Release of new minor version v2.10

.config/dotnet-tools.json

@@ -17,7 +17,7 @@
       "rollForward": false
     },
     "dotnet-dump": {
-      "version": "9.0.661903",
+      "version": "10.0.731102",
       "commands": [
         "dotnet-dump"
       ],

.github/workflows/ci.yml

@@ -182,32 +182,36 @@ jobs:
           dotnet new bunit --no-restore -o ${{ github.workspace }}/TemplateTestXunit
           echo '<?xml version="1.0" encoding="utf-8"?><Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003"></Project>' >> ${{ github.workspace }}/TemplateTestXunit/Directory.Build.props
           echo '<Project><PropertyGroup><ManagePackageVersionsCentrally>false</ManagePackageVersionsCentrally></PropertyGroup></Project>' >> ${{ github.workspace }}/TemplateTestXunit/Directory.Packages.props
+          echo '{"sdk":{"rollForward":"latestMajor","allowPrerelease":true}}' >> ${{ github.workspace }}/TemplateTestXunit/global.json
           dotnet restore ${{ github.workspace }}/TemplateTestXunit --source https://api.nuget.org/v3/index.json --source ${{ env.NUGET_DIRECTORY }}
-          dotnet test ${{ github.workspace }}/TemplateTestXunit
+          cd ${{ github.workspace }}/TemplateTestXunit && dotnet test
 
       - name: ✔ Verify xUnit.v3 template
         run: |
             dotnet new bunit --framework xunitv3 --no-restore -o ${{ github.workspace }}/TemplateTestXunitv3
             echo '<?xml version="1.0" encoding="utf-8"?><Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003"></Project>' >> ${{ github.workspace }}/TemplateTestXunitv3/Directory.Build.props
             echo '<Project><PropertyGroup><ManagePackageVersionsCentrally>false</ManagePackageVersionsCentrally></PropertyGroup></Project>' >> ${{ github.workspace }}/TemplateTestXunitv3/Directory.Packages.props
+            echo '{"sdk":{"rollForward":"latestMajor","allowPrerelease":true}}' >> ${{ github.workspace }}/TemplateTestXunitv3/global.json
             dotnet restore ${{ github.workspace }}/TemplateTestXunitv3 --source https://api.nuget.org/v3/index.json --source ${{ env.NUGET_DIRECTORY }}
-            dotnet test ${{ github.workspace }}/TemplateTestXunitv3
+            cd ${{ github.workspace }}/TemplateTestXunitv3 && dotnet test
 
       - name: ✔ Verify NUnit template
         run: |
           dotnet new bunit --framework nunit --no-restore -o ${{ github.workspace }}/TemplateTestNunit
           echo '<?xml version="1.0" encoding="utf-8"?><Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003"></Project>' >> ${{ github.workspace }}/TemplateTestNunit/Directory.Build.props
           echo '<Project><PropertyGroup><ManagePackageVersionsCentrally>false</ManagePackageVersionsCentrally></PropertyGroup></Project>' >> ${{ github.workspace }}/TemplateTestNunit/Directory.Packages.props
+          echo '{"sdk":{"rollForward":"latestMajor","allowPrerelease":true}}' >> ${{ github.workspace }}/TemplateTestNunit/global.json
           dotnet restore ${{ github.workspace }}/TemplateTestNunit --source https://api.nuget.org/v3/index.json --source ${{ env.NUGET_DIRECTORY }}
-          dotnet test ${{ github.workspace }}/TemplateTestNunit
+          cd ${{ github.workspace }}/TemplateTestNunit && dotnet test
 
       - name: ✔ Verify MSTest template
         run: |
           dotnet new bunit --framework mstest --no-restore -o ${{ github.workspace }}/TemplateTestMstest
           echo '<?xml version="1.0" encoding="utf-8"?><Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003"></Project>' >> ${{ github.workspace }}/TemplateTestMstest/Directory.Build.props
           echo '<Project><PropertyGroup><ManagePackageVersionsCentrally>false</ManagePackageVersionsCentrally></PropertyGroup></Project>' >> ${{ github.workspace }}/TemplateTestMstest/Directory.Packages.props
+          echo '{"sdk":{"rollForward":"latestMajor","allowPrerelease":true}}' >> ${{ github.workspace }}/TemplateTestMstest/global.json
           dotnet restore ${{ github.workspace }}/TemplateTestMstest --source https://api.nuget.org/v3/index.json --source ${{ env.NUGET_DIRECTORY }}
-          dotnet test ${{ github.workspace }}/TemplateTestMstest
+          cd ${{ github.workspace }}/TemplateTestMstest && dotnet test
 
   validate-docs:
     runs-on: ubuntu-latest
@@ -251,7 +255,8 @@ jobs:
         run: dotnet build -c release
 
       - name: 🧪 Run sample unit tests
-        run: dotnet test docs/samples/samples.sln -p:VSTestUseMSBuildOutput=false -f net8.0
+        working-directory: docs/samples
+        run: dotnet test samples.sln -p:VSTestUseMSBuildOutput=false -f net8.0
 
       - name: 📄 Build docs
         working-directory: ./docs/site

.github/workflows/docs-deploy.yml

@@ -87,7 +87,8 @@ jobs:
         run: dotnet build /p:PublicRelease=true -c release
 
       - name: 🛠️ Verify docs samples
-        run: dotnet test docs/samples/samples.sln
+        working-directory: docs/samples
+        run: dotnet test samples.sln
 
       - name: 📄 Building docs
         working-directory: ./docs/site

CHANGELOG.md

@@ -6,6 +6,10 @@ All notable changes to **bUnit** will be documented in this file. The project ad
 
 ## [Unreleased]
 
+### Fixed
+
+- `BunitHtmlParser.Dispose()` no longer throws `InvalidOperationException: Collection was modified` when a parse is in flight on another thread during test teardown. Reported by [@thimobuchheister](https://github.com/thimobuchheister) in #1892. Fixed by [@linkdotnet](https://github.com/linkdotnet).
+
 ## [2.9.0] - 2026-08-03
 
 ### Changed

Directory.Packages.props

@@ -8,7 +8,7 @@
 		<GlobalPackageReference Include="AsyncFixer" Version="2.1.0" PrivateAssets="All" IncludeAssets="Runtime;Build;Native;contentFiles;Analyzers"/>
 		<GlobalPackageReference Include="SonarAnalyzer.CSharp" Version="10.29.0.143774" PrivateAssets="All" IncludeAssets="Runtime;Build;Native;contentFiles;Analyzers"/>
 		<PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0" />
-		<PackageVersion Include="Meziantou.Polyfill" Version="1.0.158" />
+		<PackageVersion Include="Meziantou.Polyfill" Version="1.0.164" />
 	</ItemGroup>
 
 	<ItemGroup Label="Shared">
@@ -18,12 +18,12 @@
 		<PackageVersion Include="Serilog" Version="4.4.0"/>
 		<PackageVersion Include="Serilog.Expressions" Version="5.0.0"/>
 		<PackageVersion Include="AngleSharp.Diffing" Version="1.1.1"/>
-		<PackageVersion Include="AngleSharp" Version="1.7.0"/>
-		<PackageVersion Include="AngleSharp.Css" Version="1.0.1"/>
+		<PackageVersion Include="AngleSharp" Version="1.8.0"/>
+		<PackageVersion Include="AngleSharp.Css" Version="1.1.0"/>
 	</ItemGroup>
 
 	<ItemGroup Label="Package Versioning">
-		<PackageVersion Include="Nerdbank.GitVersioning" Version="3.10.91" />
+		<PackageVersion Include="Nerdbank.GitVersioning" Version="3.10.94" />
 	</ItemGroup>
 
 	<ItemGroup Condition="'$(TargetFramework)' == 'net8.0'">
@@ -91,24 +91,24 @@
 		<PackageVersion Include="AutoFixture.Xunit3" Version="4.19.0"/>
 		<PackageVersion Include="MSTest.TestAdapter" Version="3.6.0" />
 		<PackageVersion Include="MSTest.TestFramework" Version="3.6.0" />
-		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.8.1"/>
+		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.9.0"/>
 		<PackageVersion Include="Moq" Version="4.20.72" />
-		<PackageVersion Include="NSubstitute" Version="6.0.0" />
+		<PackageVersion Include="NSubstitute" Version="6.2.0" />
 		<PackageVersion Include="NUnit3TestAdapter" Version="5.0.0" />
 		<PackageVersion Include="RichardSzalay.MockHttp" Version="7.0.0" />
 		<PackageVersion Include="Serilog.Extensions.Logging" Version="10.0.0" />
 		<PackageVersion Include="Shouldly" Version="4.3.0"/>
 		<PackageVersion Include="Verify.SourceGenerators" Version="2.5.0"/>
-		<PackageVersion Include="Verify.XunitV3" Version="31.28.0"/>
+		<PackageVersion Include="Verify.XunitV3" Version="32.0.0"/>
 		<PackageVersion Include="Xunit.Combinatorial" Version="2.0.24"/>
 		<PackageVersion Include="coverlet.collector" Version="10.0.1" />
 		<PackageVersion Include="coverlet.msbuild" Version="10.0.1" />
 		<PackageVersion Include="nunit" Version="4.4.0" />
 		<PackageVersion Include="xunit" Version="2.9.3"/>
-		<PackageVersion Include="xunit.v3" Version="3.2.2"/>
-		<PackageVersion Include="xunit.v3.extensibility.core" Version="3.2.2" />
-		<PackageVersion Include="xunit.v3.assert" Version="3.2.2"/>
-		<PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5"/>
+		<PackageVersion Include="xunit.v3" Version="4.0.0"/>
+		<PackageVersion Include="xunit.v3.extensibility.core" Version="4.0.0" />
+		<PackageVersion Include="xunit.v3.assert" Version="4.0.0"/>
+		<PackageVersion Include="xunit.runner.visualstudio" Version="4.0.0"/>
 	</ItemGroup>
 
 	<ItemGroup Label="Source Code Generators">

docs/samples/global.json

@@ -0,0 +1,6 @@
+{
+	"sdk": {
+		"rollForward": "latestMajor",
+		"allowPrerelease": true
+	}
+}

global.json

@@ -2,5 +2,8 @@
 	"sdk": {
 		"rollForward": "latestMajor",
 		"allowPrerelease": true
+	},
+	"test": {
+		"runner": "Microsoft.Testing.Platform"
 	}
 }

src/bunit.generators.internal/bunit.generators.internal.csproj

@@ -2,7 +2,7 @@
 
 	<PropertyGroup>
 		<TargetFramework>netstandard2.0</TargetFramework>
-		<LangVersion>12.0</LangVersion>
+		<LangVersion>14.0</LangVersion>
 		<EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
 		<RootNamespace>Bunit</RootNamespace>
 		<IsPackable>false</IsPackable>

src/bunit.generators/bunit.generators.csproj

@@ -2,7 +2,7 @@
 
 	<PropertyGroup>
 		<TargetFramework>netstandard2.0</TargetFramework>
-		<LangVersion>12.0</LangVersion>
+		<LangVersion>14.0</LangVersion>
 		<EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
 		<RootNamespace>Bunit</RootNamespace>
 	</PropertyGroup>

src/bunit/JSInterop/JSRuntimeInvocationNotSetException.cs

@@ -64,7 +64,7 @@ private static string CreateErrorMessage(JSRuntimeInvocation invocation)
 
 	private static string GetArguments(JSRuntimeInvocation invocation)
 	{
-		if (!invocation.Arguments.Any())
+		if (invocation.Arguments.Count == 0)
 			return $"\"{invocation.Identifier}\"";
 
 		var argStrings = invocation.Arguments.Select(FormatArgument).Prepend($"\"{invocation.Identifier}\"");

src/bunit/JSInterop/JSRuntimeUnhandledInvocationException.cs

@@ -60,7 +60,7 @@ private static string CreateErrorMessage(JSRuntimeInvocation invocation)
 				sb.AppendLine(FormattableString.Invariant($"    Setup<{GetReturnTypeName(invocation.ResultType)}>({GetArguments(invocation)})"));
 			}
 
-			if (invocation.Arguments.Any())
+			if (invocation.Arguments.Count > 0)
 			{
 				sb.AppendLine("or the following, to match any arguments:");
 				if (invocation.IsVoidResultInvocation)

src/bunit/Rendering/BunitHtmlParser.cs

@@ -23,6 +23,8 @@ internal sealed class BunitHtmlParser : IDisposable
 	private readonly IBrowsingContext context;
 	private readonly HtmlParser htmlParser;
 	private readonly List<IDocument> documents = new();
+	private readonly object parserLock = new();
+	private bool disposed;
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref="BunitHtmlParser"/> class
@@ -69,13 +71,16 @@ public INodeList Parse([StringSyntax("Html")] string markup)
 	{
 		ArgumentNullException.ThrowIfNull(markup);
 
-		var document = GetNewDocumentAsync().GetAwaiter().GetResult();
+		lock (parserLock)
+		{
+			var document = GetNewDocumentAsync().GetAwaiter().GetResult();
 
-		var (ctx, matchedElement) = GetParseContext(markup, document);
+			var (ctx, matchedElement) = GetParseContext(markup, document);
 
-		return ctx is null && matchedElement is not null
-			? ParseSpecial(markup, matchedElement)
-			: htmlParser.ParseFragment(markup, ctx!);
+			return ctx is null && matchedElement is not null
+				? ParseSpecial(markup, matchedElement)
+				: htmlParser.ParseFragment(markup, ctx!);
+		}
 	}
 
 	private INodeList ParseSpecial(string markup, string matchedElement)
@@ -158,10 +163,18 @@ private async Task<IDocument> GetNewDocumentAsync()
 	/// <inheritdoc/>
 	public void Dispose()
 	{
-		context.Dispose();
-		foreach (var doc in documents)
+		lock (parserLock)
 		{
-			doc.Dispose();
+			if (disposed)
+				return;
+
+			disposed = true;
+
+			context.Dispose();
+			foreach (var doc in documents)
+			{
+				doc.Dispose();
+			}
 		}
 	}
 

tests/bunit.tests/BlazorE2E/ComponentRenderingTest.cs

@@ -669,7 +669,7 @@ public async Task CanHandleRemovedParentObjects()
 
 		cut.Find("button").Click();
 
-		await cut.WaitForStateAsync(() => !cut.FindAll("div").Any());
+		await cut.WaitForStateAsync(() => cut.FindAll("div").Count == 0);
 		cut.FindAll("div").Count.ShouldBe(0);
 	}
 
@@ -681,7 +681,7 @@ public void CanHandleRemovedParentObjects_Sync()
 
 		cut.Find("button").Click();
 
-		cut.WaitForState(() => !cut.FindAll("div").Any());
+		cut.WaitForState(() => cut.FindAll("div").Count == 0);
 		cut.FindAll("div").Count.ShouldBe(0);
 	}
 
@@ -693,7 +693,7 @@ public async Task CanHandleRemovedParentObjectsAsync()
 
 		await cut.Find("button").ClickAsync(new MouseEventArgs());
 
-		await cut.WaitForStateAsync(() => !cut.FindAll("div").Any());
+		await cut.WaitForStateAsync(() => cut.FindAll("div").Count == 0);
 		cut.FindAll("div").Count.ShouldBe(0);
 	}
 
@@ -717,7 +717,7 @@ public async Task CanHandleRemovedParentObjectsAsync_Sync()
 
 		await cut.Find("button").ClickAsync(new MouseEventArgs());
 
-		cut.WaitForState(() => !cut.FindAll("div").Any());
+		cut.WaitForState(() => cut.FindAll("div").Count == 0);
 		cut.FindAll("div").Count.ShouldBe(0);
 	}
 

tests/bunit.tests/Rendering/BunitHtmlParserTest.cs

@@ -170,6 +170,63 @@ public void Test021()
 		actual[1].ShouldBeAssignableTo<IHtmlHtmlElement>();
 	}
 
+	[Fact(DisplayName = "Dispose() does not throw while another thread is parsing")]
+	public async Task DisposeDoesNotThrowWhileAnotherThreadIsParsing()
+	{
+		using var cts = new CancellationTokenSource();
+		using var parser = new BunitHtmlParser();
+		var parseCount = 0;
+		Exception? parseException = null;
+
+		var parsing = Task.Run(
+			() =>
+			{
+				while (!cts.IsCancellationRequested)
+				{
+					try
+					{
+						parser.Parse("<p>Hello world</p>");
+						Interlocked.Increment(ref parseCount);
+					}
+					catch (InvalidOperationException ex)
+					{
+						// "Collection was modified" - the race this test guards against.
+						parseException = ex;
+						return;
+					}
+					catch (Exception)
+					{
+						// Expected once Dispose() has completed: parsing against a
+						// disposed AngleSharp browsing context.
+					}
+				}
+			},
+			CancellationToken.None);
+
+		// Let the parser build up a sizeable document list, so the enumeration in
+		// Dispose() is long enough to overlap with a concurrent call to Parse().
+		while (Volatile.Read(ref parseCount) < 100)
+		{
+			await Task.Yield();
+		}
+
+		Should.NotThrow(parser.Dispose);
+
+		await cts.CancelAsync();
+		await parsing;
+
+		parseException.ShouldBeNull();
+	}
+
+	[Fact(DisplayName = "Dispose() is idempotent")]
+	public void DisposeIsIdempotent()
+	{
+		using var parser = new BunitHtmlParser();
+		parser.Dispose();
+
+		Should.NotThrow(parser.Dispose);
+	}
+
 	private static void VerifyElementParsedWithId(string expectedElementName, List<INode> actual)
 	{
 		var elm = actual.OfType<IElement>()

version.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/main/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "2.9",
+  "version": "2.10",
   "assemblyVersion": {
     "precision": "revision"
   },