNodeAction(AnalyzeDataFieldProperty, SyntaxKind.PropertyDeclaration);
+        }, SymbolKind.NamedType);
     }
 
-    private void AnalyzeDataDefinition(SyntaxNodeAnalysisContext context)
+    private static void AnalyzeDataDefinition(SyntaxNodeAnalysisContext context)
     {
         if (context.Node is not TypeDeclarationSyntax declaration)
             return;
 
-        var type = context.SemanticModel.GetDeclaredSymbol(declaration)!;
-        if (!IsDataDefinition(type))
+        if (context.ContainingSymbol is not INamedTypeSymbol type)
             return;
 
         if (!IsPartial(declaration))
@@ -92,7 +137,7 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         var containingType = type.ContainingType;
         while (containingType != null)
         {
-            var containingTypeDeclaration = (TypeDeclarationSyntax) containingType.DeclaringSyntaxReferences[0].GetSyntax();
+            var containingTypeDeclaration = (TypeDeclarationSyntax)containingType.DeclaringSyntaxReferences[0].GetSyntax();
             if (!IsPartial(containingTypeDeclaration))
             {
                 context.ReportDiagnostic(Diagnostic.Create(NestedDataDefinitionPartialRule, containingTypeDeclaration.Keyword.GetLocation(), containingType.Name, type.Name));
@@ -102,60 +147,111 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         }
     }
 
-    private void AnalyzeDataField(SyntaxNodeAnalysisContext context)
+    private static void AnalyzeDataField(SyntaxNodeAnalysisContext context)
     {
         if (context.Node is not FieldDeclarationSyntax field)
             return;
 
-        var typeDeclaration = field.FirstAncestorOrSelf<TypeDeclarationSyntax>();
-        if (typeDeclaration == null)
-            return;
-
-        var type = context.SemanticModel.GetDeclaredSymbol(typeDeclaration)!;
-        if (!IsDataDefinition(type))
+        if (context.ContainingSymbol?.ContainingType is not INamedTypeSymbol type)
             return;
 
         foreach (var variable in field.Declaration.Variables)
         {
             var fieldSymbol = context.SemanticModel.GetDeclaredSymbol(variable);
+
             if (fieldSymbol == null)
                 continue;
 
+            if (!IsDataField(fieldSymbol, out _, out var datafieldAttribute))
+                continue;
+
             if (IsReadOnlyDataField(type, fieldSymbol))
             {
-                context.ReportDiagnostic(Diagnostic.Create(DataFieldWritableRule, context.Node.GetLocation(), fieldSymbol.Name, type.Name));
+                TryGetModifierLocation(field, SyntaxKind.ReadOnlyKeyword, out var location);
+                context.ReportDiagnostic(Diagnostic.Create(DataFieldWritableRule, location, fieldSymbol.Name, type.Name));
+            }
+
+            if (HasRedundantTag(fieldSymbol, datafieldAttribute))
+            {
+                TryGetAttributeLocation(field, DataFieldAttributeName, out var location);
+                context.ReportDiagnostic(Diagnostic.Create(DataFieldRedundantTagRule, location, fieldSymbol.Name, type.Name));
+            }
+
+            if (HasVVReadWrite(fieldSymbol))
+            {
+                TryGetAttributeLocation(field, ViewVariablesAttributeName, out var location);
+                context.ReportDiagnostic(Diagnostic.Create(DataFieldNoVVReadWriteRule, location, fieldSymbol.Name, type.Name));
+            }
+
+            if (context.SemanticModel.GetSymbolInfo(field.Declaration.Type).Symbol is not ITypeSymbol fieldTypeSymbol)
+                continue;
+
+            if (IsNotYamlSerializable(fieldSymbol, fieldTypeSymbol))
+            {
+                context.ReportDiagnostic(Diagnostic.Create(DataFieldYamlSerializableRule,
+                    (context.Node as FieldDeclarationSyntax)?.Declaration.Type.GetLocation(),
+                    fieldSymbol.Name,
+                    type.Name,
+                    fieldTypeSymbol.MetadataName
+                ));
             }
         }
     }
 
-    private void AnalyzeDataFieldProperty(SyntaxNodeAnalysisContext context)
+    private static void AnalyzeDataFieldProperty(SyntaxNodeAnalysisContext context)
     {
         if (context.Node is not PropertyDeclarationSyntax property)
             return;
 
-        var typeDeclaration = property.FirstAncestorOrSelf<TypeDeclarationSyntax>();
-        if (typeDeclaration == null)
+        if (context.ContainingSymbol is not IPropertySymbol propertySymbol)
             return;
 
-        var type = context.SemanticModel.GetDeclaredSymbol(typeDeclaration)!;
-        if (!IsDataDefinition(type) || type.IsRecord || type.IsValueType)
+        if (propertySymbol.ContainingType is not INamedTypeSymbol type)
+            return;
+
+        if (type.IsRecord || type.IsValueType)
             return;
 
-        var propertySymbol = context.SemanticModel.GetDeclaredSymbol(property);
         if (propertySymbol == null)
             return;
 
+        if (!IsDataField(propertySymbol, out _, out var datafieldAttribute))
+            return;
+
         if (IsReadOnlyDataField(type, propertySymbol))
         {
-            context.ReportDiagnostic(Diagnostic.Create(DataFieldPropertyWritableRule, context.Node.GetLocation(), propertySymbol.Name, type.Name));
+            var location = property.AccessorList != null ? property.AccessorList.GetLocation() : property.GetLocation();
+            context.ReportDiagnostic(Diagnostic.Create(DataFieldPropertyWritableRule, location, propertySymbol.Name, type.Name));
+        }
+
+        if (HasRedundantTag(propertySymbol, datafieldAttribute))
+        {
+            TryGetAttributeLocation(property, DataFieldAttributeName, out var location);
+            context.ReportDiagnostic(Diagnostic.Create(DataFieldRedundantTagRule, location, propertySymbol.Name, type.Name));
+        }
+
+        if (HasVVReadWrite(propertySymbol))
+        {
+            TryGetAttributeLocation(property, ViewVariablesAttributeName, out var location);
+            context.ReportDiagnostic(Diagnostic.Create(DataFieldNoVVReadWriteRule, location, propertySymbol.Name, type.Name));
+        }
+
+        if (context.SemanticModel.GetSymbolInfo(property.Type).Symbol is not ITypeSymbol propertyTypeSymbol)
+            return;
+
+        if (IsNotYamlSerializable(propertySymbol, propertyTypeSymbol))
+        {
+            context.ReportDiagnostic(Diagnostic.Create(DataFieldYamlSerializableRule,
+                (context.Node as PropertyDeclarationSyntax)?.Type.GetLocation(),
+                propertySymbol.Name,
+                type.Name,
+                propertyTypeSymbol.Name
+            ));
         }
     }
 
     private static bool IsReadOnlyDataField(ITypeSymbol type, ISymbol field)
     {
-        if (!IsDataField(field, out _, out _))
-            return false;
-
         return IsReadOnlyMember(type, field);
     }
 
@@ -217,6 +313,38 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         return false;
     }
 
+    private static bool TryGetAttributeLocation(MemberDeclarationSyntax syntax, string attributeName, out Location location)
+    {
+        foreach (var attributeList in syntax.AttributeLists)
+        {
+            foreach (var attribute in attributeList.Attributes)
+            {
+                if (attribute.Name.ToString() != attributeName)
+                    continue;
+
+                location = attribute.GetLocation();
+                return true;
+            }
+        }
+        // Default to the declaration syntax's location
+        location = syntax.GetLocation();
+        return false;
+    }
+
+    private static bool TryGetModifierLocation(MemberDeclarationSyntax syntax, SyntaxKind modifierKind, out Location location)
+    {
+        foreach (var modifier in syntax.Modifiers)
+        {
+            if (modifier.IsKind(modifierKind))
+            {
+                location = modifier.GetLocation();
+                return true;
+            }
+        }
+        location = syntax.GetLocation();
+        return false;
+    }
+
     private static bool IsReadOnlyMember(ITypeSymbol type, ISymbol member)
     {
         if (member is IFieldSymbol field)
@@ -248,6 +376,56 @@ public sealed class DataDefinitionAnalyzer : DiagnosticAnalyzer
         return false;
     }
 
+    private static bool HasRedundantTag(ISymbol symbol, AttributeData datafieldAttribute)
+    {
+        // No args, no problem
+        if (datafieldAttribute.ConstructorArguments.Length == 0)
+            return false;
+
+        // If a tag is explicitly specified, it will be the first argument...
+        var tagArgument = datafieldAttribute.ConstructorArguments[0];
+        // ...but the first arg could also something else, since tag is optional
+        // so we make sure that it's a string
+        if (tagArgument.Value is not string explicitName)
+            return false;
+
+        // Get the name that sourcegen would provide
+        var automaticName = DataDefinitionUtility.AutoGenerateTag(symbol.Name);
+
+        // If the explicit name matches the sourcegen name, we have a redundancy
+        return explicitName == automaticName;
+    }
+
+    private static bool HasVVReadWrite(ISymbol symbol)
+    {
+        // Make sure it has ViewVariablesAttribute
+        AttributeData? viewVariablesAttribute = null;
+        foreach (var attr in symbol.GetAttributes())
+        {
+            if (attr.AttributeClass?.ToDisplayString() == ViewVariablesNamespace)
+            {
+                viewVariablesAttribute = attr;
+            }
+        }
+        if (viewVariablesAttribute == null)
+            return false;
+
+        // Default is ReadOnly, which is fine
+        if (viewVariablesAttribute.ConstructorArguments.Length == 0)
+            return false;
+
+        var accessArgument = viewVariablesAttribute.ConstructorArguments[0];
+        if (accessArgument.Value is not byte accessByte)
+            return false;
+
+        return (VVAccess)accessByte == VVAccess.ReadWrite;
+    }
+
+    private static bool IsNotYamlSerializable(ISymbol field, ITypeSymbol type)
+    {
+        return HasAttribute(type, NotYamlSerializableName);
+    }
+
     private static bool IsImplicitDataDefinition(ITypeSymbol type)
     {
         if (HasAttribute(type, ImplicitDataDefinitionNamespace))

Robust.Analyzers/DataDefinitionFixer.cs

@@ -1,8 +1,5 @@
 #nullable enable
 using System.Collections.Immutable;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CodeActions;
 using Microsoft.CodeAnalysis.CodeFixes;
@@ -16,8 +13,13 @@ namespace Robust.Analyzers;
 [ExportCodeFixProvider(LanguageNames.CSharp)]
 public sealed class DefinitionFixer : CodeFixProvider
 {
+    private const string DataFieldAttributeName = "DataField";
+
+    private const string ViewVariablesAttributeName = "ViewVariables";
+
     public override ImmutableArray<string> FixableDiagnosticIds => ImmutableArray.Create(
-        IdDataDefinitionPartial, IdNestedDataDefinitionPartial, IdDataFieldWritable, IdDataFieldPropertyWritable
+        IdDataDefinitionPartial, IdNestedDataDefinitionPartial, IdDataFieldWritable, IdDataFieldPropertyWritable,
+        IdDataFieldRedundantTag, IdDataFieldNoVVReadWrite
     );
 
     public override Task RegisterCodeFixesAsync(CodeFixContext context)
@@ -34,6 +36,10 @@ public sealed class DefinitionFixer : CodeFixProvider
                     return RegisterDataFieldFix(context, diagnostic);
                 case IdDataFieldPropertyWritable:
                     return RegisterDataFieldPropertyFix(context, diagnostic);
+                case IdDataFieldRedundantTag:
+                    return RegisterRedundantTagFix(context, diagnostic);
+                case IdDataFieldNoVVReadWrite:
+                    return RegisterVVReadWriteFix(context, diagnostic);
             }
         }
 
@@ -72,6 +78,110 @@ public sealed class DefinitionFixer : CodeFixProvider
         return document.WithSyntaxRoot(root);
     }
 
+    private static async Task RegisterRedundantTagFix(CodeFixContext context, Diagnostic diagnostic)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken);
+        var span = diagnostic.Location.SourceSpan;
+        var token = root?.FindToken(span.Start).Parent?.AncestorsAndSelf().OfType<MemberDeclarationSyntax>().First();
+
+        if (token == null)
+            return;
+
+        // Find the DataField attribute
+        AttributeSyntax? dataFieldAttribute = null;
+        foreach (var attributeList in token.AttributeLists)
+        {
+            foreach (var attribute in attributeList.Attributes)
+            {
+                if (attribute.Name.ToString() == DataFieldAttributeName)
+                {
+                    dataFieldAttribute = attribute;
+                    break;
+                }
+            }
+            if (dataFieldAttribute != null)
+                break;
+        }
+
+        if (dataFieldAttribute == null)
+            return;
+
+        context.RegisterCodeFix(CodeAction.Create(
+            "Remove explicitly set tag",
+            c => RemoveRedundantTag(context.Document, dataFieldAttribute, c),
+            "Remove explicitly set tag"
+        ), diagnostic);
+    }
+
+    private static async Task<Document> RemoveRedundantTag(Document document, AttributeSyntax syntax, CancellationToken cancellation)
+    {
+        var root = (CompilationUnitSyntax?) await document.GetSyntaxRootAsync(cancellation);
+
+        if (syntax.ArgumentList == null)
+            return document;
+
+        AttributeSyntax? newSyntax;
+        if (syntax.ArgumentList.Arguments.Count == 1)
+        {
+            // If this is the only argument, delete the ArgumentList so we don't leave empty parentheses
+            newSyntax = syntax.RemoveNode(syntax.ArgumentList, SyntaxRemoveOptions.KeepNoTrivia);
+        }
+        else
+        {
+            // Remove the first argument, which is the tag
+            var newArgs = syntax.ArgumentList.Arguments.RemoveAt(0);
+            var newArgList = syntax.ArgumentList.WithArguments(newArgs);
+            // Construct a new attribute with the tag removed
+            newSyntax = syntax.WithArgumentList(newArgList);
+        }
+
+        root = root!.ReplaceNode(syntax, newSyntax!);
+
+        return document.WithSyntaxRoot(root);
+    }
+
+    private static async Task RegisterVVReadWriteFix(CodeFixContext context, Diagnostic diagnostic)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken);
+        var span = diagnostic.Location.SourceSpan;
+        var token = root?.FindToken(span.Start).Parent?.AncestorsAndSelf().OfType<MemberDeclarationSyntax>().First();
+
+        if (token == null)
+            return;
+
+        context.RegisterCodeFix(CodeAction.Create(
+            "Remove ViewVariables attribute",
+            c => RemoveVVAttribute(context.Document, token, c),
+            "Remove ViewVariables attribute"
+        ), diagnostic);
+    }
+
+    private static async Task<Document> RemoveVVAttribute(Document document, MemberDeclarationSyntax syntax, CancellationToken cancellation)
+    {
+        var root = (CompilationUnitSyntax?) await document.GetSyntaxRootAsync(cancellation);
+
+        var newLists = new SyntaxList<AttributeListSyntax>();
+        foreach (var attributeList in syntax.AttributeLists)
+        {
+            var attributes = new SeparatedSyntaxList<AttributeSyntax>();
+            foreach (var attribute in attributeList.Attributes)
+            {
+                if (attribute.Name.ToString() != ViewVariablesAttributeName)
+                {
+                    attributes = attributes.Add(attribute);
+                }
+            }
+            // Don't add empty lists []
+            if (attributes.Count > 0)
+                newLists = newLists.Add(attributeList.WithAttributes(attributes));
+        }
+        var newSyntax = syntax.WithAttributeLists(newLists);
+
+        root = root!.ReplaceNode(syntax, newSyntax);
+
+        return document.WithSyntaxRoot(root);
+    }
+
     private static async Task RegisterDataFieldFix(CodeFixContext context, Diagnostic diagnostic)
     {
         var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken);

Robust.Analyzers/DuplicateDependencyAnalyzer.cs

@@ -0,0 +1,126 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+#nullable enable
+
+/// <summary>
+/// Analyzer that detects duplicate <c>[Dependency]</c> fields inside a single type.
+/// </summary>
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class DuplicateDependencyAnalyzer : DiagnosticAnalyzer
+{
+    private const string DependencyAttributeType = "Robust.Shared.IoC.DependencyAttribute";
+
+    private static readonly DiagnosticDescriptor Rule = new(
+        Diagnostics.IdDuplicateDependency,
+        "Duplicate dependency field",
+        "Another [Dependency] field of type '{0}' already exists in this type with field '{1}'",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.EnableConcurrentExecution();
+        context.RegisterCompilationStartAction(compilationContext =>
+        {
+            var dependencyAttributeType = compilationContext.Compilation.GetTypeByMetadataName(DependencyAttributeType);
+            if (dependencyAttributeType == null)
+                return;
+
+            compilationContext.RegisterSymbolStartAction(symbolContext =>
+                {
+                    var typeSymbol = (INamedTypeSymbol)symbolContext.Symbol;
+                    // Only deal with non-static classes, doesn't make sense to have dependencies in anything else.
+                    if (typeSymbol.TypeKind != TypeKind.Class || typeSymbol.IsStatic)
+                        return;
+
+                    var state = new AnalyzerState(dependencyAttributeType);
+                    symbolContext.RegisterSyntaxNodeAction(state.AnalyzeField, SyntaxKind.FieldDeclaration);
+                    symbolContext.RegisterSymbolEndAction(state.End);
+                },
+                SymbolKind.NamedType);
+        });
+    }
+
+    private sealed class AnalyzerState(INamedTypeSymbol dependencyAttributeType)
+    {
+        private readonly Dictionary<ITypeSymbol, List<IFieldSymbol>> _dependencyFields = new(SymbolEqualityComparer.Default);
+
+        public void AnalyzeField(SyntaxNodeAnalysisContext context)
+        {
+            var field = (FieldDeclarationSyntax)context.Node;
+            if (field.AttributeLists.Count == 0)
+                return;
+
+            if (context.ContainingSymbol is not IFieldSymbol fieldSymbol)
+                return;
+
+            // Can't have [Dependency]s for non-reference types.
+            if (!fieldSymbol.Type.IsReferenceType)
+                return;
+
+            if (!IsDependency(context.ContainingSymbol))
+                return;
+
+            lock (_dependencyFields)
+            {
+                if (!_dependencyFields.TryGetValue(fieldSymbol.Type, out var dependencyFields))
+                {
+                    dependencyFields = [];
+                    _dependencyFields.Add(fieldSymbol.Type, dependencyFields);
+                }
+
+                dependencyFields.Add(fieldSymbol);
+            }
+        }
+
+        private bool IsDependency(ISymbol symbol)
+        {
+            foreach (var attributeData in symbol.GetAttributes())
+            {
+                if (SymbolEqualityComparer.Default.Equals(attributeData.AttributeClass, dependencyAttributeType))
+                    return true;
+            }
+
+            return false;
+        }
+
+        public void End(SymbolAnalysisContext context)
+        {
+            lock (_dependencyFields)
+            {
+                foreach (var pair in _dependencyFields)
+                {
+                    var fieldType = pair.Key;
+                    var fields = pair.Value;
+                    if (fields.Count <= 1)
+                        continue;
+
+                    // Sort so we can have deterministic order to skip reporting for a single field.
+                    // Whichever sorts first doesn't get reported.
+                    fields.Sort(static (a, b) => string.Compare(a.Name, b.Name, StringComparison.Ordinal));
+
+                    // Start at index 1 to skip first field.
+                    var firstField = fields[0];
+                    for (var i = 1; i < fields.Count; i++)
+                    {
+                        var field = fields[i];
+
+                        context.ReportDiagnostic(
+                            Diagnostic.Create(Rule, field.Locations[0], fieldType.ToDisplayString(), firstField.Name));
+                    }
+                }
+            }
+        }
+    }
+}

Robust.Analyzers/ForbidLiteralAnalyzer.cs

@@ -0,0 +1,101 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Operations;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class ForbidLiteralAnalyzer : DiagnosticAnalyzer
+{
+    private const string ForbidLiteralType = "Robust.Shared.Analyzers.ForbidLiteralAttribute";
+
+    public static DiagnosticDescriptor ForbidLiteralRule = new(
+        Diagnostics.IdForbidLiteral,
+        "Parameter forbids literal values",
+        "The {0} parameter of {1} forbids literal values",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true,
+        "Pass in a validated wrapper type like ProtoId, or a const or static value."
+    );
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [ForbidLiteralRule];
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.ReportDiagnostics);
+        context.EnableConcurrentExecution();
+        context.RegisterOperationAction(AnalyzeOperation, OperationKind.Invocation);
+    }
+
+    private void AnalyzeOperation(OperationAnalysisContext context)
+    {
+        if (context.Operation is not IInvocationOperation invocationOperation)
+            return;
+
+        // Check each parameter of the method invocation
+        foreach (var argumentOperation in invocationOperation.Arguments)
+        {
+            // Check for our attribute on the parameter
+            if (!AttributeHelper.HasAttribute(argumentOperation.Parameter, ForbidLiteralType, out _))
+                continue;
+
+            // Handle parameters using the params keyword
+            if (argumentOperation.Syntax is InvocationExpressionSyntax subExpressionSyntax)
+            {
+                // Check each param value
+                foreach (var subArgument in subExpressionSyntax.ArgumentList.Arguments)
+                {
+                    CheckArgumentSyntax(context, argumentOperation, subArgument);
+                }
+                continue;
+            }
+
+            // Not params, so just check the single parameter
+            if (argumentOperation.Syntax is not ArgumentSyntax argumentSyntax)
+                continue;
+
+            CheckArgumentSyntax(context, argumentOperation, argumentSyntax);
+        }
+    }
+
+    private void CheckArgumentSyntax(OperationAnalysisContext context, IArgumentOperation operation, ArgumentSyntax argumentSyntax)
+    {
+        // Handle collection types
+        if (argumentSyntax.Expression is CollectionExpressionSyntax collectionExpressionSyntax)
+        {
+            // Check each value of the collection
+            foreach (var elementSyntax in collectionExpressionSyntax.Elements)
+            {
+                if (elementSyntax is not ExpressionElementSyntax expressionSyntax)
+                    continue;
+
+                // Check if a literal was passed in
+                if (expressionSyntax.Expression is not LiteralExpressionSyntax)
+                    continue;
+
+                context.ReportDiagnostic(Diagnostic.Create(ForbidLiteralRule,
+                    expressionSyntax.GetLocation(),
+                    operation.Parameter.Name,
+                    (context.Operation as IInvocationOperation).TargetMethod.Name
+                ));
+            }
+            return;
+        }
+
+        // Not a collection, just a single value to check
+        // Check if it's a literal
+        if (argumentSyntax.Expression is not LiteralExpressionSyntax)
+            return;
+
+        context.ReportDiagnostic(Diagnostic.Create(ForbidLiteralRule,
+            argumentSyntax.GetLocation(),
+            operation.Parameter.Name,
+            (context.Operation as IInvocationOperation).TargetMethod.Name
+        ));
+    }
+}

Robust.Analyzers/MustCallBaseAnalyzer.cs

@@ -0,0 +1,111 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+#nullable enable
+
+/// <summary>
+/// Enforces <c>MustCallBaseAttribute</c>.
+/// </summary>
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class MustCallBaseAnalyzer : DiagnosticAnalyzer
+{
+    private const string Attribute = "Robust.Shared.Analyzers.MustCallBaseAttribute";
+
+    private static readonly DiagnosticDescriptor Rule = new(
+        Diagnostics.IdMustCallBase,
+        "No base call in overriden function",
+        "Overriders of this function must always call the base function",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        isEnabledByDefault: true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.EnableConcurrentExecution();
+        context.RegisterSymbolAction(AnalyzeSymbol, SymbolKind.Method);
+    }
+
+    private static void AnalyzeSymbol(SymbolAnalysisContext context)
+    {
+        if (context.Symbol is not IMethodSymbol { IsOverride: true } method)
+            return;
+
+        var attrSymbol = context.Compilation.GetTypeByMetadataName(Attribute);
+        if (attrSymbol == null)
+            return;
+
+        if (DoesMethodOverriderHaveAttribute(method, attrSymbol) is not { } data)
+            return;
+
+        if (data is { onlyOverrides: true, depth: < 2 })
+            return;
+
+        var syntax = (MethodDeclarationSyntax) method.DeclaringSyntaxReferences[0].GetSyntax();
+        if (HasBaseCall(syntax))
+            return;
+
+        var diag = Diagnostic.Create(Rule, syntax.Identifier.GetLocation());
+        context.ReportDiagnostic(diag);
+    }
+
+    private static (int depth, bool onlyOverrides)? DoesMethodOverriderHaveAttribute(
+        IMethodSymbol method,
+        INamedTypeSymbol attributeSymbol)
+    {
+        var depth = 0;
+        while (method.OverriddenMethod != null)
+        {
+            depth += 1;
+            method = method.OverriddenMethod;
+            if (GetAttribute(method, attributeSymbol) is not { } attribute)
+                continue;
+
+            var onlyOverrides = attribute.ConstructorArguments is [{Kind: TypedConstantKind.Primitive, Value: true}];
+            return (depth, onlyOverrides);
+        }
+
+        return null;
+    }
+
+    private static bool HasBaseCall(MethodDeclarationSyntax syntax)
+    {
+        return syntax.Accept(new BaseCallLocator());
+    }
+
+    private static AttributeData? GetAttribute(ISymbol namedTypeSymbol, INamedTypeSymbol attrSymbol)
+    {
+        return namedTypeSymbol.GetAttributes()
+            .SingleOrDefault(a => SymbolEqualityComparer.Default.Equals(a.AttributeClass, attrSymbol));
+    }
+
+    private sealed class BaseCallLocator : CSharpSyntaxVisitor<bool>
+    {
+        public override bool VisitBaseExpression(BaseExpressionSyntax node)
+        {
+            return true;
+        }
+
+        public override bool DefaultVisit(SyntaxNode node)
+        {
+            foreach (var childNode in node.ChildNodes())
+            {
+                if (childNode is not CSharpSyntaxNode cSharpSyntax)
+                    continue;
+
+                if (cSharpSyntax.Accept(this))
+                    return true;
+            }
+
+            return false;
+        }
+    }
+}

Robust.Analyzers/NoUncachedRegexAnalyzer.cs

@@ -0,0 +1,66 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Operations;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class NoUncachedRegexAnalyzer : DiagnosticAnalyzer
+{
+    private const string RegexTypeName = "Regex";
+    private const string RegexType = $"System.Text.RegularExpressions.{RegexTypeName}";
+
+    private static readonly DiagnosticDescriptor Rule = new (
+        Diagnostics.IdUncachedRegex,
+        "Use of uncached static Regex function",
+        "Usage of a static Regex function that takes in a pattern string. This can cause constant re-parsing of the pattern.",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(Rule);
+
+    public static readonly HashSet<string> BadFunctions =
+    [
+        "Count",
+        "EnumerateMatches",
+        "IsMatch",
+        "Match",
+        "Matches",
+        "Replace",
+        "Split"
+    ];
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.EnableConcurrentExecution();
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.RegisterOperationAction(CheckInvocation, OperationKind.Invocation);
+    }
+
+    private static void CheckInvocation(OperationAnalysisContext context)
+    {
+        if (context.Operation is not IInvocationOperation invocation)
+            return;
+
+        // All Regex functions we care about are static.
+        var targetMethod = invocation.TargetMethod;
+        if (!targetMethod.IsStatic)
+            return;
+
+        // Bail early.
+        if (targetMethod.ContainingType.Name != "Regex")
+            return;
+
+        var regexType = context.Compilation.GetTypeByMetadataName(RegexType);
+        if (!SymbolEqualityComparer.Default.Equals(regexType, targetMethod.ContainingType))
+            return;
+
+        if (!BadFunctions.Contains(targetMethod.Name))
+            return;
+
+        context.ReportDiagnostic(Diagnostic.Create(Rule, invocation.Syntax.GetLocation()));
+    }
+}

Robust.Analyzers/ObsoleteInheritanceAnalyzer.cs

@@ -0,0 +1,75 @@
+#nullable enable
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class ObsoleteInheritanceAnalyzer : DiagnosticAnalyzer
+{
+    private const string Attribute = "Robust.Shared.Analyzers.ObsoleteInheritanceAttribute";
+
+    public static readonly DiagnosticDescriptor Rule = new(
+        Diagnostics.IdObsoleteInheritance,
+        "Parent type has obsoleted inheritance",
+        "Type '{0}' inherits from '{1}', which has obsoleted inheriting from itself",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+    public static readonly DiagnosticDescriptor RuleWithMessage = new(
+        Diagnostics.IdObsoleteInheritanceWithMessage,
+        "Parent type has obsoleted inheritance",
+        "Type '{0}' inherits from '{1}', which has obsoleted inheriting from itself: \"{2}\"",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [Rule, RuleWithMessage];
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.EnableConcurrentExecution();
+        context.RegisterSymbolAction(CheckClass, SymbolKind.NamedType);
+    }
+
+    private static void CheckClass(SymbolAnalysisContext context)
+    {
+        if (context.Symbol is not INamedTypeSymbol typeSymbol)
+            return;
+
+        if (typeSymbol.IsValueType || typeSymbol.BaseType is not { } baseType)
+            return;
+
+        if (!AttributeHelper.HasAttribute(baseType, Attribute, out var data))
+            return;
+
+        var location = context.Symbol.Locations[0];
+
+        if (GetMessageFromAttributeData(data) is { } message)
+        {
+            context.ReportDiagnostic(Diagnostic.Create(
+                RuleWithMessage,
+                location,
+                [typeSymbol.Name, baseType.Name, message]));
+        }
+        else
+        {
+            context.ReportDiagnostic(Diagnostic.Create(
+                Rule,
+                location,
+                [typeSymbol.Name, baseType.Name]));
+        }
+    }
+
+    private static string? GetMessageFromAttributeData(AttributeData data)
+    {
+        if (data.ConstructorArguments is not [var message, ..])
+            return null;
+
+        return message.Value as string;
+    }
+}

Robust.Analyzers/PreferNonGenericVariantForAnalyzer.cs

@@ -0,0 +1,65 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Operations;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class PreferNonGenericVariantForAnalyzer : DiagnosticAnalyzer
+{
+    private const string AttributeType = "Robust.Shared.Analyzers.PreferNonGenericVariantForAttribute";
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(
+        UseNonGenericVariantDescriptor
+    );
+
+    private static readonly DiagnosticDescriptor UseNonGenericVariantDescriptor = new(
+        Diagnostics.IdUseNonGenericVariant,
+        "Consider using the non-generic variant of this method",
+        "Use the non-generic variant of this method for type {0}",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true,
+        "Use the generic variant of this method.");
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.ReportDiagnostics | GeneratedCodeAnalysisFlags.Analyze);
+        context.EnableConcurrentExecution();
+        context.RegisterOperationAction(CheckForNonGenericVariant, OperationKind.Invocation);
+    }
+
+    private void CheckForNonGenericVariant(OperationAnalysisContext obj)
+    {
+        if (obj.Operation is not IInvocationOperation invocationOperation) return;
+
+        var preferNonGenericAttribute = obj.Compilation.GetTypeByMetadataName(AttributeType);
+
+        HashSet<ITypeSymbol> forTypes = [];
+        foreach (var attribute in invocationOperation.TargetMethod.GetAttributes())
+        {
+            if (!SymbolEqualityComparer.Default.Equals(attribute.AttributeClass, preferNonGenericAttribute))
+                continue;
+
+            foreach (var type in attribute.ConstructorArguments[0].Values)
+                forTypes.Add((ITypeSymbol)type.Value);
+
+            break;
+        }
+
+        if (forTypes == null)
+            return;
+
+        foreach (var typeArg in invocationOperation.TargetMethod.TypeArguments)
+        {
+            if (forTypes.Contains(typeArg))
+            {
+                obj.ReportDiagnostic(
+                Diagnostic.Create(UseNonGenericVariantDescriptor,
+                    invocationOperation.Syntax.GetLocation(), typeArg.Name));
+            }
+        }
+    }
+}

Robust.Analyzers/PreferOtherTypeAnalyzer.cs

@@ -0,0 +1,75 @@
+#nullable enable
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class PreferOtherTypeAnalyzer : DiagnosticAnalyzer
+{
+    private const string AttributeType = "Robust.Shared.Analyzers.PreferOtherTypeAttribute";
+
+    private static readonly DiagnosticDescriptor PreferOtherTypeDescriptor = new(
+        Diagnostics.IdPreferOtherType,
+        "Use the specific type",
+        "Use the specific type {0} instead of {1} when the type argument is {2}",
+        "Usage",
+        DiagnosticSeverity.Error,
+        true,
+        "Use the specific type.");
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(
+        PreferOtherTypeDescriptor
+    );
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.ReportDiagnostics | GeneratedCodeAnalysisFlags.Analyze);
+        context.EnableConcurrentExecution();
+        context.RegisterSyntaxNodeAction(AnalyzeField, SyntaxKind.VariableDeclaration);
+    }
+
+    private void AnalyzeField(SyntaxNodeAnalysisContext context)
+    {
+        if (context.Node is not VariableDeclarationSyntax node)
+            return;
+
+        // Get the type of the generic being used
+        if (node.Type is not GenericNameSyntax genericName)
+            return;
+        var genericSyntax = genericName.TypeArgumentList.Arguments[0];
+        if (context.SemanticModel.GetSymbolInfo(genericSyntax).Symbol is not { } genericType)
+            return;
+
+        // Look for the PreferOtherTypeAttribute
+        var symbolInfo = context.SemanticModel.GetSymbolInfo(node.Type);
+        if (symbolInfo.Symbol?.GetAttributes() is not { } attributes)
+            return;
+
+        var preferOtherTypeAttribute = context.Compilation.GetTypeByMetadataName(AttributeType);
+
+        foreach (var attribute in attributes)
+        {
+            if (!SymbolEqualityComparer.Default.Equals(attribute.AttributeClass, preferOtherTypeAttribute))
+                continue;
+
+            // See if the generic type argument matches the type the attribute specifies
+            if (attribute.ConstructorArguments[0].Value is not ITypeSymbol checkedType)
+                return;
+            if (!SymbolEqualityComparer.Default.Equals(checkedType, genericType))
+                continue;
+
+            if (attribute.ConstructorArguments[1].Value is not ITypeSymbol replacementType)
+                continue;
+            context.ReportDiagnostic(Diagnostic.Create(PreferOtherTypeDescriptor,
+                context.Node.GetLocation(),
+                replacementType.Name,
+                symbolInfo.Symbol.Name,
+                genericType.Name));
+        }
+    }
+}

Robust.Analyzers/PreferOtherTypeFixer.cs

@@ -0,0 +1,97 @@
+#nullable enable
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CodeActions;
+using Microsoft.CodeAnalysis.CodeFixes;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using static Robust.Roslyn.Shared.Diagnostics;
+
+namespace Robust.Analyzers;
+
+[ExportCodeFixProvider(LanguageNames.CSharp)]
+public sealed class PreferOtherTypeFixer : CodeFixProvider
+{
+    private const string PreferOtherTypeAttributeName = "PreferOtherTypeAttribute";
+
+    public override ImmutableArray<string> FixableDiagnosticIds => ImmutableArray.Create(
+        IdPreferOtherType
+    );
+
+    public override FixAllProvider GetFixAllProvider()
+    {
+        return WellKnownFixAllProviders.BatchFixer;
+    }
+
+    public override Task RegisterCodeFixesAsync(CodeFixContext context)
+    {
+        foreach (var diagnostic in context.Diagnostics)
+        {
+            switch (diagnostic.Id)
+            {
+                case IdPreferOtherType:
+                    return RegisterReplaceType(context, diagnostic);
+            }
+        }
+
+        return Task.CompletedTask;
+    }
+
+    private static async Task RegisterReplaceType(CodeFixContext context, Diagnostic diagnostic)
+    {
+        var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken);
+        var span = diagnostic.Location.SourceSpan;
+        var token = root?.FindToken(span.Start).Parent?.AncestorsAndSelf().OfType<VariableDeclarationSyntax>().First();
+
+        if (token == null)
+            return;
+
+        context.RegisterCodeFix(CodeAction.Create(
+            "Replace type",
+            c => ReplaceType(context.Document, token, c),
+            "Replace type"
+        ), diagnostic);
+    }
+
+    private static async Task<Document> ReplaceType(Document document, VariableDeclarationSyntax syntax, CancellationToken cancellation)
+    {
+        var root = (CompilationUnitSyntax?) await document.GetSyntaxRootAsync(cancellation);
+        var model = await document.GetSemanticModelAsync(cancellation);
+
+        if (model == null)
+            return document;
+
+        if (syntax.Type is not GenericNameSyntax genericNameSyntax)
+            return document;
+        var genericTypeSyntax = genericNameSyntax.TypeArgumentList.Arguments[0];
+        if (model.GetSymbolInfo(genericTypeSyntax).Symbol is not {} genericTypeSymbol)
+            return document;
+
+        var symbolInfo = model.GetSymbolInfo(syntax.Type);
+        if (symbolInfo.Symbol?.GetAttributes() is not { } attributes)
+            return document;
+
+        foreach (var attribute in attributes)
+        {
+            if (attribute.AttributeClass?.Name != PreferOtherTypeAttributeName)
+                continue;
+
+            if (attribute.ConstructorArguments[0].Value is not ITypeSymbol checkedTypeSymbol)
+                continue;
+
+            if (!SymbolEqualityComparer.Default.Equals(checkedTypeSymbol, genericTypeSymbol))
+                continue;
+
+            if (attribute.ConstructorArguments[1].Value is not ITypeSymbol replacementTypeSymbol)
+                continue;
+
+            var replacementIdentifier = SyntaxFactory.IdentifierName(replacementTypeSymbol.Name);
+            var replacementSyntax = syntax.WithType(replacementIdentifier);
+
+            root = root!.ReplaceNode(syntax, replacementSyntax);
+            return document.WithSyntaxRoot(root);
+        }
+
+        return document;
+    }
+}

Robust.Analyzers/PrototypeInstantiationAnalyzer.cs

@@ -0,0 +1,48 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Operations;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class PrototypeInstantiationAnalyzer : DiagnosticAnalyzer
+{
+    private const string PrototypeInterfaceType = "Robust.Shared.Prototypes.IPrototype";
+
+    public static readonly DiagnosticDescriptor Rule = new(
+        Diagnostics.IdPrototypeInstantiation,
+        "Do not instantiate prototypes directly",
+        "Do not instantiate prototypes directly. Prototypes should always be instantiated by the prototype manager.",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [Rule];
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.EnableConcurrentExecution();
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+        context.RegisterCompilationStartAction(static ctx =>
+        {
+            var prototypeInterface = ctx.Compilation.GetTypeByMetadataName(PrototypeInterfaceType);
+            if (prototypeInterface == null)
+                return;
+
+            ctx.RegisterOperationAction(symContext => Check(prototypeInterface, symContext), OperationKind.ObjectCreation);
+        });
+    }
+
+    private static void Check(INamedTypeSymbol prototypeInterface, OperationAnalysisContext ctx)
+    {
+        if (ctx.Operation is not IObjectCreationOperation { Type: { } resultType } creationOp)
+            return;
+
+        if (!TypeSymbolHelper.ImplementsInterface(resultType, prototypeInterface))
+            return;
+
+        ctx.ReportDiagnostic(Diagnostic.Create(Rule, creationOp.Syntax.GetLocation()));
+    }
+}

Robust.Analyzers/PrototypeNetSerializableAnalyzer.cs

@@ -0,0 +1,76 @@
+using System.Collections.Immutable;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Robust.Roslyn.Shared;
+
+namespace Robust.Analyzers;
+
+[DiagnosticAnalyzer(LanguageNames.CSharp)]
+public sealed class PrototypeNetSerializableAnalyzer : DiagnosticAnalyzer
+{
+    private const string PrototypeInterfaceType = "Robust.Shared.Prototypes.IPrototype";
+    private const string NetSerializableAttributeType = "Robust.Shared.Serialization.NetSerializableAttribute";
+
+    public static readonly DiagnosticDescriptor RuleNetSerializable = new(
+        Diagnostics.IdPrototypeNetSerializable,
+        "Prototypes should not be [NetSerializable]",
+        "Type {0} is a prototype and marked as [NetSerializable]. Prototypes should not be directly sent over the network, send their IDs instead.",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+
+    public static readonly DiagnosticDescriptor RuleSerializable = new(
+        Diagnostics.IdPrototypeSerializable,
+        "Prototypes should not be [Serializable]",
+        "Type {0} is a prototype and marked as [Serializable]. Prototypes should not be directly sent over the network, send their IDs instead.",
+        "Usage",
+        DiagnosticSeverity.Warning,
+        true);
+
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => [
+        RuleNetSerializable,
+        RuleSerializable
+    ];
+
+    public override void Initialize(AnalysisContext context)
+    {
+        context.EnableConcurrentExecution();
+        context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None);
+
+        context.RegisterCompilationStartAction(static ctx =>
+        {
+            var prototypeInterface = ctx.Compilation.GetTypeByMetadataName(PrototypeInterfaceType);
+            var netSerializableAttribute = ctx.Compilation.GetTypeByMetadataName(NetSerializableAttributeType);
+
+            if (prototypeInterface == null || netSerializableAttribute == null)
+                return;
+
+            ctx.RegisterSymbolAction(symbolContext => CheckClass(prototypeInterface, netSerializableAttribute, symbolContext), SymbolKind.NamedType);
+        });
+    }
+
+    private static void CheckClass(
+        INamedTypeSymbol prototypeInterface,
+        INamedTypeSymbol netSerializableAttribute,
+        SymbolAnalysisContext symbolContext)
+    {
+        if (symbolContext.Symbol is not INamedTypeSymbol symbol)
+            return;
+
+        if (!TypeSymbolHelper.ImplementsInterface(symbol, prototypeInterface))
+            return;
+
+        if (AttributeHelper.HasAttribute(symbol, netSerializableAttribute, out _))
+        {
+            symbolContext.ReportDiagnostic(
+                Diagnostic.Create(RuleNetSerializable, symbol.Locations[0], symbol.ToDisplayString()));
+        }
+
+        if (symbol.IsSerializable)
+        {
+            symbolContext.ReportDiagnostic(
+                Diagnostic.Create(RuleSerializable, symbol.Locations[0], symbol.ToDisplayString()));
+        }
+    }
+}

Robust.Analyzers/Robust.Analyzers.csproj

@@ -16,6 +16,23 @@
     <Compile Include="..\Robust.Shared\Analyzers\PreferGenericVariantAttribute.cs" LinkBase="Implementations" />
   </ItemGroup>
 
+  <ItemGroup>
+    <!-- Needed for PreferNonGenericVariantAnalyzer. -->
+    <Compile Include="..\Robust.Shared\Analyzers\PreferNonGenericVariantForAttribute.cs" LinkBase="Implementations" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- Needed for PreferOtherTypeAnalyzer. -->
+    <Compile Include="..\Robust.Shared\Analyzers\PreferOtherTypeAttribute.cs" LinkBase="Implementations" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <!-- Needed for DataDefinitionAnalyzer. -->
+    <Compile Include="..\Robust.Shared\Serialization\Manager\Definition\DataDefinitionUtility.cs" LinkBase="Implementations" />
+    <Compile Include="..\Robust.Shared\ViewVariables\ViewVariablesAttribute.cs" LinkBase="Implementations" />
+    <Compile Include="..\Robust.Shared\Serialization\NetSerializableAttribute.cs" LinkBase="Implementations" />
+  </ItemGroup>
+
   <Import Project="../Robust.Roslyn.Shared/Robust.Roslyn.Shared.props" />
 
   <PropertyGroup>

Robust.Benchmarks/Configs/DefaultSQLConfig.cs

@@ -26,7 +26,8 @@ public sealed class DefaultSQLConfig : IConfig
 
     public IEnumerable<IExporter> GetExporters()
     {
-        yield return SQLExporter.Default;
+        //yield return SQLExporter.Default;
+        yield break;
     }
 
     public IEnumerable<IColumnProvider> GetColumnProviders() => DefaultConfig.Instance.GetColumnProviders();

Robust.Benchmarks/EntityManager/HasComponentBenchmark.cs

@@ -0,0 +1,96 @@
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Engines;
+using JetBrains.Annotations;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.UnitTesting.Server;
+
+namespace Robust.Benchmarks.EntityManager;
+
+[Virtual]
+public partial class HasComponentBenchmark
+{
+    private static readonly Consumer Consumer = new();
+
+    private ISimulation _simulation = default!;
+    private IEntityManager _entityManager = default!;
+
+    private ComponentRegistration _compReg = default!;
+
+    private A _dummyA = new();
+
+    [UsedImplicitly]
+    [Params(1, 10, 100, 1000)]
+    public int N;
+
+    [GlobalSetup]
+    public void GlobalSetup()
+    {
+        _simulation = RobustServerSimulation
+            .NewSimulation()
+            .RegisterComponents(f => f.RegisterClass<A>())
+            .InitializeInstance();
+
+        _entityManager = _simulation.Resolve<IEntityManager>();
+        var map = _simulation.CreateMap().Uid;
+        var coords = new EntityCoordinates(map, default);
+        _compReg = _entityManager.ComponentFactory.GetRegistration(typeof(A));
+
+        for (var i = 0; i < N; i++)
+        {
+            var uid = _entityManager.SpawnEntity(null, coords);
+            _entityManager.AddComponent<A>(uid);
+        }
+    }
+
+    [Benchmark]
+    public void HasComponentGeneric()
+    {
+        for (var i = 2; i <= N+1; i++)
+        {
+            var uid = new EntityUid(i);
+            var result = _entityManager.HasComponent<A>(uid);
+            Consumer.Consume(result);
+        }
+    }
+
+    [Benchmark]
+    public void HasComponentCompReg()
+    {
+        for (var i = 2; i <= N+1; i++)
+        {
+            var uid = new EntityUid(i);
+            var result = _entityManager.HasComponent(uid, _compReg);
+            Consumer.Consume(result);
+        }
+    }
+
+    [Benchmark]
+    public void HasComponentType()
+    {
+        for (var i = 2; i <= N+1; i++)
+        {
+            var uid = new EntityUid(i);
+            var result = _entityManager.HasComponent(uid, typeof(A));
+            Consumer.Consume(result);
+        }
+    }
+
+    [Benchmark]
+    public void HasComponentGetType()
+    {
+        for (var i = 2; i <= N+1; i++)
+        {
+            var uid = new EntityUid(i);
+            var type = _dummyA.GetType();
+            var result = _entityManager.HasComponent(uid, type);
+            Consumer.Consume(result);
+        }
+    }
+
+    [ComponentProtoName("A")]
+    public sealed partial class A : Component
+    {
+    }
+}

Robust.Benchmarks/Exporters/SQLExporter.cs

@@ -15,11 +15,10 @@ using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Design;
 using Npgsql;
 using Npgsql.Internal;
-using Npgsql.Internal.TypeHandlers;
-using Npgsql.Internal.TypeHandling;
 
 namespace Robust.Benchmarks.Exporters;
 
+/*
 public sealed class SQLExporter : IExporter
 {
     private static readonly JsonSerializerOptions JsonSerializerOptions = new JsonSerializerOptions
@@ -98,7 +97,9 @@ public sealed class SQLExporter : IExporter
 
     public string Name => "sql";
 }
+*/
 
+/*
 // https://github.com/npgsql/efcore.pg/issues/1107#issuecomment-945126627
 class JsonOverrideTypeHandlerResolverFactory : TypeHandlerResolverFactory
 {
@@ -138,6 +139,7 @@ class JsonOverrideTypeHandlerResolverFactory : TypeHandlerResolverFactory
             => null; // Let the built-in resolver do this
     }
 }
+*/
 
 public sealed class DesignTimeContextFactoryPostgres : IDesignTimeDbContextFactory<BenchmarkContext>
 {

Robust.Benchmarks/Physics/BoxStackBenchmark.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Numerics;
+using BenchmarkDotNet.Attributes;
+using Microsoft.Extensions.Configuration;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Collision.Shapes;
+using Robust.Shared.Physics.Components;
+using Robust.Shared.Physics.Dynamics;
+using Robust.Shared.Physics.Systems;
+using Robust.UnitTesting.Server;
+
+namespace Robust.Benchmarks.Physics;
+
+[Virtual]
+[MediumRunJob]
+public class PhysicsBoxStackBenchmark
+{
+    private ISimulation _sim = default!;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _sim = RobustServerSimulation.NewSimulation().InitializeInstance();
+
+        var entManager = _sim.Resolve<IEntityManager>();
+        entManager.System<SharedMapSystem>().CreateMap(out var mapId);
+        SetupTumbler(entManager, mapId);
+
+        for (var i = 0; i < 30; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    [Benchmark]
+    public void BoxStack()
+    {
+        var entManager = _sim.Resolve<IEntityManager>();
+
+        for (var i = 0; i < 10000; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    private void SetupTumbler(IEntityManager entManager, MapId mapId)
+    {
+        var physics = entManager.System<SharedPhysicsSystem>();
+        var fixtures = entManager.System<FixtureSystem>();
+
+        var groundUid = entManager.SpawnEntity(null, new MapCoordinates(0, 0, mapId));
+        var ground = entManager.AddComponent<PhysicsComponent>(groundUid);
+
+        var horizontal = new EdgeShape(new Vector2(-40, 0), new Vector2(40, 0));
+        fixtures.CreateFixture(groundUid, "fix1", new Fixture(horizontal, 2, 2, true), body: ground);
+
+        var vertical = new EdgeShape(new Vector2(10, 0), new Vector2(10, 10));
+        fixtures.CreateFixture(groundUid, "fix2", new Fixture(vertical, 2, 2, true), body: ground);
+
+        var xs = new[]
+        {
+            0.0f, -10.0f, -5.0f, 5.0f, 10.0f
+        };
+
+        var columnCount = 1;
+        var rowCount = 15;
+        PolygonShape shape;
+
+        for (var j = 0; j < columnCount; j++)
+        {
+            for (var i = 0; i < rowCount; i++)
+            {
+                var x = 0.0f;
+
+                var boxUid = entManager.SpawnEntity(null,
+                    new MapCoordinates(new Vector2(xs[j] + x, 0.55f + 1.1f * i), mapId));
+                var box = entManager.AddComponent<PhysicsComponent>(boxUid);
+
+                physics.SetBodyType(boxUid, BodyType.Dynamic, body: box);
+
+                shape = new PolygonShape();
+                shape.SetAsBox(0.5f, 0.5f);
+                physics.SetFixedRotation(boxUid, false, body: box);
+                fixtures.CreateFixture(boxUid, "fix1", new Fixture(shape, 2, 2, true), body: box);
+
+                physics.WakeBody(boxUid, body: box);
+                physics.SetSleepingAllowed(boxUid, box, false);
+            }
+        }
+
+        physics.WakeBody(groundUid, body: ground);
+    }
+}

Robust.Benchmarks/Physics/CircleStackBenchmark.cs

@@ -0,0 +1,92 @@
+using System.Numerics;
+using BenchmarkDotNet.Attributes;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Collision.Shapes;
+using Robust.Shared.Physics.Components;
+using Robust.Shared.Physics.Dynamics;
+using Robust.Shared.Physics.Systems;
+using Robust.UnitTesting.Server;
+
+namespace Robust.Benchmarks.Physics;
+
+[Virtual]
+public class PhysicsCircleStackBenchmark
+{
+    private ISimulation _sim = default!;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _sim = RobustServerSimulation.NewSimulation().InitializeInstance();
+
+        var entManager = _sim.Resolve<IEntityManager>();
+        entManager.System<SharedMapSystem>().CreateMap(out var mapId);
+        SetupTumbler(entManager, mapId);
+
+        for (var i = 0; i < 30; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    [Benchmark]
+    public void CircleStack()
+    {
+        var entManager = _sim.Resolve<IEntityManager>();
+
+        for (var i = 0; i < 10000; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    private void SetupTumbler(IEntityManager entManager, MapId mapId)
+    {
+        var physics = entManager.System<SharedPhysicsSystem>();
+        var fixtures = entManager.System<FixtureSystem>();
+
+        var groundUid = entManager.SpawnEntity(null, new MapCoordinates(0, 0, mapId));
+        var ground = entManager.AddComponent<PhysicsComponent>(groundUid);
+
+        var horizontal = new EdgeShape(new Vector2(-40, 0), new Vector2(40, 0));
+        fixtures.CreateFixture(groundUid, "fix1", new Fixture(horizontal, 2, 2, true), body: ground);
+
+        var vertical = new EdgeShape(new Vector2(20, 0), new Vector2(20, 20));
+        fixtures.CreateFixture(groundUid, "fix2", new Fixture(vertical, 2, 2, true), body: ground);
+
+        var xs = new[]
+        {
+            0.0f, -10.0f, -5.0f, 5.0f, 10.0f
+        };
+
+        var columnCount = 1;
+        var rowCount = 15;
+        PhysShapeCircle shape;
+
+        for (var j = 0; j < columnCount; j++)
+        {
+            for (var i = 0; i < rowCount; i++)
+            {
+                var x = 0.0f;
+
+                var boxUid = entManager.SpawnEntity(null,
+                    new MapCoordinates(new Vector2(xs[j] + x, 0.55f + 2.1f * i), mapId));
+                var box = entManager.AddComponent<PhysicsComponent>(boxUid);
+
+                physics.SetBodyType(boxUid, BodyType.Dynamic, body: box);
+                shape = new PhysShapeCircle(0.5f);
+                physics.SetFixedRotation(boxUid, false, body: box);
+                // TODO: Need to detect shape and work out if we need to use fixedrotation
+
+                fixtures.CreateFixture(boxUid, "fix1", new Fixture(shape, 2, 2, true, 5f));
+                physics.WakeBody(boxUid, body: box);
+                physics.SetSleepingAllowed(boxUid, box, false);
+            }
+        }
+
+        physics.WakeBody(groundUid, body: ground);
+    }
+}

Robust.Benchmarks/Physics/PyramidBenchmark.cs

@@ -0,0 +1,91 @@
+using System;
+using System.Numerics;
+using BenchmarkDotNet.Attributes;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Collision.Shapes;
+using Robust.Shared.Physics.Components;
+using Robust.Shared.Physics.Dynamics;
+using Robust.Shared.Physics.Systems;
+using Robust.UnitTesting.Server;
+
+namespace Robust.Benchmarks.Physics;
+
+[Virtual]
+public class PhysicsPyramidBenchmark
+{
+    private ISimulation _sim = default!;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _sim = RobustServerSimulation.NewSimulation().InitializeInstance();
+
+        var entManager = _sim.Resolve<IEntityManager>();
+        entManager.System<SharedMapSystem>().CreateMap(out var mapId);
+        SetupTumbler(entManager, mapId);
+
+        for (var i = 0; i < 300; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    [Benchmark]
+    public void Pyramid()
+    {
+        var entManager = _sim.Resolve<IEntityManager>();
+
+        for (var i = 0; i < 5000; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    private void SetupTumbler(IEntityManager entManager, MapId mapId)
+    {
+        const byte count = 20;
+
+        // Setup ground
+        var physics = entManager.System<SharedPhysicsSystem>();
+        var fixtures = entManager.System<FixtureSystem>();
+        var groundUid = entManager.SpawnEntity(null, new MapCoordinates(0, 0, mapId));
+        var ground = entManager.AddComponent<PhysicsComponent>(groundUid);
+
+        var horizontal = new EdgeShape(new Vector2(40, 0), new Vector2(-40, 0));
+        fixtures.CreateFixture(groundUid, "fix1", new Fixture(horizontal, 2, 2, true), body: ground);
+        physics.WakeBody(groundUid, body: ground);
+
+        // Setup boxes
+        float a = 0.5f;
+        PolygonShape shape = new();
+        shape.SetAsBox(a, a);
+
+        var x = new Vector2(-7.0f, 0.75f);
+        Vector2 y;
+        Vector2 deltaX = new Vector2(0.5625f, 1.25f);
+        Vector2 deltaY = new Vector2(1.125f, 0.0f);
+
+        for (var i = 0; i < count; ++i)
+        {
+            y = x;
+
+            for (var j = i; j < count; ++j)
+            {
+                var boxUid = entManager.SpawnEntity(null, new MapCoordinates(y, mapId));
+                var box = entManager.AddComponent<PhysicsComponent>(boxUid);
+                physics.SetBodyType(boxUid, BodyType.Dynamic, body: box);
+
+                fixtures.CreateFixture(boxUid, "fix1", new Fixture(shape, 2, 2, true, 5f), body: box);
+                y += deltaY;
+
+                physics.WakeBody(boxUid, body: box);
+                physics.SetSleepingAllowed(boxUid, box, false);
+            }
+
+            x += deltaX;
+        }
+    }
+}

Robust.Benchmarks/Physics/TumblerBenchmark.cs

@@ -0,0 +1,108 @@
+using System;
+using System.Numerics;
+using BenchmarkDotNet.Attributes;
+using Robust.Shared.Analyzers;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Map;
+using Robust.Shared.Physics;
+using Robust.Shared.Physics.Collision.Shapes;
+using Robust.Shared.Physics.Components;
+using Robust.Shared.Physics.Dynamics;
+using Robust.Shared.Physics.Systems;
+using Robust.UnitTesting.Server;
+
+namespace Robust.Benchmarks.Physics;
+
+[Virtual]
+public class PhysicsTumblerBenchmark
+{
+    private ISimulation _sim = default!;
+
+    [GlobalSetup]
+    public void Setup()
+    {
+        _sim = RobustServerSimulation.NewSimulation().InitializeInstance();
+
+        var entManager = _sim.Resolve<IEntityManager>();
+        var physics = entManager.System<SharedPhysicsSystem>();
+        var fixtures = entManager.System<FixtureSystem>();
+        var mapUid = entManager.System<SharedMapSystem>().CreateMap(out var mapId);
+        SetupTumbler(entManager, mapId);
+
+        for (var i = 0; i < 300; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+            var boxUid = entManager.SpawnEntity(null, new MapCoordinates(0f, 10f, mapId));
+            var box = entManager.AddComponent<PhysicsComponent>(boxUid);
+            physics.SetBodyType(boxUid, BodyType.Dynamic, body: box);
+            physics.SetFixedRotation(boxUid, false, body: box);
+            var shape = new PolygonShape();
+            shape.SetAsBox(0.125f, 0.125f);
+            fixtures.CreateFixture(boxUid, "fix1", new Fixture(shape, 2, 2, true, 0.0625f), body: box);
+            physics.WakeBody(boxUid, body: box);
+            physics.SetSleepingAllowed(boxUid, box, false);
+        }
+
+        if (entManager.TryGetComponent(mapUid, out BroadphaseComponent? mapBroadphase))
+            entManager.System<SharedBroadphaseSystem>().RebuildBottomUp(mapBroadphase);
+    }
+
+    [Benchmark]
+    public void Tumbler()
+    {
+        var entManager = _sim.Resolve<IEntityManager>();
+
+        for (var i = 0; i < 1000; i++)
+        {
+            entManager.TickUpdate(0.016f, false);
+        }
+    }
+
+    private void SetupTumbler(IEntityManager entManager, MapId mapId)
+    {
+        var physics = entManager.System<SharedPhysicsSystem>();
+        var fixtures = entManager.System<FixtureSystem>();
+        var joints = entManager.System<SharedJointSystem>();
+
+        var groundUid = entManager.SpawnEntity(null, new MapCoordinates(0f, 0f, mapId));
+        var ground = entManager.AddComponent<PhysicsComponent>(groundUid);
+        // Due to lookup changes fixtureless bodies are invalid, so
+        var cShape = new PhysShapeCircle(1f);
+        fixtures.CreateFixture(groundUid, "fix1", new Fixture(cShape, 0, 0, false));
+
+        var bodyUid = entManager.SpawnEntity(null, new MapCoordinates(0f, 10f, mapId));
+        var body = entManager.AddComponent<PhysicsComponent>(bodyUid);
+
+        physics.SetBodyType(bodyUid, BodyType.Dynamic, body: body);
+        physics.SetSleepingAllowed(bodyUid, body, false);
+        physics.SetFixedRotation(bodyUid, false, body: body);
+
+
+        // TODO: Box2D just deref, bleh shape structs someday
+        var shape1 = new PolygonShape();
+        shape1.SetAsBox(0.5f, 10.0f, new Vector2(10.0f, 0.0f), 0.0f);
+        fixtures.CreateFixture(bodyUid, "fix1", new Fixture(shape1, 2, 0, true, 20f));
+
+        var shape2 = new PolygonShape();
+        shape2.SetAsBox(0.5f, 10.0f, new Vector2(-10.0f, 0.0f), 0f);
+        fixtures.CreateFixture(bodyUid, "fix2", new Fixture(shape2, 2, 0, true, 20f));
+
+        var shape3 = new PolygonShape();
+        shape3.SetAsBox(10.0f, 0.5f, new Vector2(0.0f, 10.0f), 0f);
+        fixtures.CreateFixture(bodyUid, "fix3", new Fixture(shape3, 2, 0, true, 20f));
+
+        var shape4 = new PolygonShape();
+        shape4.SetAsBox(10.0f, 0.5f, new Vector2(0.0f, -10.0f), 0f);
+        fixtures.CreateFixture(bodyUid, "fix4", new Fixture(shape4, 2, 0, true, 20f));
+
+        physics.WakeBody(groundUid, body: ground);
+        physics.WakeBody(bodyUid, body: body);
+        var revolute = joints.CreateRevoluteJoint(groundUid, bodyUid);
+        revolute.LocalAnchorA = new Vector2(0f, 10f);
+        revolute.LocalAnchorB = new Vector2(0f, 0f);
+        revolute.ReferenceAngle = 0f;
+        revolute.MotorSpeed = 0.05f * MathF.PI;
+        revolute.MaxMotorTorque = 100000000f;
+        revolute.EnableMotor = true;
+    }
+}

Robust.Benchmarks/Robust.Benchmarks.csproj

@@ -19,6 +19,10 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" />
+
+    <!-- Needed to pin transitive dependency versions. -->
+    <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" />
+    <PackageReference Include="System.Formats.Asn1" />
   </ItemGroup>
 
   <Import Project="..\MSBuild\Robust.Properties.targets" />

Robust.Benchmarks/Transform/RecursiveMoveBenchmark.cs

@@ -42,8 +42,8 @@ public class RecursiveMoveBenchmark : RobustIntegrationTest
     public void GlobalSetup()
     {
         ProgramShared.PathOffset = "../../../../";
-        var server = StartServer();
-        var client = StartClient();
+        var server = StartServer(new() {Pool = false});
+        var client = StartClient(new() {Pool = false});
 
         Task.WhenAll(client.WaitIdleAsync(), server.WaitIdleAsync()).Wait();
 

Robust.Client.Injectors/CompileRobustXamlTask.cs

@@ -1,8 +1,8 @@
 using System;
-using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using Microsoft.Build.Framework;
+using Robust.Xaml;
 
 namespace Robust.Build.Tasks
 {
@@ -37,10 +37,12 @@ namespace Robust.Build.Tasks
             var msg = $"CompileRobustXamlTask -> AssemblyFile:{AssemblyFile}, ProjectDirectory:{ProjectDirectory}, OutputPath:{OutputPath}";
             BuildEngine.LogMessage(msg, MessageImportance.High);
 
-            var res = XamlCompiler.Compile(BuildEngine, input,
+            var res = XamlAotCompiler.Compile(
+                BuildEngine, input,
                 File.ReadAllLines(ReferencesFilePath).Where(l => !string.IsNullOrWhiteSpace(l)).ToArray(),
-                ProjectDirectory, OutputPath,
-                (SignAssembly && !DelaySign) ? AssemblyOriginatorKeyFile : null);
+                 OutputPath,
+                (SignAssembly && !DelaySign) ? AssemblyOriginatorKeyFile : null
+            );
             if (!res.success)
                 return false;
             if (!res.writtentofile)
@@ -65,22 +67,24 @@ namespace Robust.Build.Tasks
             return true;
         }
 
+        // PYREX NOTE: This project was comically null-unsafe before I touched it. I'm just marking what it did accurately
         [Required]
-        public string ReferencesFilePath { get; set; }
+        public string ReferencesFilePath { get; set; } = null!;
 
         [Required]
-        public string ProjectDirectory { get; set; }
+
+        public string ProjectDirectory { get; set; } = null!;
 
         [Required]
-        public string AssemblyFile { get; set; }
+        public string AssemblyFile { get; set; } = null!;
 
         [Required]
-        public string OriginalCopyPath { get; set; }
+        public string? OriginalCopyPath { get; set; } = null;
 
-        public string OutputPath { get; set; }
-        public string UpdateBuildIndicator { get; set; }
+        public string? OutputPath { get; set; }
+        public string UpdateBuildIndicator { get; set; } = null!;
 
-        public string AssemblyOriginatorKeyFile { get; set; }
+        public string AssemblyOriginatorKeyFile { get; set; } = null!;
         public bool SignAssembly { get; set; }
         public bool DelaySign { get; set; }
 
@@ -95,7 +99,7 @@ namespace Robust.Build.Tasks
             return rv;
         }
 
-        public IBuildEngine BuildEngine { get; set; }
-        public ITaskHost HostObject { get; set; }
+        public IBuildEngine BuildEngine { get; set; } = null!;
+        public ITaskHost HostObject { get; set; } = null!;
     }
 }

Robust.Client.Injectors/MathParsing.cs

@@ -1,37 +0,0 @@
-using System.Linq;
-using Pidgin;
-using static Pidgin.Parser;
-
-
-namespace Robust.Build.Tasks
-{
-    public static class MathParsing
-    {
-        public static Parser<char, float> Single { get; } = Real.Select(c => (float) c);
-
-        public static Parser<char, float> Single1 { get; }
-            = Single.Between(SkipWhitespaces);
-
-        public static Parser<char, (float, float)> Single2 { get; }
-            = Single.Before(SkipWhitespaces).Repeat(2).Select(e =>
-            {
-                var arr = e.ToArray();
-                return (arr[0], arr[1]);
-            });
-
-        public static Parser<char, (float, float, float, float)> Single4 { get; }
-            = Single.Before(SkipWhitespaces).Repeat(4).Select(e =>
-            {
-                var arr = e.ToArray();
-                return (arr[0], arr[1], arr[2], arr[3]);
-            });
-
-        public static Parser<char, float[]> Thickness { get; }
-            = SkipWhitespaces.Then(
-                OneOf(
-                    Try(Single4.Select(c => new[] {c.Item1, c.Item2, c.Item3, c.Item4})),
-                    Try(Single2.Select(c => new[] {c.Item1, c.Item2})),
-                    Try(Single1.Select(c => new[] {c}))
-                ));
-    }
-}

Robust.Client.Injectors/Program.cs

@@ -55,9 +55,11 @@ namespace Robust.Build.Tasks
         public bool BuildProjectFile(string projectFileName, string[] targetNames, IDictionary globalProperties,
             IDictionary targetOutputs) => throw new NotSupportedException();
 
-        public bool ContinueOnError { get; }
-        public int LineNumberOfTaskNode { get; }
-        public int ColumnNumberOfTaskNode { get; }
-        public string ProjectFileOfTaskNode { get; }
+        // PYREX NOTE: This project was extremely null-unsafe before I touched it. I'm just marking what it did already
+        // Here's the broken interface of IBuildEngine that we started with
+        public bool ContinueOnError => default;
+        public int LineNumberOfTaskNode => default;
+        public int ColumnNumberOfTaskNode => default;
+        public string ProjectFileOfTaskNode => null!;
     }
 }

Robust.Client.Injectors/Robust.Client.Injectors.csproj

@@ -1,17 +1,30 @@
 <Project Sdk="Microsoft.NET.Sdk">
+    <Import Project="..\MSBuild\Robust.Engine.props" />
 
+    <!--
+    PJB3005 (2024-08-24)
+    So the reason that Robust.Client.Injectors is NS2.0 is that Visual Studio 
+    still ships a .NET FX based MSBuild for some godforsaken reason. This means 
+    that when having Robust.Client.Injectors loaded directly by the main MSBuild 
+    process... that would break.
+
+    Except we don't do that anyways right now due to file locking issues, so maybe 
+    it's fine to give up on that. Whatever. 
+    -->
     <PropertyGroup>
-        <TargetFramework>netstandard2.0</TargetFramework>
-        <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+      <TargetFramework>netstandard2.0</TargetFramework>
+      <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
+      <LangVersion>8.0</LangVersion>
+      <Nullable>enable</Nullable>
     </PropertyGroup>
 
     <ItemGroup>
       <PackageReference Include="Microsoft.Build.Framework" Version="17.8.3" />
       <PackageReference Include="Mono.Cecil" Version="0.11.5" />
-      <PackageReference Include="Pidgin" Version="2.5.0" />
     </ItemGroup>
 
     <ItemGroup>
       <ProjectReference Include="..\XamlX\src\XamlX.IL.Cecil\XamlX.IL.Cecil.csproj" />
+      <ProjectReference Include="..\Robust.Xaml\Robust.Xaml.csproj" />
     </ItemGroup>
 </Project>

Robust.Client.Injectors/XamlCompiler.cs

@@ -1,388 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
-using Microsoft.Build.Framework;
-using Mono.Cecil;
-using Mono.Cecil.Cil;
-using Mono.Cecil.Rocks;
-using Pidgin;
-using XamlX;
-using XamlX.Ast;
-using XamlX.Emit;
-using XamlX.IL;
-using XamlX.Parsers;
-using XamlX.Transform;
-using XamlX.TypeSystem;
-
-namespace Robust.Build.Tasks
-{
-    /// <summary>
-    /// Based on https://github.com/AvaloniaUI/Avalonia/blob/c85fa2b9977d251a31886c2534613b4730fbaeaf/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
-    /// Adjusted for our UI-Framework
-    /// </summary>
-    public partial class XamlCompiler
-    {
-        public static (bool success, bool writtentofile) Compile(IBuildEngine engine, string input, string[] references,
-            string projectDirectory, string output, string strongNameKey)
-        {
-            var typeSystem = new CecilTypeSystem(references
-                .Where(r => !r.ToLowerInvariant().EndsWith("robust.build.tasks.dll"))
-                .Concat(new[] { input }), input);
-
-            var asm = typeSystem.TargetAssemblyDefinition;
-
-            if (asm.MainModule.GetType("CompiledRobustXaml", "XamlIlContext") != null)
-            {
-                // If this type exists, the assembly has already been processed by us.
-                // Do not run again, it would corrupt the file.
-                // This *shouldn't* be possible due to Inputs/Outputs dependencies in the build system,
-                // but better safe than sorry eh?
-                engine.LogWarningEvent(new BuildWarningEventArgs("XAMLIL", "", "", 0, 0, 0, 0, "Ran twice on same assembly file; ignoring.", "", ""));
-                return (true, false);
-            }
-
-            var compileRes = CompileCore(engine, typeSystem);
-            if (compileRes == null)
-                return (true, false);
-            if (compileRes == false)
-                return (false, false);
-
-            var writerParameters = new WriterParameters { WriteSymbols = asm.MainModule.HasSymbols };
-            if (!string.IsNullOrWhiteSpace(strongNameKey))
-                writerParameters.StrongNameKeyBlob = File.ReadAllBytes(strongNameKey);
-
-            asm.Write(output, writerParameters);
-
-            return (true, true);
-
-        }
-
-        static bool? CompileCore(IBuildEngine engine, CecilTypeSystem typeSystem)
-        {
-            var asm = typeSystem.TargetAssemblyDefinition;
-            var embrsc = new EmbeddedResources(asm);
-
-            if (embrsc.Resources.Count(CheckXamlName) == 0)
-                // Nothing to do
-                return null;
-
-            var xamlLanguage = new XamlLanguageTypeMappings(typeSystem)
-            {
-                XmlnsAttributes =
-                {
-                    typeSystem.GetType("Avalonia.Metadata.XmlnsDefinitionAttribute"),
-
-                },
-                ContentAttributes =
-                {
-                    typeSystem.GetType("Avalonia.Metadata.ContentAttribute")
-                },
-                UsableDuringInitializationAttributes =
-                {
-                    typeSystem.GetType("Robust.Client.UserInterface.XAML.UsableDuringInitializationAttribute")
-                },
-                DeferredContentPropertyAttributes =
-                {
-                    typeSystem.GetType("Robust.Client.UserInterface.XAML.DeferredContentAttribute")
-                },
-                RootObjectProvider = typeSystem.GetType("Robust.Client.UserInterface.XAML.ITestRootObjectProvider"),
-                UriContextProvider = typeSystem.GetType("Robust.Client.UserInterface.XAML.ITestUriContext"),
-                ProvideValueTarget = typeSystem.GetType("Robust.Client.UserInterface.XAML.ITestProvideValueTarget"),
-            };
-            var emitConfig = new XamlLanguageEmitMappings<IXamlILEmitter, XamlILNodeEmitResult>
-            {
-                ContextTypeBuilderCallback = (b,c) => EmitNameScopeField(xamlLanguage, typeSystem, b, c)
-            };
-
-            var transformerconfig = new TransformerConfiguration(
-                typeSystem,
-                typeSystem.TargetAssembly,
-                xamlLanguage,
-                XamlXmlnsMappings.Resolve(typeSystem, xamlLanguage), CustomValueConverter);
-
-            var contextDef = new TypeDefinition("CompiledRobustXaml", "XamlIlContext",
-                TypeAttributes.Class, asm.MainModule.TypeSystem.Object);
-            asm.MainModule.Types.Add(contextDef);
-            var contextClass = XamlILContextDefinition.GenerateContextClass(typeSystem.CreateTypeBuilder(contextDef), typeSystem,
-                xamlLanguage, emitConfig);
-
-            var compiler =
-                new RobustXamlILCompiler(transformerconfig, emitConfig, true);
-
-            bool CompileGroup(IResourceGroup group)
-            {
-                var typeDef = new TypeDefinition("CompiledRobustXaml", "!" + group.Name, TypeAttributes.Class,
-                    asm.MainModule.TypeSystem.Object);
-
-                //typeDef.CustomAttributes.Add(new CustomAttribute(ed));
-                asm.MainModule.Types.Add(typeDef);
-                var builder = typeSystem.CreateTypeBuilder(typeDef);
-
-                foreach (var res in group.Resources.Where(CheckXamlName))
-                {
-                    try
-                    {
-                        engine.LogMessage($"XAMLIL: {res.Name} -> {res.Uri}", MessageImportance.Low);
-
-                        var xaml = new StreamReader(new MemoryStream(res.FileContents)).ReadToEnd();
-                        var parsed = XDocumentXamlParser.Parse(xaml);
-
-                        var initialRoot = (XamlAstObjectNode) parsed.Root;
-
-                        var classDirective = initialRoot.Children.OfType<XamlAstXmlDirective>()
-                            .FirstOrDefault(d => d.Namespace == XamlNamespaces.Xaml2006 && d.Name == "Class");
-                        string classname;
-                        if (classDirective != null && classDirective.Values[0] is XamlAstTextNode tn)
-                        {
-                            classname = tn.Text;
-                        }
-                        else
-                        {
-                            classname = res.Name.Replace(".xaml","");
-                        }
-
-                        var classType = typeSystem.TargetAssembly.FindType(classname);
-                        if (classType == null)
-                            throw new Exception($"Unable to find type '{classname}'");
-
-                        compiler.Transform(parsed);
-
-                        var populateName = $"Populate:{res.Name}";
-                        var buildName = $"Build:{res.Name}";
-
-                        var classTypeDefinition = typeSystem.GetTypeReference(classType).Resolve();
-
-                        var populateBuilder = typeSystem.CreateTypeBuilder(classTypeDefinition);
-
-                        compiler.Compile(parsed, contextClass,
-                            compiler.DefinePopulateMethod(populateBuilder, parsed, populateName,
-                                classTypeDefinition == null),
-                            compiler.DefineBuildMethod(builder, parsed, buildName, true),
-                            null,
-                            (closureName, closureBaseType) =>
-                                populateBuilder.DefineSubType(closureBaseType, closureName, false),
-                            res.Uri, res
-                        );
-
-                        //add compiled populate method
-                        var compiledPopulateMethod = typeSystem.GetTypeReference(populateBuilder).Resolve().Methods
-                            .First(m => m.Name == populateName);
-
-                        const string TrampolineName = "!XamlIlPopulateTrampoline";
-                        var trampoline = new MethodDefinition(TrampolineName,
-                            MethodAttributes.Static | MethodAttributes.Private, asm.MainModule.TypeSystem.Void);
-                        trampoline.Parameters.Add(new ParameterDefinition(classTypeDefinition));
-                        classTypeDefinition.Methods.Add(trampoline);
-
-                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Ldnull));
-                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Ldarg_0));
-                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Call, compiledPopulateMethod));
-                        trampoline.Body.Instructions.Add(Instruction.Create(OpCodes.Ret));
-
-                        var foundXamlLoader = false;
-                        // Find RobustXamlLoader.Load(this) and replace it with !XamlIlPopulateTrampoline(this)
-                        foreach (var method in classTypeDefinition.Methods
-                            .Where(m => !m.Attributes.HasFlag(MethodAttributes.Static)))
-                        {
-                            var i = method.Body.Instructions;
-                            for (var c = 1; c < i.Count; c++)
-                            {
-                                if (i[c].OpCode == OpCodes.Call)
-                                {
-                                    var op = i[c].Operand as MethodReference;
-
-                                    if (op != null
-                                        && op.Name == TrampolineName)
-                                    {
-                                        foundXamlLoader = true;
-                                        break;
-                                    }
-
-                                    if (op != null
-                                        && op.Name == "Load"
-                                        && op.Parameters.Count == 1
-                                        && op.Parameters[0].ParameterType.FullName == "System.Object"
-                                        && op.DeclaringType.FullName == "Robust.Client.UserInterface.XAML.RobustXamlLoader")
-                                    {
-                                        if (MatchThisCall(i, c - 1))
-                                        {
-                                            i[c].Operand = trampoline;
-                                            foundXamlLoader = true;
-                                        }
-                                    }
-                                }
-                            }
-                        }
-
-                        if (!foundXamlLoader)
-                        {
-                            var ctors = classTypeDefinition.GetConstructors()
-                                .Where(c => !c.IsStatic).ToList();
-                            // We can inject xaml loader into default constructor
-                            if (ctors.Count == 1 && ctors[0].Body.Instructions.Count(o=>o.OpCode != OpCodes.Nop) == 3)
-                            {
-                                var i = ctors[0].Body.Instructions;
-                                var retIdx = i.IndexOf(i.Last(x => x.OpCode == OpCodes.Ret));
-                                i.Insert(retIdx, Instruction.Create(OpCodes.Call, trampoline));
-                                i.Insert(retIdx, Instruction.Create(OpCodes.Ldarg_0));
-                            }
-                            else
-                            {
-                                throw new InvalidProgramException(
-                                    $"No call to RobustXamlLoader.Load(this) call found anywhere in the type {classType.FullName} and type seems to have custom constructors.");
-                            }
-                        }
-                    }
-                    catch (Exception e)
-                    {
-                        engine.LogErrorEvent(new BuildErrorEventArgs("XAMLIL", "", res.FilePath, 0, 0, 0, 0,
-                            $"{res.FilePath}: {e.Message}", "", "CompileRobustXaml"));
-                    }
-                }
-                return true;
-            }
-
-            if (embrsc.Resources.Count(CheckXamlName) != 0)
-            {
-                if (!CompileGroup(embrsc))
-                    return false;
-            }
-
-            return true;
-        }
-
-        private static bool CustomValueConverter(
-            AstTransformationContext context,
-            IXamlAstValueNode node,
-            IXamlType type,
-            out IXamlAstValueNode result)
-        {
-            if (!(node is XamlAstTextNode textNode))
-            {
-                result = null;
-                return false;
-            }
-
-            var text = textNode.Text;
-            var types = context.GetRobustTypes();
-
-            if (type.Equals(types.Vector2))
-            {
-                var foo = MathParsing.Single2.Parse(text);
-
-                if (!foo.Success)
-                    throw new XamlLoadException($"Unable to parse \"{text}\" as a Vector2", node);
-
-                var (x, y) = foo.Value;
-
-                result = new RXamlSingleVecLikeConstAstNode(
-                    node,
-                    types.Vector2, types.Vector2ConstructorFull,
-                    types.Single, new[] {x, y});
-                return true;
-            }
-
-            if (type.Equals(types.Thickness))
-            {
-                var foo = MathParsing.Thickness.Parse(text);
-
-                if (!foo.Success)
-                    throw new XamlLoadException($"Unable to parse \"{text}\" as a Thickness", node);
-
-                var val = foo.Value;
-                float[] full;
-                if (val.Length == 1)
-                {
-                    var u = val[0];
-                    full = new[] {u, u, u, u};
-                }
-                else if (val.Length == 2)
-                {
-                    var h = val[0];
-                    var v = val[1];
-                    full = new[] {h, v, h, v};
-                }
-                else // 4
-                {
-                    full = val;
-                }
-
-                result = new RXamlSingleVecLikeConstAstNode(
-                    node,
-                    types.Thickness, types.ThicknessConstructorFull,
-                    types.Single, full);
-                return true;
-            }
-
-            if (type.Equals(types.Thickness))
-            {
-                var foo = MathParsing.Thickness.Parse(text);
-
-                if (!foo.Success)
-                    throw new XamlLoadException($"Unable to parse \"{text}\" as a Thickness", node);
-
-                var val = foo.Value;
-                float[] full;
-                if (val.Length == 1)
-                {
-                    var u = val[0];
-                    full = new[] {u, u, u, u};
-                }
-                else if (val.Length == 2)
-                {
-                    var h = val[0];
-                    var v = val[1];
-                    full = new[] {h, v, h, v};
-                }
-                else // 4
-                {
-                    full = val;
-                }
-
-                result = new RXamlSingleVecLikeConstAstNode(
-                    node,
-                    types.Thickness, types.ThicknessConstructorFull,
-                    types.Single, full);
-                return true;
-            }
-
-            if (type.Equals(types.Color))
-            {
-                // TODO: Interpret these colors at XAML compile time instead of at runtime.
-                result = new RXamlColorAstNode(node, types, text);
-                return true;
-            }
-
-            result = null;
-            return false;
-        }
-
-        public const string ContextNameScopeFieldName = "RobustNameScope";
-
-        private static void EmitNameScopeField(XamlLanguageTypeMappings xamlLanguage, CecilTypeSystem typeSystem, IXamlTypeBuilder<IXamlILEmitter> typeBuilder, IXamlILEmitter constructor)
-        {
-            var nameScopeType = typeSystem.FindType("Robust.Client.UserInterface.XAML.NameScope");
-            var field = typeBuilder.DefineField(nameScopeType,
-                ContextNameScopeFieldName, true, false);
-            constructor
-                .Ldarg_0()
-                .Newobj(nameScopeType.GetConstructor())
-                .Stfld(field);
-        }
-    }
-
-    interface IResource : IFileSource
-    {
-        string Uri { get; }
-        string Name { get; }
-        void Remove();
-
-    }
-
-    interface IResourceGroup
-    {
-        string Name { get; }
-        IEnumerable<IResource> Resources { get; }
-    }
-}

Robust.Client.NameGenerator/XamlUiPartialClassGenerator.cs

@@ -15,6 +15,9 @@ using XamlX.Transform;
 using XamlX.Transform.Transformers;
 using XamlX.TypeSystem;
 
+// Yes dude I know this source generator isn't incremental, I'll fix it eventually.
+#pragma warning disable RS1035
+
 namespace Robust.Client.NameGenerator
 {
     /// <summary>

Robust.Client.WebView/Cef/BaseRobustCefClient.cs

@@ -64,6 +64,8 @@ internal abstract class BaseRobustCefClient : CefClient
             string title,
             string defaultFilePath,
             string[] acceptFilters,
+            string[] acceptExtensions,
+            string[] acceptDescriptions,
             CefFileDialogCallback callback)
         {
             callback.Cancel();

Robust.Client.WebView/Cef/Program.cs

@@ -6,7 +6,7 @@ using Xilium.CefGlue;
 
 namespace Robust.Client.WebView.Cef
 {
-    public static class Program
+    internal static class Program
     {
         // This was supposed to be the main entry for the subprocess program... It doesn't work.
         public static int Main(string[] args)

Robust.Client.WebView/Cef/RobustCefApp.cs

@@ -44,6 +44,8 @@ namespace Robust.Client.WebView.Cef
             //commandLine.AppendSwitch("--disable-gpu-compositing");
             //commandLine.AppendSwitch("--in-process-gpu");
 
+            commandLine.AppendSwitch("--off-screen-rendering-enabled");
+
             commandLine.AppendSwitch("disable-threaded-scrolling", "1");
             commandLine.AppendSwitch("disable-features", "TouchpadAndWheelScrollLatching,AsyncWheelEvents");
 

Robust.Client.WebView/Cef/WebViewManagerCef.BrowserWindow.cs

@@ -23,6 +23,7 @@ namespace Robust.Client.WebView.Cef
             var info = CefWindowInfo.Create();
             info.Bounds = new CefRectangle(0, 0, createParams.Width, createParams.Height);
             info.SetAsPopup(mainHWnd, "ss14cef");
+             info.RuntimeStyle = CefRuntimeStyle.Alloy;
 
             var impl = new WebViewWindowImpl(this);
 

Robust.Client.WebView/Cef/WebViewManagerCef.Control.cs

@@ -162,9 +162,10 @@ namespace Robust.Client.WebView.Cef
                 }
             }
 
+            public bool IsOpen => _data != null;
             public bool IsLoading => _data?.Browser.IsLoading ?? false;
 
-            public void EnteredTree()
+            public void StartBrowser()
             {
                 DebugTools.AssertNull(_data);
 
@@ -195,7 +196,7 @@ namespace Robust.Client.WebView.Cef
                 _data = new LiveData(texture, client, browser, renderer);
             }
 
-            public void ExitedTree()
+            public void CloseBrowser()
             {
                 DebugTools.AssertNotNull(_data);
 
@@ -484,27 +485,27 @@ namespace Robust.Client.WebView.Cef
             public void FocusEntered()
             {
                 if (_textInputActive)
-                    _clyde.TextInputStart();
+                    Owner.Root?.Window?.TextInputStart();
             }
 
             public void FocusExited()
             {
                 if (_textInputActive)
-                    _clyde.TextInputStop();
+                    Owner.Root?.Window?.TextInputStop();
             }
 
             public void TextInputStart()
             {
                 _textInputActive = true;
                 if (Owner.HasKeyboardFocus())
-                    _clyde.TextInputStart();
+                    Owner.Root?.Window?.TextInputStart();
             }
 
             public void TextInputStop()
             {
                 _textInputActive = false;
                 if (Owner.HasKeyboardFocus())
-                    _clyde.TextInputStop();
+                    Owner.Root?.Window?.TextInputStop();
             }
 
             private sealed class LiveData
@@ -587,8 +588,11 @@ namespace Robust.Client.WebView.Cef
                 }
             }
 
-            protected override void OnAcceleratedPaint(CefBrowser browser, CefPaintElementType type,
-                CefRectangle[] dirtyRects, IntPtr sharedHandle)
+            protected override void OnAcceleratedPaint(
+                CefBrowser browser,
+                CefPaintElementType type,
+                CefRectangle[] dirtyRects,
+                in CefAcceleratedPaintInfo info)
             {
                 // Unused, but we're forced to implement it so.. NOOP.
             }

Robust.Client.WebView/Cef/WebViewManagerCef.cs

@@ -5,6 +5,7 @@ using System.Net;
 using System.Reflection;
 using System.Text;
 using Robust.Client.Console;
+using Robust.Client.Utility;
 using Robust.Shared.Configuration;
 using Robust.Shared.ContentPack;
 using Robust.Shared.IoC;
@@ -24,6 +25,7 @@ namespace Robust.Client.WebView.Cef
 
         [Dependency] private readonly IDependencyCollection _dependencyCollection = default!;
         [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+        [Dependency] private readonly IGameControllerInternal _gameController = default!;
         [Dependency] private readonly IResourceManagerInternal _resourceManager = default!;
         [Dependency] private readonly IClientConsoleHost _consoleHost = default!;
         [Dependency] private readonly IConfigurationManager _cfg = default!;
@@ -61,7 +63,10 @@ namespace Robust.Client.WebView.Cef
 
             var cachePath = "";
             if (_resourceManager.UserData is WritableDirProvider userData)
-                cachePath = userData.GetFullPath(new ResPath("/cef_cache"));
+            {
+                var rootDir = UserDataDir.GetRootUserDataDir(_gameController);
+                cachePath = Path.Combine(rootDir, "cef_cache", "0");
+            }
 
             var settings = new CefSettings()
             {

Robust.Client.WebView/Headless/WebViewManagerHeadless.cs

@@ -81,11 +81,13 @@ namespace Robust.Client.WebView.Headless
 
         private sealed class WebViewControlImplDummy : DummyBase, IWebViewControlImpl
         {
-            public void EnteredTree()
+            public bool IsOpen => false;
+
+            public void StartBrowser()
             {
             }
 
-            public void ExitedTree()
+            public void CloseBrowser()
             {
             }
 

Robust.Client.WebView/IWebViewControlImpl.cs

@@ -9,8 +9,10 @@ namespace Robust.Client.WebView
     /// </summary>
     internal interface IWebViewControlImpl : IWebViewControl
     {
-        void EnteredTree();
-        void ExitedTree();
+        public bool IsOpen { get; }
+
+        void StartBrowser();
+        void CloseBrowser();
         void MouseMove(GUIMouseMoveEventArgs args);
         void MouseExited();
         void MouseWheel(GUIMouseWheelEventArgs args);

Robust.Client.WebView/Robust.Client.WebView.csproj

@@ -5,6 +5,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <OutputType>WinExe</OutputType>
     <ValidateExecutableReferencesMatchSelfContained>false</ValidateExecutableReferencesMatchSelfContained>
+    <CETCompat>false</CETCompat>
   </PropertyGroup>
 
   <ItemGroup>

Robust.Client.WebView/WebViewControl.cs

@@ -14,6 +14,7 @@ namespace Robust.Client.WebView
         [Dependency] private readonly IWebViewManagerInternal _webViewManager = default!;
 
         private readonly IWebViewControlImpl _controlImpl;
+        private bool _alwaysActive;
 
         [ViewVariables(VVAccess.ReadWrite)]
         public string Url
@@ -22,6 +23,21 @@ namespace Robust.Client.WebView
             set => _controlImpl.Url = value;
         }
 
+        [ViewVariables(VVAccess.ReadWrite)]
+        public bool AlwaysActive
+        {
+            get => _alwaysActive;
+            set
+            {
+                _alwaysActive = value;
+
+                if (_alwaysActive && !_controlImpl.IsOpen)
+                    _controlImpl.StartBrowser();
+                else if (!_alwaysActive && _controlImpl.IsOpen && !IsInsideTree)
+                    _controlImpl.CloseBrowser();
+            }
+        }
+
         [ViewVariables] public bool IsLoading => _controlImpl.IsLoading;
 
         public WebViewControl()
@@ -39,14 +55,16 @@ namespace Robust.Client.WebView
         {
             base.EnteredTree();
 
-            _controlImpl.EnteredTree();
+            if (!_controlImpl.IsOpen)
+                _controlImpl.StartBrowser();
         }
 
         protected override void ExitedTree()
         {
             base.ExitedTree();
 
-            _controlImpl.ExitedTree();
+            if (!_alwaysActive)
+                _controlImpl.CloseBrowser();
         }
 
         protected internal override void MouseMove(GUIMouseMoveEventArgs args)

Robust.Client/Animations/AnimationTrackPlaySound.cs

@@ -40,11 +40,7 @@ namespace Robust.Client.Animations
                 var keyFrame = KeyFrames[keyFrameIndex];
 
                 var audioParams = keyFrame.AudioParamsFunc.Invoke();
-                var audio = new SoundPathSpecifier(keyFrame.Resource)
-                {
-                    Params = audioParams
-                };
-                IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<AudioSystem>().PlayEntity(audio, Filter.Local(), entity, true);
+                IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<AudioSystem>().PlayEntity(keyFrame.Specifier, Filter.Local(), entity, true, audioParams);
             }
 
             return (keyFrameIndex, playingTime);
@@ -55,7 +51,7 @@ namespace Robust.Client.Animations
             /// <summary>
             ///     The RSI state to play when this keyframe gets triggered.
             /// </summary>
-            public readonly string Resource;
+            public readonly ResolvedSoundSpecifier Specifier;
 
             /// <summary>
             ///     A function that returns the audio parameter to be used.
@@ -69,9 +65,9 @@ namespace Robust.Client.Animations
             /// </summary>
             public readonly float KeyTime;
 
-            public KeyFrame(string resource, float keyTime, Func<AudioParams>? audioParams = null)
+            public KeyFrame(ResolvedSoundSpecifier specifier, float keyTime, Func<AudioParams>? audioParams = null)
             {
-                Resource = resource;
+                Specifier = specifier;
                 KeyTime = keyTime;
                 AudioParamsFunc = audioParams ?? (() => AudioParams.Default);
             }

Robust.Client/Animations/AnimationTrackProperty.cs

@@ -13,7 +13,7 @@ namespace Robust.Client.Animations
     /// </summary>
     public abstract class AnimationTrackProperty : AnimationTrack
     {
-        public List<KeyFrame> KeyFrames { get; protected set; } = new();
+        public List<KeyFrame> KeyFrames { get; set; } = new();
 
         /// <summary>
         ///     How to interpolate values when between two keyframes.

Robust.Client/Audio/AudioManager.Public.cs

@@ -84,6 +84,19 @@ internal partial class AudioManager
         AL.Listener(ALListenerfv.Orientation, ref at, ref up);
     }
 
+    void IAudioInternal.Remove(AudioStream stream)
+    {
+        if (stream.ClydeHandle == null)
+            return;
+
+        if (!_audioSampleBuffers.Remove(stream.BufferId))
+        {
+            return;
+        }
+
+        AL.DeleteBuffer(stream.BufferId);
+    }
+
     /// <inheritdoc/>
     public AudioStream LoadAudioOggVorbis(Stream stream, string? name = null)
     {
@@ -120,9 +133,9 @@ internal partial class AudioManager
         _checkAlError();
 
         var handle = new ClydeHandle(_audioSampleBuffers.Count);
-        _audioSampleBuffers.Add(new LoadedAudioSample(buffer));
+        _audioSampleBuffers.Add(buffer, new LoadedAudioSample(buffer));
         var length = TimeSpan.FromSeconds(vorbis.TotalSamples / (double) vorbis.SampleRate);
-        return new AudioStream(handle, length, (int) vorbis.Channels, name, vorbis.Title, vorbis.Artist);
+        return new AudioStream(this, buffer, handle, length, (int) vorbis.Channels, name, vorbis.Title, vorbis.Artist);
     }
 
     /// <inheritdoc/>
@@ -179,9 +192,9 @@ internal partial class AudioManager
         _checkAlError();
 
         var handle = new ClydeHandle(_audioSampleBuffers.Count);
-        _audioSampleBuffers.Add(new LoadedAudioSample(buffer));
+        _audioSampleBuffers.Add(buffer, new LoadedAudioSample(buffer));
         var length = TimeSpan.FromSeconds(wav.Data.Length / (double) wav.BlockAlign / wav.SampleRate);
-        return new AudioStream(handle, length, wav.NumChannels, name);
+        return new AudioStream(this, buffer, handle, length, wav.NumChannels, name);
     }
 
     /// <inheritdoc/>
@@ -210,8 +223,8 @@ internal partial class AudioManager
 
         var handle = new ClydeHandle(_audioSampleBuffers.Count);
         var length = TimeSpan.FromSeconds((double) samples.Length / channels / sampleRate);
-        _audioSampleBuffers.Add(new LoadedAudioSample(buffer));
-        return new AudioStream(handle, length, channels, name);
+        _audioSampleBuffers.Add(buffer, new LoadedAudioSample(buffer));
+        return new AudioStream(this, buffer, handle, length, channels, name);
     }
 
     public void SetMasterGain(float newGain)
@@ -293,7 +306,7 @@ internal partial class AudioManager
 
         // ReSharper disable once PossibleInvalidOperationException
         // TODO: This really shouldn't be indexing based on the ClydeHandle...
-        AL.Source(source, ALSourcei.Buffer, _audioSampleBuffers[(int) stream.ClydeHandle!.Value].BufferHandle);
+        AL.Source(source, ALSourcei.Buffer, _audioSampleBuffers[stream.BufferId].BufferHandle);
 
         var audioSource = new AudioSource(this, source, stream);
         _audioSources.Add(source, new WeakReference<BaseAudioSource>(audioSource));
@@ -302,7 +315,7 @@ internal partial class AudioManager
     }
 
     /// <inheritdoc/>
-    IBufferedAudioSource? IAudioInternal.CreateBufferedAudioSource(int buffers, bool floatAudio=false)
+    IBufferedAudioSource? IAudioInternal.CreateBufferedAudioSource(int buffers, bool floatAudio)
     {
         var source = AL.GenSource();
 
@@ -370,5 +383,12 @@ internal partial class AudioManager
         }
 
         _bufferedAudioSources.Clear();
+
+        foreach (var buffer in _audioSampleBuffers.Values)
+        {
+            DeleteAudioBufferOnMainThread(buffer.BufferHandle);
+        }
+
+        _audioSampleBuffers.Clear();
     }
 }

Robust.Client/Audio/AudioManager.cs

@@ -5,6 +5,7 @@ using System.Threading;
 using OpenTK.Audio.OpenAL;
 using OpenTK.Audio.OpenAL.Extensions.Creative.EFX;
 using Robust.Client.Audio.Sources;
+using Robust.Client.ResourceManagement;
 using Robust.Shared;
 using Robust.Shared.Audio;
 using Robust.Shared.Configuration;
@@ -17,13 +18,15 @@ internal sealed partial class AudioManager : IAudioInternal
 {
     [Shared.IoC.Dependency] private readonly IConfigurationManager _cfg = default!;
     [Shared.IoC.Dependency] private readonly ILogManager _logMan = default!;
+    [Shared.IoC.Dependency] private readonly IReloadManager _reload = default!;
+    [Shared.IoC.Dependency] private readonly IResourceCache _cache = default!;
 
     private Thread? _gameThread;
 
     private ALDevice _openALDevice;
     private ALContext _openALContext;
 
-    private readonly List<LoadedAudioSample> _audioSampleBuffers = new();
+    private readonly Dictionary<int, LoadedAudioSample> _audioSampleBuffers = new();
 
     private readonly Dictionary<int, WeakReference<BaseAudioSource>> _audioSources =
         new();
@@ -54,8 +57,8 @@ internal sealed partial class AudioManager : IAudioInternal
         _checkAlError();
 
         // Load up AL context extensions.
-        var s = ALC.GetString(ALDevice.Null, AlcGetString.Extensions) ?? "";
-        foreach (var extension in s.Split(' '))
+        var s = ALC.GetString(_openALDevice, AlcGetString.Extensions) ?? "";
+        foreach (var extension in s.Split(' ', StringSplitOptions.RemoveEmptyEntries))
         {
             _alContextExtensions.Add(extension);
         }
@@ -116,6 +119,22 @@ internal sealed partial class AudioManager : IAudioInternal
         IsEfxSupported = HasAlDeviceExtension("ALC_EXT_EFX");
 
         _cfg.OnValueChanged(CVars.AudioMasterVolume, SetMasterGain, true);
+
+        _reload.Register("/Audio", "*.ogg");
+        _reload.Register("/Audio", "*.wav");
+
+        _reload.OnChanged += OnReload;
+    }
+
+    private void OnReload(ResPath args)
+    {
+        if (args.Extension != "ogg" &&
+            args.Extension != "wav")
+        {
+            return;
+        }
+
+        _cache.ReloadResource<AudioResource>(args);
     }
 
     internal bool IsMainThread()
@@ -140,15 +159,19 @@ internal sealed partial class AudioManager : IAudioInternal
         }
     }
 
+    internal void LogError(string message)
+    {
+        OpenALSawmill.Error(message);
+    }
+
     /// <summary>
     /// Like _checkAlError but allows custom data to be passed in as relevant.
     /// </summary>
-    internal void LogALError(string message, [CallerMemberName] string callerMember = "", [CallerLineNumber] int callerLineNumber = -1)
+    internal void LogALError(ALErrorInterpolatedStringHandler message, [CallerMemberName] string callerMember = "", [CallerLineNumber] int callerLineNumber = -1)
     {
-        var error = AL.GetError();
-        if (error != ALError.NoError)
+        if (message.Error != ALError.NoError)
         {
-            OpenALSawmill.Error("[{0}:{1}] AL error: {2}, {3}. Stacktrace is {4}", callerMember, callerLineNumber, error, message, Environment.StackTrace);
+            OpenALSawmill.Error("[{0}:{1}] AL error: {2}, {3}. Stacktrace is {4}", callerMember, callerLineNumber, message.Error, message.ToStringAndClear(), Environment.StackTrace);
         }
     }
 
@@ -170,4 +193,32 @@ internal sealed partial class AudioManager : IAudioInternal
             BufferHandle = bufferHandle;
         }
     }
+
+    [InterpolatedStringHandler]
+    internal ref struct ALErrorInterpolatedStringHandler
+    {
+        private DefaultInterpolatedStringHandler _handler;
+        public ALError Error;
+
+        public ALErrorInterpolatedStringHandler(int literalLength, int formattedCount, out bool shouldAppend)
+        {
+            Error = AL.GetError();
+            if (Error == ALError.NoError)
+            {
+                shouldAppend = false;
+                _handler = default;
+            }
+            else
+            {
+                shouldAppend = true;
+                _handler = new DefaultInterpolatedStringHandler(literalLength, formattedCount);
+            }
+        }
+
+        public string ToStringAndClear() => _handler.ToStringAndClear();
+        public override string ToString() => _handler.ToString();
+        public void AppendLiteral(string value) => _handler.AppendLiteral(value);
+        public void AppendFormatted<T>(T value) => _handler.AppendFormatted(value);
+        public void AppendFormatted<T>(T value, string? format) => _handler.AppendFormatted(value, format);
+    }
 }

Robust.Client/Audio/AudioOverlay.cs

@@ -46,7 +46,7 @@ public sealed class AudioOverlay : Overlay
 
         var screenHandle = args.ScreenHandle;
         var output = new StringBuilder();
-        var listenerPos = _entManager.GetComponent<TransformComponent>(localPlayer.Value).MapPosition;
+        var listenerPos = _transform.GetMapCoordinates(_entManager.GetComponent<TransformComponent>(localPlayer.Value));
 
         if (listenerPos.MapId != args.MapId)
             return;

Robust.Client/Audio/AudioStream.cs

@@ -6,8 +6,15 @@ namespace Robust.Client.Audio;
 /// <summary>
 /// Has the metadata for a particular audio stream as well as the relevant internal handle to it.
 /// </summary>
-public sealed class AudioStream
+public sealed class AudioStream : IDisposable
 {
+    private IAudioInternal _audio;
+
+    /// <summary>
+    /// Buffer ID for this audio in AL.
+    /// </summary>
+    internal int BufferId { get; }
+
     public TimeSpan Length { get; }
     internal IClydeHandle? ClydeHandle { get; }
     public string? Name { get; }
@@ -15,8 +22,10 @@ public sealed class AudioStream
     public string? Artist { get; }
     public int ChannelCount { get; }
 
-    internal AudioStream(IClydeHandle? handle, TimeSpan length, int channelCount, string? name = null, string? title = null, string? artist = null)
+    internal AudioStream(IAudioInternal internalAudio, int bufferId, IClydeHandle? handle, TimeSpan length, int channelCount, string? name = null, string? title = null, string? artist = null)
     {
+        _audio = internalAudio;
+        BufferId = bufferId;
         ClydeHandle = handle;
         Length = length;
         ChannelCount = channelCount;
@@ -24,4 +33,9 @@ public sealed class AudioStream
         Title = title;
         Artist = artist;
     }
+
+    public void Dispose()
+    {
+        _audio.Remove(this);
+    }
 }

Robust.Client/Audio/AudioSystem.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Numerics;
+using OpenTK.Audio.OpenAL;
 using Robust.Client.GameObjects;
 using Robust.Client.Graphics;
 using Robust.Client.Player;
@@ -37,11 +38,10 @@ public sealed partial class AudioSystem : SharedAudioSystem
     [Dependency] private readonly IReplayRecordingManager _replayRecording = default!;
     [Dependency] private readonly IEyeManager _eyeManager = default!;
     [Dependency] private readonly IResourceCache _resourceCache = default!;
-    [Dependency] private readonly IMapManager _mapManager = default!;
     [Dependency] private readonly IParallelManager _parMan = default!;
     [Dependency] private readonly IRuntimeLog _runtimeLog = default!;
     [Dependency] private readonly IAudioInternal _audio = default!;
-    [Dependency] private readonly MetaDataSystem _metadata = default!;
+    [Dependency] private readonly SharedMapSystem _maps = default!;
     [Dependency] private readonly SharedTransformSystem _xformSys = default!;
     [Dependency] private readonly SharedPhysicsSystem _physics = default!;
 
@@ -49,13 +49,16 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// Per-tick cache of relevant streams.
     /// </summary>
     private readonly List<(EntityUid Entity, AudioComponent Component, TransformComponent Xform)> _streams = new();
-    private EntityUid? _listenerGrid;
     private UpdateAudioJob _updateAudioJob;
 
+    private float _audioFrameTime;
+    private float _audioFrameTimeRemaining;
 
     private EntityQuery<PhysicsComponent> _physicsQuery;
 
     private float _maxRayLength;
+    private float _zOffset;
+    private float _audioEndBuffer;
 
     public override float ZOffset
     {
@@ -79,8 +82,6 @@ public sealed partial class AudioSystem : SharedAudioSystem
         }
     }
 
-    private float _zOffset;
-
     /// <inheritdoc />
     public override void Initialize()
     {
@@ -108,13 +109,31 @@ public sealed partial class AudioSystem : SharedAudioSystem
         SubscribeNetworkEvent<PlayAudioEntityMessage>(OnEntityAudio);
         SubscribeNetworkEvent<PlayAudioPositionalMessage>(OnEntityCoordinates);
 
+        Subs.CVar(CfgManager, CVars.AudioEndBuffer, OnAudioBuffer, true);
         Subs.CVar(CfgManager, CVars.AudioAttenuation, OnAudioAttenuation, true);
         Subs.CVar(CfgManager, CVars.AudioRaycastLength, OnRaycastLengthChanged, true);
+        Subs.CVar(CfgManager, CVars.AudioTickRate, OnAudioTickRate, true);
         InitializeLimit();
     }
 
-    private void OnAudioState(EntityUid uid, AudioComponent component, ref AfterAutoHandleStateEvent args)
+    private void OnAudioBuffer(float value)
     {
+        _audioEndBuffer = value;
+    }
+
+    private void OnAudioTickRate(int obj)
+    {
+        _audioFrameTime = 1f / obj;
+        _audioFrameTimeRemaining = MathF.Min(_audioFrameTimeRemaining, _audioFrameTime);
+    }
+
+    private void OnAudioState(Entity<AudioComponent> entity, ref AfterAutoHandleStateEvent args)
+    {
+        var component = entity.Comp;
+
+        if (component.LifeStage < ComponentLifeStage.Initialized)
+            return;
+
         ApplyAudioParams(component.Params, component);
         component.Source.Global = component.Global;
 
@@ -138,21 +157,29 @@ public sealed partial class AudioSystem : SharedAudioSystem
             case AudioState.Stopped:
                 component.StopPlaying();
                 component.PlaybackPosition = 0f;
-                break;
+                return;
         }
 
         // If playback position changed then update it.
-        if (!string.IsNullOrEmpty(component.FileName))
-        {
-            var position = (float) ((component.PauseTime ?? Timing.CurTime) - component.AudioStart).TotalSeconds;
-            var currentPosition = component.Source.PlaybackPosition;
-            var diff = Math.Abs(position - currentPosition);
+        var position = (float) ((entity.Comp.PauseTime ?? Timing.CurTime) - entity.Comp.AudioStart).TotalSeconds;
+        var currentPosition = entity.Comp.Source.PlaybackPosition;
+        var diff = Math.Abs(position - currentPosition);
 
-            if (diff > 0.1f)
+        // Don't try to set the audio too far ahead.
+        if (!string.IsNullOrEmpty(entity.Comp.FileName))
+        {
+            if (position > GetAudioLengthImpl(entity.Comp.FileName).TotalSeconds - _audioEndBuffer)
             {
-                component.PlaybackPosition = position;
+                entity.Comp.StopPlaying();
+                return;
             }
         }
+
+        // If the difference is minor then we'll just keep playing it.
+        if (diff > 0.1f)
+        {
+            entity.Comp.PlaybackPosition = position;
+        }
     }
 
     /// <summary>
@@ -200,6 +227,10 @@ public sealed partial class AudioSystem : SharedAudioSystem
     private void SetupSource(Entity<AudioComponent> entity, AudioResource audioResource, TimeSpan? length = null)
     {
         var component = entity.Comp;
+        length ??= GetAudioLength(component.FileName);
+
+        // If audio came into range then start playback at the correct position.
+        var offset = ((entity.Comp.PauseTime ?? Timing.CurTime) - component.AudioStart).TotalSeconds;
 
         if (TryAudioLimit(component.FileName))
         {
@@ -216,11 +247,6 @@ public sealed partial class AudioSystem : SharedAudioSystem
             }
         }
 
-        if ((component.Flags & AudioFlags.GridAudio) != 0x0)
-        {
-            _metadata.SetFlag(entity.Owner, MetaDataFlags.Undetachable, true);
-        }
-
         // Need to set all initial data for first frame.
         ApplyAudioParams(component.Params, component);
         component.Source.Global = component.Global;
@@ -228,10 +254,17 @@ public sealed partial class AudioSystem : SharedAudioSystem
         // Don't play until first frame so occlusion etc. are correct.
         component.Gain = 0f;
 
-        length ??= GetAudioLength(component.FileName);
-
-        // If audio came into range then start playback at the correct position.
-        var offset = (Timing.CurTime - component.AudioStart).TotalSeconds % length.Value.TotalSeconds;
+        // If the offset < buffer than just play it from the start.
+        if (offset < AudioDespawnBuffer)
+        {
+            offset = 0;
+        }
+        // Not enough audio to play
+        else if (offset > length.Value.TotalSeconds - _audioEndBuffer)
+        {
+            component.StopPlaying();
+            return;
+        }
 
         if (offset > 0)
         {
@@ -259,6 +292,13 @@ public sealed partial class AudioSystem : SharedAudioSystem
 
     public override void FrameUpdate(float frameTime)
     {
+        _audioFrameTimeRemaining -= frameTime;
+
+        if (_audioFrameTimeRemaining > 0f)
+            return;
+
+        // Clamp to 0 in case we have a really long frame.
+        _audioFrameTimeRemaining = MathF.Max(0f, _audioFrameTime + _audioFrameTimeRemaining);
         var eye = _eyeManager.CurrentEye;
         var localEntity = _playerManager.LocalEntity;
         Vector2 listenerVelocity;
@@ -282,9 +322,6 @@ public sealed partial class AudioSystem : SharedAudioSystem
             _streams.Add((uid, comp, xform));
         }
 
-        _mapManager.TryFindGridAt(ourPos, out var gridUid, out _);
-        _listenerGrid = gridUid == EntityUid.Invalid ? null : gridUid;
-
         try
         {
             _updateAudioJob.OurPosition = ourPos;
@@ -336,52 +373,18 @@ public sealed partial class AudioSystem : SharedAudioSystem
         }
 
         Vector2 worldPos;
-        var gridUid = xform.ParentUid;
+        component.Volume = component.Params.Volume;
 
-        // Handle grid audio differently by using nearest-edge instead of entity centre.
+        // Handle grid audio differently by using grid position.
         if ((component.Flags & AudioFlags.GridAudio) != 0x0)
         {
-            // It's our grid so max volume.
-            if (_listenerGrid == gridUid)
-            {
-                component.Volume = component.Params.Volume;
-                component.Occlusion = 0f;
-                component.Position = listener.Position;
-                return;
-            }
-
-            // TODO: Need a grid-optimised version because this is gonna be expensive.
-            // Just to avoid clipping on and off grid or nearestPoint changing we'll
-            // always set the sound to listener's pos, we'll just manually do gain ourselves.
-            if (_physics.TryGetNearest(gridUid, listener, out _, out var gridDistance))
-            {
-                // Out of range
-                if (gridDistance > component.MaxDistance)
-                {
-                    component.Gain = 0f;
-                    return;
-                }
-
-                var paramsGain = VolumeToGain(component.Params.Volume);
-
-                // Thought I'd never have to manually calculate gain again but this is the least
-                // unpleasant audio I could get at the moment.
-                component.Gain = paramsGain * _audio.GetAttenuationGain(
-                    gridDistance,
-                    component.Params.RolloffFactor,
-                    component.Params.ReferenceDistance,
-                    component.Params.MaxDistance);
-                component.Position = listener.Position;
-                return;
-            }
-
-            // Can't get nearest point so don't play anymore.
-            component.Gain = 0f;
-            return;
+            var parentUid = xform.ParentUid;
+            worldPos = _maps.GetGridPosition(parentUid);
+        }
+        else
+        {
+            worldPos = _xformSys.GetWorldPosition(entity);
         }
-
-        worldPos = _xformSys.GetWorldPosition(entity);
-        component.Volume = component.Params.Volume;
 
         // Max distance check
         var delta = worldPos - listener.Position;
@@ -403,8 +406,15 @@ public sealed partial class AudioSystem : SharedAudioSystem
         }
 
         // Update audio occlusion
-        var occlusion = GetOcclusion(listener, delta, distance, entity);
-        component.Occlusion = occlusion;
+        if ((component.Flags & AudioFlags.NoOcclusion) == AudioFlags.NoOcclusion)
+        {
+            component.Occlusion = 0f;
+        }
+        else
+        {
+            var occlusion = GetOcclusion(listener, delta, distance, entity);
+            component.Occlusion = occlusion;
+        }
 
         // Update audio positions.
         component.Position = worldPos;
@@ -436,6 +446,16 @@ public sealed partial class AudioSystem : SharedAudioSystem
         return occlusion;
     }
 
+    private bool TryGetAudio(ResolvedSoundSpecifier specifier, [NotNullWhen(true)] out AudioResource? audio)
+    {
+        var filename = GetAudioPath(specifier);
+        if (_resourceCache.TryGetResource(new ResPath(filename), out audio))
+            return true;
+
+        Log.Error($"Server tried to play audio file {filename} which does not exist.");
+        return false;
+    }
+
     private bool TryGetAudio(string filename, [NotNullWhen(true)] out AudioResource? audio)
     {
         if (_resourceCache.TryGetResource(new ResPath(filename), out audio))
@@ -454,15 +474,15 @@ public sealed partial class AudioSystem : SharedAudioSystem
         return false;
     }
 
-    public override (EntityUid Entity, AudioComponent Component)? PlayPvs(string? filename, EntityCoordinates coordinates,
+    public override (EntityUid Entity, AudioComponent Component)? PlayPvs(ResolvedSoundSpecifier? specifier, EntityCoordinates coordinates,
         AudioParams? audioParams = null)
     {
-        return PlayStatic(filename, Filter.Local(), coordinates, true, audioParams);
+        return PlayStatic(specifier, Filter.Local(), coordinates, true, audioParams);
     }
 
-    public override (EntityUid Entity, AudioComponent Component)? PlayPvs(string? filename, EntityUid uid, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayPvs(ResolvedSoundSpecifier? specifier, EntityUid uid, AudioParams? audioParams = null)
     {
-        return PlayEntity(filename, Filter.Local(), uid, true, audioParams);
+        return PlayEntity(specifier, Filter.Local(), uid, true, audioParams);
     }
 
     /// <inheritdoc />
@@ -474,6 +494,17 @@ public sealed partial class AudioSystem : SharedAudioSystem
         return null; // uhh Lets hope predicted audio never needs to somehow store the playing audio....
     }
 
+    /// <inheritdoc />
+    public override (EntityUid Entity, AudioComponent Component)? PlayLocal(
+        SoundSpecifier? sound,
+        EntityUid source,
+        EntityUid? soundInitiator,
+        AudioParams? audioParams = null
+    )
+    {
+        return PlayPredicted(sound, source, soundInitiator, audioParams);
+    }
+
     public override (EntityUid Entity, AudioComponent Component)? PlayPredicted(SoundSpecifier? sound, EntityCoordinates coordinates, EntityUid? user, AudioParams? audioParams = null)
     {
         if (Timing.IsFirstTimePredicted && sound != null)
@@ -487,21 +518,21 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// </summary>
     /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
     /// <param name="audioParams"></param>
-    private (EntityUid Entity, AudioComponent Component)? PlayGlobal(string? filename, AudioParams? audioParams = null, bool recordReplay = true)
+    private (EntityUid Entity, AudioComponent Component)? PlayGlobal(ResolvedSoundSpecifier? specifier, AudioParams? audioParams = null, bool recordReplay = true)
     {
-        if (string.IsNullOrEmpty(filename))
+        if (specifier is null)
             return null;
 
         if (recordReplay && _replayRecording.IsRecording)
         {
             _replayRecording.RecordReplayMessage(new PlayAudioGlobalMessage
             {
-                FileName = filename,
+                Specifier = specifier,
                 AudioParams = audioParams ?? AudioParams.Default
             });
         }
 
-        return TryGetAudio(filename, out var audio) ? PlayGlobal(audio, audioParams) : default;
+        return TryGetAudio(specifier, out var audio) ? PlayGlobal(audio, specifier, audioParams) : default;
     }
 
     /// <summary>
@@ -509,12 +540,12 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// </summary>
     /// <param name="stream">The audio stream to play.</param>
     /// <param name="audioParams"></param>
-    public (EntityUid Entity, AudioComponent Component)? PlayGlobal(AudioStream stream, AudioParams? audioParams = null)
+    public (EntityUid Entity, AudioComponent Component)? PlayGlobal(AudioStream stream, ResolvedSoundSpecifier? specifier, AudioParams? audioParams = null)
     {
-        var (entity, component) = CreateAndStartPlayingStream(audioParams, stream);
+        var (entity, component) = CreateAndStartPlayingStream(audioParams, specifier, stream);
         component.Global = true;
         component.Source.Global = true;
-        Dirty(entity, component);
+        DirtyField(entity, component, nameof(AudioComponent.Global));
         return (entity, component);
     }
 
@@ -523,22 +554,22 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// </summary>
     /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
     /// <param name="entity">The entity "emitting" the audio.</param>
-    private (EntityUid Entity, AudioComponent Component)? PlayEntity(string? filename, EntityUid entity, AudioParams? audioParams = null, bool recordReplay = true)
+    private (EntityUid Entity, AudioComponent Component)? PlayEntity(ResolvedSoundSpecifier? specifier, EntityUid entity, AudioParams? audioParams = null, bool recordReplay = true)
     {
-        if (string.IsNullOrEmpty(filename))
+        if (specifier is null)
             return null;
 
         if (recordReplay && _replayRecording.IsRecording)
         {
             _replayRecording.RecordReplayMessage(new PlayAudioEntityMessage
             {
-                FileName = filename,
+                Specifier = specifier,
                 NetEntity = GetNetEntity(entity),
                 AudioParams = audioParams ?? AudioParams.Default
             });
         }
 
-        return TryGetAudio(filename, out var audio) ? PlayEntity(audio, entity, audioParams) : default;
+        return TryGetAudio(specifier, out var audio) ? PlayEntity(audio, entity, specifier, audioParams) : default;
     }
 
     /// <summary>
@@ -547,15 +578,15 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// <param name="stream">The audio stream to play.</param>
     /// <param name="entity">The entity "emitting" the audio.</param>
     /// <param name="audioParams"></param>
-    public (EntityUid Entity, AudioComponent Component)? PlayEntity(AudioStream stream, EntityUid entity, AudioParams? audioParams = null)
+    public (EntityUid Entity, AudioComponent Component)? PlayEntity(AudioStream stream, EntityUid entity, ResolvedSoundSpecifier? specifier, AudioParams? audioParams = null)
     {
         if (TerminatingOrDeleted(entity))
         {
-            Log.Error($"Tried to play coordinates audio on a terminating / deleted entity {ToPrettyString(entity)}");
+            LogAudioPlaybackOnInvalidEntity(specifier, entity);
             return null;
         }
 
-        var playing = CreateAndStartPlayingStream(audioParams, stream);
+        var playing = CreateAndStartPlayingStream(audioParams, specifier, stream);
         _xformSys.SetCoordinates(playing.Entity, new EntityCoordinates(entity, Vector2.Zero));
 
         return playing;
@@ -567,22 +598,22 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// <param name="filename">The resource path to the OGG Vorbis file to play.</param>
     /// <param name="coordinates">The coordinates at which to play the audio.</param>
     /// <param name="audioParams"></param>
-    private (EntityUid Entity, AudioComponent Component)? PlayStatic(string? filename, EntityCoordinates coordinates, AudioParams? audioParams = null, bool recordReplay = true)
+    private (EntityUid Entity, AudioComponent Component)? PlayStatic(ResolvedSoundSpecifier? specifier, EntityCoordinates coordinates, AudioParams? audioParams = null, bool recordReplay = true)
     {
-        if (string.IsNullOrEmpty(filename))
+        if (specifier is null)
             return null;
 
         if (recordReplay && _replayRecording.IsRecording)
         {
             _replayRecording.RecordReplayMessage(new PlayAudioPositionalMessage
             {
-                FileName = filename,
+                Specifier = specifier,
                 Coordinates = GetNetCoordinates(coordinates),
                 AudioParams = audioParams ?? AudioParams.Default
             });
         }
 
-        return TryGetAudio(filename, out var audio) ? PlayStatic(audio, coordinates, audioParams) : default;
+        return TryGetAudio(specifier, out var audio) ? PlayStatic(audio, coordinates, specifier, audioParams) : default;
     }
 
     /// <summary>
@@ -591,41 +622,41 @@ public sealed partial class AudioSystem : SharedAudioSystem
     /// <param name="stream">The audio stream to play.</param>
     /// <param name="coordinates">The coordinates at which to play the audio.</param>
     /// <param name="audioParams"></param>
-    public (EntityUid Entity, AudioComponent Component)? PlayStatic(AudioStream stream, EntityCoordinates coordinates, AudioParams? audioParams = null)
+    public (EntityUid Entity, AudioComponent Component)? PlayStatic(AudioStream stream, EntityCoordinates coordinates, ResolvedSoundSpecifier? specifier, AudioParams? audioParams = null)
     {
         if (TerminatingOrDeleted(coordinates.EntityId))
         {
-            Log.Error($"Tried to play coordinates audio on a terminating / deleted entity {ToPrettyString(coordinates.EntityId)}");
+            LogAudioPlaybackOnInvalidEntity(specifier, coordinates.EntityId);
             return null;
         }
 
-        var playing = CreateAndStartPlayingStream(audioParams, stream);
+        var playing = CreateAndStartPlayingStream(audioParams, specifier, stream);
         _xformSys.SetCoordinates(playing.Entity, coordinates);
         return playing;
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayGlobal(string? filename, Filter playerFilter, bool recordReplay, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayGlobal(ResolvedSoundSpecifier? specifier, Filter playerFilter, bool recordReplay, AudioParams? audioParams = null)
     {
-        return PlayGlobal(filename, audioParams);
+        return PlayGlobal(specifier, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayEntity(string? filename, Filter playerFilter, EntityUid entity, bool recordReplay, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayEntity(ResolvedSoundSpecifier? specifier, Filter playerFilter, EntityUid entity, bool recordReplay, AudioParams? audioParams = null)
     {
-        return PlayEntity(filename, entity, audioParams);
+        return PlayEntity(specifier, entity, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayStatic(string? filename, Filter playerFilter, EntityCoordinates coordinates, bool recordReplay, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayStatic(ResolvedSoundSpecifier? specifier, Filter playerFilter, EntityCoordinates coordinates, bool recordReplay, AudioParams? audioParams = null)
     {
-        return PlayStatic(filename, coordinates, audioParams);
+        return PlayStatic(specifier, coordinates, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayGlobal(string? filename, ICommonSession recipient, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayGlobal(ResolvedSoundSpecifier? specifier, ICommonSession recipient, AudioParams? audioParams = null)
     {
-        return PlayGlobal(filename, audioParams);
+        return PlayGlobal(specifier, audioParams);
     }
 
     public override void LoadStream<T>(Entity<AudioComponent> entity, T stream)
@@ -639,47 +670,48 @@ public sealed partial class AudioSystem : SharedAudioSystem
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayGlobal(string? filename, EntityUid recipient, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayGlobal(ResolvedSoundSpecifier? specifier, EntityUid recipient, AudioParams? audioParams = null)
     {
-        return PlayGlobal(filename, audioParams);
+        return PlayGlobal(specifier, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayEntity(string? filename, ICommonSession recipient, EntityUid uid, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayEntity(ResolvedSoundSpecifier? specifier, ICommonSession recipient, EntityUid uid, AudioParams? audioParams = null)
     {
-        return PlayEntity(filename, uid, audioParams);
+        return PlayEntity(specifier, uid, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayEntity(string? filename, EntityUid recipient, EntityUid uid, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayEntity(ResolvedSoundSpecifier? specifier, EntityUid recipient, EntityUid uid, AudioParams? audioParams = null)
     {
-        return PlayEntity(filename, uid, audioParams);
+        return PlayEntity(specifier, uid, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayStatic(string? filename, ICommonSession recipient, EntityCoordinates coordinates, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayStatic(ResolvedSoundSpecifier? specifier, ICommonSession recipient, EntityCoordinates coordinates, AudioParams? audioParams = null)
     {
-        return PlayStatic(filename, coordinates, audioParams);
+        return PlayStatic(specifier, coordinates, audioParams);
     }
 
     /// <inheritdoc />
-    public override (EntityUid Entity, AudioComponent Component)? PlayStatic(string? filename, EntityUid recipient, EntityCoordinates coordinates, AudioParams? audioParams = null)
+    public override (EntityUid Entity, AudioComponent Component)? PlayStatic(ResolvedSoundSpecifier? specifier, EntityUid recipient, EntityCoordinates coordinates, AudioParams? audioParams = null)
     {
-        return PlayStatic(filename, coordinates, audioParams);
+        return PlayStatic(specifier, coordinates, audioParams);
     }
 
-    private (EntityUid Entity, AudioComponent Component) CreateAndStartPlayingStream(AudioParams? audioParams, AudioStream stream)
+    private (EntityUid Entity, AudioComponent Component) CreateAndStartPlayingStream(AudioParams? audioParams, ResolvedSoundSpecifier? specifier, AudioStream stream)
     {
         var audioP = audioParams ?? AudioParams.Default;
-        var entity = EntityManager.CreateEntityUninitialized("Audio", MapCoordinates.Nullspace);
-        var comp = SetupAudio(entity, null, audioP, stream.Length);
-        LoadStream((entity, comp), stream);
+        var entity = SetupAudio(specifier, audioP, initialize: false, length: stream.Length);
+        LoadStream(entity, stream);
         EntityManager.InitializeAndStartEntity(entity);
+        var comp = entity.Comp;
         var source = comp.Source;
 
         // TODO clamp the offset inside of SetPlaybackPosition() itself.
         var offset = audioP.PlayOffsetSeconds;
-        offset = Math.Clamp(offset, 0f, (float) stream.Length.TotalSeconds - 0.01f);
+        var maxOffset = Math.Max((float) stream.Length.TotalSeconds - 0.01f, 0f);
+        offset = Math.Clamp(offset, 0f, maxOffset);
         source.PlaybackPosition = offset;
 
         // For server we will rely on the adjusted one but locally we will have to adjust it ourselves.
@@ -703,17 +735,17 @@ public sealed partial class AudioSystem : SharedAudioSystem
 
     private void OnEntityCoordinates(PlayAudioPositionalMessage ev)
     {
-        PlayStatic(ev.FileName, GetCoordinates(ev.Coordinates), ev.AudioParams, false);
+        PlayStatic(ev.Specifier, GetCoordinates(ev.Coordinates), ev.AudioParams, false);
     }
 
     private void OnEntityAudio(PlayAudioEntityMessage ev)
     {
-        PlayEntity(ev.FileName, GetEntity(ev.NetEntity), ev.AudioParams, false);
+        PlayEntity(ev.Specifier, GetEntity(ev.NetEntity), ev.AudioParams, false);
     }
 
     private void OnGlobalAudio(PlayAudioGlobalMessage ev)
     {
-        PlayGlobal(ev.FileName, ev.AudioParams, false);
+        PlayGlobal(ev.Specifier, ev.AudioParams, false);
     }
 
     protected override TimeSpan GetAudioLengthImpl(string filename)
@@ -721,6 +753,12 @@ public sealed partial class AudioSystem : SharedAudioSystem
         return _resourceCache.GetResource<AudioResource>(filename).AudioStream.Length;
     }
 
+    private void LogAudioPlaybackOnInvalidEntity(ResolvedSoundSpecifier? specifier, EntityUid entityId)
+    {
+        var soundInfo = specifier?.ToString() ?? "unknown sound";
+        Log.Error($"Tried to play coordinates audio on a terminating / deleted entity {ToPrettyString(entityId)}. Sound: {soundInfo}. Trace: {Environment.StackTrace}");
+    }
+
     #region Jobs
 
     private record struct UpdateAudioJob : IParallelRobustJob

Robust.Client/Audio/HeadlessAudioManager.cs

@@ -13,6 +13,8 @@ namespace Robust.Client.Audio;
 /// </summary>
 internal sealed class HeadlessAudioManager : IAudioInternal
 {
+    private int _audioBuffer;
+
     /// <inheritdoc />
     public void InitializePostWindowing()
     {
@@ -65,6 +67,11 @@ internal sealed class HeadlessAudioManager : IAudioInternal
     {
     }
 
+    /// <inheritdoc />
+    public void Remove(AudioStream stream)
+    {
+    }
+
     /// <inheritdoc />
     public void StopAllAudio()
     {
@@ -101,11 +108,11 @@ internal sealed class HeadlessAudioManager : IAudioInternal
     public AudioStream LoadAudioRaw(ReadOnlySpan<short> samples, int channels, int sampleRate, string? name = null)
     {
         var length = TimeSpan.FromSeconds((double) samples.Length / channels / sampleRate);
-        return new AudioStream(null, length, channels, name);
+        return new AudioStream(this, _audioBuffer++, null, length, channels, name);
     }
 
-    private static AudioStream AudioStreamFromMetadata(AudioMetadata metadata, string? name)
+    private AudioStream AudioStreamFromMetadata(AudioMetadata metadata, string? name)
     {
-        return new AudioStream(null, metadata.Length, metadata.ChannelCount, name, metadata.Title, metadata.Artist);
+        return new AudioStream(this, _audioBuffer++, null, metadata.Length, metadata.ChannelCount, name, metadata.Title, metadata.Artist);
     }
 }

Robust.Client/Audio/IAudioInternal.cs

@@ -44,6 +44,8 @@ internal interface IAudioInternal : IAudioManager
 
     void SetAttenuation(Attenuation attenuation);
 
+    void Remove(AudioStream stream);
+
     /// <summary>
     /// Stops all audio from playing.
     /// </summary>

Robust.Client/Audio/IAudioManager.cs

@@ -1,6 +1,5 @@
 using System;
 using System.IO;
-using Robust.Client.Audio.Sources;
 using Robust.Shared.Audio.Sources;
 
 namespace Robust.Client.Audio;
@@ -11,7 +10,7 @@ namespace Robust.Client.Audio;
 public interface IAudioManager
 {
     IAudioSource? CreateAudioSource(AudioStream stream);
-  
+
     AudioStream LoadAudioOggVorbis(Stream stream, string? name = null);
 
     AudioStream LoadAudioWav(Stream stream, string? name = null);

Robust.Client/Audio/Midi/IMidiRenderer.cs

@@ -6,6 +6,7 @@ using Robust.Shared.Audio.Midi;
 using Robust.Shared.Audio.Sources;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
+using Robust.Shared.Utility;
 
 namespace Robust.Client.Audio.Midi;
 
@@ -33,12 +34,6 @@ public interface IMidiRenderer : IDisposable
     /// </summary>
     bool LoopMidi { get; set; }
 
-    /// <summary>
-    ///     This increases all note on velocities to 127.
-    /// </summary>
-    [Obsolete($"Use {nameof(VelocityOverride)} instead, you can set it to 127 to achieve the same effect.")]
-    bool VolumeBoost { get; set; }
-
     /// <summary>
     ///     The midi program (instrument) the renderer is using.
     /// </summary>
@@ -162,8 +157,13 @@ public interface IMidiRenderer : IDisposable
     /// <summary>
     ///     Loads a new soundfont into the renderer.
     /// </summary>
+    [Obsolete("Use LoadSoundfontResource or LoadSoundfontUser instead")]
     void LoadSoundfont(string filename, bool resetPresets = false);
 
+    void LoadSoundfontResource(ResPath path, bool resetPresets = false);
+
+    void LoadSoundfontUser(ResPath path, bool resetPresets = false);
+
     /// <summary>
     ///     Invoked whenever a new midi event is registered.
     /// </summary>

Robust.Client/Audio/Midi/MidiManager.SoundFontLoad.cs

@@ -0,0 +1,262 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using NFluidsynth;
+using Robust.Shared.ContentPack;
+using Robust.Shared.Utility;
+
+namespace Robust.Client.Audio.Midi;
+
+internal sealed partial class MidiManager
+{
+    // For loading sound fonts, we have to use a callback model where we can only parse a string.
+    // This API, frankly, fucking sucks.
+    //
+    // These prefixes are used to separate the various places a file *can* be loaded from.
+    //
+    // We cannot prevent Fluidsynth from trying to load prefixed paths itself if they are invalid
+    // So if content specifies "/foobar.sf2" to be loaded and it doesn't exist,
+    // Fluidsynth *will* try to fopen("RES:/foobar.sf2"). For this reason I'm putting in some nonsense characters
+    // that will pass through Fluidsynth fine, but make sure the filename is *never* a practically valid OS path.
+    //
+    // NOTE: Raw disk paths *cannot* be prefixed as Fluidsynth needs to load those itself.
+    // Specifically, their .dls loader doesn't respect file callbacks.
+    // If you're curious why this is: it's two-fold:
+    // * The Fluidsynth C code for the .dls loader just doesn't use the file callbacks, period.
+    // * Even if it did, we're not specifying those file callbacks, as they're per loader,
+    //   and we're only adding a *new* sound font loader with file callbacks, not modifying the existing ones.
+    //   The loader for .sfX format and .dls format are different loader objects in Fluidsynth.
+    internal const string PrefixCommon = "!/ -?\x0001";
+    internal const string PrefixLegacy = PrefixCommon + "LEGACY";
+    internal const string PrefixUser = PrefixCommon + "USER";
+    internal const string PrefixResources = PrefixCommon + "RES";
+
+    private void LoadSoundFontSetup(MidiRenderer renderer)
+    {
+        _midiSawmill.Debug($"Loading fallback soundfont {FallbackSoundfont}");
+        // Since the last loaded soundfont takes priority, we load the fallback soundfont before the soundfont.
+        renderer.LoadSoundfontResource(FallbackSoundfont);
+
+        // Load system-specific soundfonts.
+        if (OperatingSystem.IsLinux())
+        {
+            foreach (var filepath in LinuxSoundfonts)
+            {
+                if (!File.Exists(filepath) || !SoundFont.IsSoundFont(filepath))
+                    continue;
+
+                try
+                {
+                    _midiSawmill.Debug($"Loading OS soundfont {filepath}");
+                    renderer.LoadSoundfontDisk(filepath);
+                }
+                catch (Exception)
+                {
+                    continue;
+                }
+
+                break;
+            }
+        }
+        else if (OperatingSystem.IsMacOS())
+        {
+            if (File.Exists(OsxSoundfont) && SoundFont.IsSoundFont(OsxSoundfont))
+            {
+                _midiSawmill.Debug($"Loading OS soundfont {OsxSoundfont}");
+                renderer.LoadSoundfontDisk(OsxSoundfont);
+            }
+        }
+        else if (OperatingSystem.IsWindows())
+        {
+            if (File.Exists(WindowsSoundfont) && SoundFont.IsSoundFont(WindowsSoundfont))
+            {
+                _midiSawmill.Debug($"Loading OS soundfont {WindowsSoundfont}");
+                renderer.LoadSoundfontDisk(WindowsSoundfont);
+            }
+        }
+
+        // Maybe load soundfont specified in environment variable.
+        // Load it here so it can override system soundfonts but not content or user data soundfonts.
+        if (Environment.GetEnvironmentVariable(SoundfontEnvironmentVariable) is { } soundfontOverride)
+        {
+            // Just to avoid funny shit: avoid people smuggling a prefix in here.
+            // I wish I could separate this properly...
+            var (prefix, _) = SplitPrefix(soundfontOverride);
+            if (IsValidPrefix(prefix))
+            {
+                _midiSawmill.Error($"Not respecting {SoundfontEnvironmentVariable} env variable: invalid file path");
+            }
+            else if (File.Exists(soundfontOverride) && SoundFont.IsSoundFont(soundfontOverride))
+            {
+                _midiSawmill.Debug($"Loading environment variable soundfont {soundfontOverride}");
+                renderer.LoadSoundfontDisk(soundfontOverride);
+            }
+        }
+
+        // Load content-specific custom soundfonts, which should override the system/fallback soundfont.
+        _midiSawmill.Debug($"Loading soundfonts from content directory {ContentCustomSoundfontDirectory}");
+        foreach (var file in _resourceManager.ContentFindFiles(ContentCustomSoundfontDirectory))
+        {
+            if (file.Extension != "sf2" && file.Extension != "dls" && file.Extension != "sf3") continue;
+            _midiSawmill.Debug($"Loading content soundfont {file}");
+            renderer.LoadSoundfontResource(file);
+        }
+
+        // Load every soundfont from the user data directory last, since those may override any other soundfont.
+        _midiSawmill.Debug($"Loading soundfonts from user data directory {CustomSoundfontDirectory}");
+        var enumerator = _resourceManager.UserData.Find($"{CustomSoundfontDirectory.ToRelativePath()}*").Item1;
+        foreach (var file in enumerator)
+        {
+            if (file.Extension != "sf2" && file.Extension != "dls" && file.Extension != "sf3") continue;
+            _midiSawmill.Debug($"Loading user soundfont {file}");
+            renderer.LoadSoundfontUser(file);
+        }
+    }
+
+    internal static string PrefixPath(string prefix, string value)
+    {
+        return $"{prefix}:{value}";
+    }
+
+    internal static (string prefix, string? value) SplitPrefix(string filename)
+    {
+        var filenameSplit = filename.Split(':', 2);
+        if (filenameSplit.Length == 1)
+            return (filenameSplit[0], null);
+
+        return (filenameSplit[0], filenameSplit[1]);
+    }
+
+    internal static bool IsValidPrefix(string prefix)
+    {
+        return prefix is PrefixLegacy or PrefixUser or PrefixResources;
+    }
+
+    /// <summary>
+    ///     This class is used to load soundfonts.
+    /// </summary>
+    private sealed class ResourceLoaderCallbacks : SoundFontLoaderCallbacks
+    {
+        private readonly MidiManager _parent;
+        private readonly Dictionary<int, Stream> _openStreams = new();
+        private int _nextStreamId = 1;
+
+        public ResourceLoaderCallbacks(MidiManager parent)
+        {
+            _parent = parent;
+        }
+
+        public override IntPtr Open(string filename)
+        {
+            if (string.IsNullOrEmpty(filename))
+            {
+                return IntPtr.Zero;
+            }
+
+            Stream stream;
+            try
+            {
+                stream = OpenCore(filename);
+            }
+            catch (Exception e)
+            {
+                _parent._midiSawmill.Error($"Error while opening sound font: {e}");
+                return IntPtr.Zero;
+            }
+
+            var id = _nextStreamId++;
+
+            _openStreams.Add(id, stream);
+
+            return (IntPtr) id;
+        }
+
+        private Stream OpenCore(string filename)
+        {
+            var (prefix, value) = SplitPrefix(filename);
+
+            if (!IsValidPrefix(prefix) || value == null)
+                return File.OpenRead(filename);
+
+            var resourceCache = _parent._resourceManager;
+            var resourcePath = new ResPath(value);
+
+            switch (prefix)
+            {
+                case PrefixUser:
+                    return resourceCache.UserData.OpenRead(resourcePath);
+                case PrefixResources:
+                    return resourceCache.ContentFileRead(resourcePath);
+                case PrefixLegacy:
+                    // Try resources first, then try user data.
+                    if (resourceCache.TryContentFileRead(resourcePath, out var stream))
+                        return stream;
+
+                    return resourceCache.UserData.OpenRead(resourcePath);
+                default:
+                    throw new UnreachableException("Invalid prefix specified!");
+            }
+        }
+
+        public override unsafe int Read(IntPtr buf, long count, IntPtr sfHandle)
+        {
+            var length = (int) count;
+            var span = new Span<byte>(buf.ToPointer(), length);
+            var stream = _openStreams[(int) sfHandle];
+
+            // Fluidsynth's docs state that this method should leave the buffer unmodified if it fails. (returns -1)
+            try
+            {
+                // Fluidsynth does a LOT of tiny allocations (frankly, way too much).
+                if (count < 1024)
+                {
+                    // ReSharper disable once SuggestVarOrType_Elsewhere
+                    Span<byte> buffer = stackalloc byte[(int)count];
+
+                    stream.ReadExact(buffer);
+
+                    buffer.CopyTo(span);
+                }
+                else
+                {
+                    var buffer = stream.ReadExact(length);
+
+                    buffer.CopyTo(span);
+                }
+            }
+            catch (EndOfStreamException)
+            {
+                return -1;
+            }
+
+            return 0;
+        }
+
+        public override int Seek(IntPtr sfHandle, long offset, SeekOrigin origin)
+        {
+            var stream = _openStreams[(int) sfHandle];
+
+            stream.Seek(offset, origin);
+
+            return 0;
+        }
+
+        public override long Tell(IntPtr sfHandle)
+        {
+            var stream = _openStreams[(int) sfHandle];
+
+            return (long) stream.Position;
+        }
+
+        public override int Close(IntPtr sfHandle)
+        {
+            if (!_openStreams.Remove((int) sfHandle, out var stream))
+                return -1;
+
+            stream.Dispose();
+            return 0;
+
+        }
+    }
+}

Robust.Client/Audio/Midi/MidiManager.cs

@@ -119,7 +119,7 @@ internal sealed partial class MidiManager : IMidiManager
     private const string OsxSoundfont =
         "/System/Library/Components/CoreAudio.component/Contents/Resources/gs_instruments.dls";
 
-    private const string FallbackSoundfont = "/Midi/fallback.sf2";
+    private static readonly ResPath FallbackSoundfont = new ResPath("/Midi/fallback.sf2");
 
     private const string ContentCustomSoundfontDirectory = "/Audio/MidiCustom/";
 
@@ -265,81 +265,7 @@ internal sealed partial class MidiManager : IMidiManager
 
             var renderer = new MidiRenderer(_settings!, soundfontLoader, mono, this, _audio, _taskManager, _midiSawmill);
 
-            _midiSawmill.Debug($"Loading fallback soundfont {FallbackSoundfont}");
-            // Since the last loaded soundfont takes priority, we load the fallback soundfont before the soundfont.
-            renderer.LoadSoundfont(FallbackSoundfont);
-
-            // Load system-specific soundfonts.
-            if (OperatingSystem.IsLinux())
-            {
-                foreach (var filepath in LinuxSoundfonts)
-                {
-                    if (!File.Exists(filepath) || !SoundFont.IsSoundFont(filepath))
-                        continue;
-
-                    try
-                    {
-                        _midiSawmill.Debug($"Loading OS soundfont {filepath}");
-                        renderer.LoadSoundfont(filepath);
-                    }
-                    catch (Exception)
-                    {
-                        continue;
-                    }
-
-                    break;
-                }
-            }
-            else if (OperatingSystem.IsMacOS())
-            {
-                if (File.Exists(OsxSoundfont) && SoundFont.IsSoundFont(OsxSoundfont))
-                {
-                    _midiSawmill.Debug($"Loading OS soundfont {OsxSoundfont}");
-                    renderer.LoadSoundfont(OsxSoundfont);
-                }
-            }
-            else if (OperatingSystem.IsWindows())
-            {
-                if (File.Exists(WindowsSoundfont) && SoundFont.IsSoundFont(WindowsSoundfont))
-                {
-                    _midiSawmill.Debug($"Loading OS soundfont {WindowsSoundfont}");
-                    renderer.LoadSoundfont(WindowsSoundfont);
-                }
-            }
-
-            // Maybe load soundfont specified in environment variable.
-            // Load it here so it can override system soundfonts but not content or user data soundfonts.
-            if (Environment.GetEnvironmentVariable(SoundfontEnvironmentVariable) is {} soundfontOverride)
-            {
-                if (File.Exists(soundfontOverride) && SoundFont.IsSoundFont(soundfontOverride))
-                {
-                    _midiSawmill.Debug($"Loading environment variable soundfont {soundfontOverride}");
-                    renderer.LoadSoundfont(soundfontOverride);
-                }
-            }
-
-            // Load content-specific custom soundfonts, which should override the system/fallback soundfont.
-            _midiSawmill.Debug($"Loading soundfonts from content directory {ContentCustomSoundfontDirectory}");
-            foreach (var file in _resourceManager.ContentFindFiles(ContentCustomSoundfontDirectory))
-            {
-                if (file.Extension != "sf2" && file.Extension != "dls" && file.Extension != "sf3") continue;
-                _midiSawmill.Debug($"Loading content soundfont {file}");
-                renderer.LoadSoundfont(file.ToString());
-            }
-
-            var userDataPath = _resourceManager.UserData.RootDir == null
-                ? CustomSoundfontDirectory
-                : new ResPath(_resourceManager.UserData.RootDir) / CustomSoundfontDirectory.ToRelativePath();
-
-            // Load every soundfont from the user data directory last, since those may override any other soundfont.
-            _midiSawmill.Debug($"Loading soundfonts from user data directory {userDataPath}");
-            var enumerator = _resourceManager.UserData.Find($"{CustomSoundfontDirectory.ToRelativePath()}*").Item1;
-            foreach (var file in enumerator)
-            {
-                if (file.Extension != "sf2" && file.Extension != "dls" && file.Extension != "sf3") continue;
-                _midiSawmill.Debug($"Loading user soundfont {file}");
-                renderer.LoadSoundfont(file.ToString());
-            }
+            LoadSoundFontSetup(renderer);
 
             renderer.Source.Gain = _gain;
 
@@ -572,130 +498,6 @@ internal sealed partial class MidiManager : IMidiManager
             midiEvent.Velocity);
     }
 
-    /// <summary>
-    ///     This class is used to load soundfonts.
-    /// </summary>
-    private sealed class ResourceLoaderCallbacks : SoundFontLoaderCallbacks
-    {
-        private readonly MidiManager _parent;
-        private readonly Dictionary<int, Stream> _openStreams = new();
-        private int _nextStreamId = 1;
-
-        public ResourceLoaderCallbacks(MidiManager parent)
-        {
-            _parent = parent;
-        }
-
-        public override IntPtr Open(string filename)
-        {
-            if (string.IsNullOrEmpty(filename))
-            {
-                return IntPtr.Zero;
-            }
-
-            Stream? stream;
-            var resourceCache = _parent._resourceManager;
-            var resourcePath = new ResPath(filename);
-
-            if (resourcePath.IsRooted)
-            {
-                // is it in content?
-                if (resourceCache.ContentFileExists(filename))
-                {
-                    if (!resourceCache.TryContentFileRead(filename, out stream))
-                        return IntPtr.Zero;
-                }
-                // is it in userdata?
-                else if (resourceCache.UserData.Exists(resourcePath))
-                {
-                    stream = resourceCache.UserData.OpenRead(resourcePath);
-                }
-                else if (File.Exists(filename))
-                {
-                    stream = File.OpenRead(filename);
-                }
-                else
-                {
-                    return IntPtr.Zero;
-                }
-            }
-            else if (File.Exists(filename))
-            {
-                stream = File.OpenRead(filename);
-            }
-            else
-            {
-                return IntPtr.Zero;
-            }
-
-            var id = _nextStreamId++;
-
-            _openStreams.Add(id, stream);
-
-            return (IntPtr) id;
-        }
-
-        public override unsafe int Read(IntPtr buf, long count, IntPtr sfHandle)
-        {
-            var length = (int) count;
-            var span = new Span<byte>(buf.ToPointer(), length);
-            var stream = _openStreams[(int) sfHandle];
-
-            // Fluidsynth's docs state that this method should leave the buffer unmodified if it fails. (returns -1)
-            try
-            {
-                // Fluidsynth does a LOT of tiny allocations (frankly, way too much).
-                if (count < 1024)
-                {
-                    // ReSharper disable once SuggestVarOrType_Elsewhere
-                    Span<byte> buffer = stackalloc byte[(int)count];
-
-                    stream.ReadExact(buffer);
-
-                    buffer.CopyTo(span);
-                }
-                else
-                {
-                    var buffer = stream.ReadExact(length);
-
-                    buffer.CopyTo(span);
-                }
-            }
-            catch (EndOfStreamException)
-            {
-                return -1;
-            }
-
-            return 0;
-        }
-
-        public override int Seek(IntPtr sfHandle, long offset, SeekOrigin origin)
-        {
-            var stream = _openStreams[(int) sfHandle];
-
-            stream.Seek(offset, origin);
-
-            return 0;
-        }
-
-        public override long Tell(IntPtr sfHandle)
-        {
-            var stream = _openStreams[(int) sfHandle];
-
-            return (long) stream.Position;
-        }
-
-        public override int Close(IntPtr sfHandle)
-        {
-            if (!_openStreams.Remove((int) sfHandle, out var stream))
-                return -1;
-
-            stream.Dispose();
-            return 0;
-
-        }
-    }
-
     #region Jobs
 
     private record struct MidiUpdateJob : IParallelRobustJob

Robust.Client/Audio/Midi/MidiRenderer.SoundFontLoad.cs

@@ -0,0 +1,45 @@
+using System;
+using Robust.Shared.Utility;
+
+namespace Robust.Client.Audio.Midi;
+
+internal sealed partial class MidiRenderer
+{
+    [Obsolete("Use LoadSoundfontResource or LoadSoundfontUser instead")]
+    public void LoadSoundfont(string filename, bool resetPresets = true)
+    {
+        LoadSoundfontCore(
+            MidiManager.PrefixPath(MidiManager.PrefixLegacy, filename),
+            resetPresets);
+    }
+
+    public void LoadSoundfontResource(ResPath path, bool resetPresets = false)
+    {
+        LoadSoundfontCore(
+            MidiManager.PrefixPath(MidiManager.PrefixResources, path.ToString()),
+            resetPresets);
+    }
+
+    public void LoadSoundfontUser(ResPath path, bool resetPresets = false)
+    {
+        LoadSoundfontCore(
+            MidiManager.PrefixPath(MidiManager.PrefixUser, path.ToString()),
+            resetPresets);
+    }
+
+    internal void LoadSoundfontDisk(string path, bool resetPresets = false)
+    {
+        LoadSoundfontCore(
+            path,
+            resetPresets);
+    }
+
+    private void LoadSoundfontCore(string filenameString, bool resetPresets)
+    {
+        lock (_playerStateLock)
+        {
+            _synth.LoadSoundFont(filenameString, resetPresets);
+            MidiSoundfont = 1;
+        }
+    }
+}

Robust.Client/Audio/Midi/MidiRenderer.cs

@@ -16,7 +16,7 @@ using Robust.Shared.ViewVariables;
 
 namespace Robust.Client.Audio.Midi;
 
-internal sealed class MidiRenderer : IMidiRenderer
+internal sealed partial class MidiRenderer : IMidiRenderer
 {
     private readonly IMidiManager _midiManager;
     private readonly ITaskManager _taskManager;
@@ -205,14 +205,6 @@ internal sealed class MidiRenderer : IMidiRenderer
         }
     }
 
-    [ViewVariables(VVAccess.ReadWrite)]
-    [Obsolete($"Use {nameof(VelocityOverride)} instead, you can set it to 127 to achieve the same effect.")]
-    public bool VolumeBoost
-    {
-        get => VelocityOverride == 127;
-        set => VelocityOverride = value ? 127 : null;
-    }
-
     [ViewVariables(VVAccess.ReadWrite)]
     public EntityUid? TrackingEntity { get; set; } = null;
 
@@ -234,6 +226,9 @@ internal sealed class MidiRenderer : IMidiRenderer
             if (value == _master)
                 return;
 
+            if (CheckMasterCycle(value))
+                throw new InvalidOperationException("Tried to set master to a child of this renderer!");
+
             if (_master is { Disposed: false })
             {
                 try
@@ -440,15 +435,6 @@ internal sealed class MidiRenderer : IMidiRenderer
         _sequencer.RemoveEvents(SequencerClientId.Wildcard, SequencerClientId.Wildcard, -1);
     }
 
-    public void LoadSoundfont(string filename, bool resetPresets = true)
-    {
-        lock (_playerStateLock)
-        {
-            _synth.LoadSoundFont(filename, resetPresets);
-            MidiSoundfont = 1;
-        }
-    }
-
     void IMidiRenderer.Render()
     {
         Render();
@@ -737,4 +723,22 @@ internal sealed class MidiRenderer : IMidiRenderer
         _synth?.Dispose();
         _player?.Dispose();
     }
+
+    /// <summary>
+    /// Check that a given renderer is not already a child of this renderer, i.e. it would introduce a cycle if set as master of this renderer.
+    /// </summary>
+    private bool CheckMasterCycle(IMidiRenderer? otherRenderer)
+    {
+        // Doesn't inside drift, cringe.
+
+        while (otherRenderer != null)
+        {
+            if (otherRenderer == this)
+                return true;
+
+            otherRenderer = otherRenderer.Master;
+        }
+
+        return false;
+    }
 }

Robust.Client/Audio/Sources/AudioSource.cs

@@ -13,7 +13,7 @@ internal sealed class AudioSource : BaseAudioSource
     /// <summary>
     /// Underlying stream to the audio.
     /// </summary>
-    private readonly AudioStream _sourceStream;
+    internal readonly AudioStream SourceStream;
 
 #if DEBUG
     private bool _didPositionWarning;
@@ -21,7 +21,7 @@ internal sealed class AudioSource : BaseAudioSource
 
     public AudioSource(AudioManager master, int sourceHandle, AudioStream sourceStream) : base(master, sourceHandle)
     {
-        _sourceStream = sourceStream;
+        SourceStream = sourceStream;
     }
 
     /// <inheritdoc />
@@ -47,13 +47,13 @@ internal sealed class AudioSource : BaseAudioSource
 #if DEBUG
             // OpenAL doesn't seem to want to play stereo positionally.
             // Log a warning if people try to.
-            if (_sourceStream.ChannelCount > 1 && !_didPositionWarning)
+            if (SourceStream.ChannelCount > 1 && !_didPositionWarning)
             {
                 _didPositionWarning = true;
                 Master.OpenALSawmill.Warning("Attempting to set position on audio source with multiple audio channels! Stream: '{0}'.  Make sure the audio is MONO, not stereo.",
-                    _sourceStream.Name);
+                    SourceStream.Name);
                 // warning isn't enough, people just ignore it :(
-                DebugTools.Assert(false, $"Attempting to set position on audio source with multiple audio channels! Stream: '{_sourceStream.Name}'. Make sure the audio is MONO, not stereo.");
+                DebugTools.Assert(false, $"Attempting to set position on audio source with multiple audio channels! Stream: '{SourceStream.Name}'. Make sure the audio is MONO, not stereo.");
             }
 #endif
 

Robust.Client/Audio/Sources/BaseAudioSource.cs

@@ -208,6 +208,12 @@ public abstract class BaseAudioSource : IAudioSource
         }
         set
         {
+            if (float.IsNaN(value))
+            {
+                Master.LogError($"Tried to set NaN gain, setting audio source to 0f: {Environment.StackTrace}");
+                value = 0f;
+            }
+
             _checkDisposed();
             var priorOcclusion = 1f;
             if (!IsEfxSupported)