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Merged
jjonescz merged 3 commits into from
Feb 25, 2026
+60 −8
Merged

Validate generator diagnostics after incremental updates #82113

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25cfa1e
Validate generator diagnostics after incremental updates
jjonescz Jan 22, 2026
b293df3
Improve formatting
jjonescz Jan 22, 2026
f09e19f
Simplify expected exception message computation
jjonescz Jan 23, 2026
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59 changes: 51 additions & 8 deletions src/Compilers/CSharp/Test/Semantic/SourceGeneration/GeneratorDriverTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -20,11 +20,15 @@
using Roslyn.Test.Utilities.TestGenerators;
using Roslyn.Utilities;
using Xunit;
using Xunit.Abstractions;
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namespace Microsoft.CodeAnalysis.CSharp.Semantic.UnitTests.SourceGeneration
{
public class GeneratorDriverTests
public class GeneratorDriverTests(ITestOutputHelper output)
: CSharpTestBase
{
private readonly ITestOutputHelper _output = output;

[Fact]
public void Running_With_No_Changes_Is_NoOp()
{
Expand Down Expand Up @@ -3891,6 +3895,48 @@ public void Diagnostic_SpanOutsideRange_Incremental()
compilation.VerifyDiagnostics();
}

[Fact]
[WorkItem("https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1805836")]
[WorkItem("https://github.com/dotnet/roslyn/issues/82032")]
public void Diagnostic_SpanOutsideRange_Incremental_Update()
{
var source = "class SomewhatLongClassName {}";
var parseOptions = TestOptions.RegularPreview;
Compilation compilation = CreateCompilation(source, options: TestOptions.DebugDll, parseOptions: parseOptions, sourceFileName: "/original");
compilation.VerifyDiagnostics();

var generator = new PipelineCallbackGenerator(ctx =>
{
var inputs = ctx.SyntaxProvider.CreateSyntaxProvider(
static (node, ct) => node.IsKind(SyntaxKind.ClassDeclaration),
static (ctx, ct) => 0);
ctx.RegisterSourceOutput(inputs, (ctx, input) =>
{
var tree = compilation.SyntaxTrees.Single();
ctx.ReportDiagnostic(CodeAnalysis.Diagnostic.Create(
"TEST0001",
"Test",
"Test diagnostic",
DiagnosticSeverity.Warning,
DiagnosticSeverity.Warning,
isEnabledByDefault: true,
warningLevel: 1,
location: Location.Create(tree, TextSpan.FromBounds(20, 21))));
});
}).AsSourceGenerator();

GeneratorDriver driver = CSharpGeneratorDriver.Create(new[] { generator }, parseOptions: parseOptions);
driver = driver.RunGeneratorsAndUpdateCompilation(compilation, out compilation, out var diagnostics);
diagnostics.Verify(Diagnostic("TEST0001", "a").WithLocation(1, 21));

source = "class C {}";
compilation = compilation.ReplaceSyntaxTree(compilation.SyntaxTrees.Single(), CSharpSyntaxTree.ParseText(source, parseOptions, path: "/original"));
driver = driver.RunGeneratorsAndUpdateCompilation(compilation, out compilation, out diagnostics);

VerifyArgumentExceptionDiagnostic(diagnostics.Single(), nameof(PipelineCallbackGenerator), string.Format(CodeAnalysisResources.InvalidDiagnosticLocationReported, "TEST0001", "/original"), "diagnostic");
compilation.VerifyDiagnostics();
}

[ConditionalFact(typeof(IsEnglishLocal))]
[WorkItem("https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1805836")]
public void Diagnostic_SpanOutsideRange_Incremental_AdditionalLocations()
Expand Down Expand Up @@ -4237,19 +4283,16 @@ static void replace(ref Compilation compilation, CSharpParseOptions parseOptions
}
}

private static void VerifyArgumentExceptionDiagnostic(
private void VerifyArgumentExceptionDiagnostic(
Diagnostic diagnostic,
string generatorName,
string message,
string parameterName,
bool initialization = false)
{
var expectedMessage =
#if NET
$"{message} (Parameter '{parameterName}')";
#else
$"{message}{Environment.NewLine}Parameter name: {parameterName}";
#endif
_output.WriteLine(diagnostic.ToString());

@CyrusNajmabadi CyrusNajmabadi Jan 22, 2026

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needed?

@jjonescz jjonescz Jan 22, 2026

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It was useful to see the stacktrace that customers will see even though we don't validate it in the test obviously


var expectedMessage = new ArgumentException(message: message, paramName: parameterName).Message;

@chsienki chsienki Jan 24, 2026

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Neat :)

VerifyGeneratorExceptionDiagnostic<ArgumentException>(diagnostic, generatorName, expectedMessage, initialization);
}

Expand Down
9 changes: 9 additions & 0 deletions src/Compilers/Core/Portable/SourceGeneration/GeneratorDriver.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -427,6 +427,15 @@ private static ImmutableArray<Diagnostic> FilterDiagnostics(Compilation compilat
ArrayBuilder<Diagnostic> filteredDiagnostics = ArrayBuilder<Diagnostic>.GetInstance();
foreach (var diag in generatorDiagnostics)
{
try
{
DiagnosticAnalysisContextHelpers.VerifyArguments(diag, compilation, isSupportedDiagnostic: static (_, _) => true, cancellationToken);
}
catch (ArgumentException ex)
{
throw new UserFunctionException(ex);
}

if (compilation.Options.FilterDiagnostic(diag, cancellationToken) is { } filtered &&
suppressMessageState.ApplySourceSuppressions(filtered) is { } effective)
{
Expand Down
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