Implement MSML_ExtendBaseTestClass (Test classes should be derived from BaseTestClass) #4746
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…om BaseTestClass)
| context.RegisterCompilationStartAction(AnalyzeCompilation); | ||
| } | ||
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| private void AnalyzeCompilation(CompilationStartAnalysisContext context) |
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This method sets up the analysis for a compilation, which is the compilation of one assembly (normally one project, but can occur more than once for a project if you multi-target).
| if (!(context.Compilation.GetTypeByMetadataName("Xunit.FactAttribute") is { } factAttribute)) | ||
| { | ||
| return; | ||
| } |
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If the project doesn't reference Xunit.FactAttribute, then return early because there are no test classes of interest.
| var analyzerImpl = new AnalyzerImpl(context.Compilation, factAttribute); | ||
| context.RegisterSymbolAction(analyzerImpl.AnalyzeNamedType, SymbolKind.NamedType); |
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analyzerImpl is a state object in the context of one Compilation. Analyzers which require state (in this case to cache the symbol lookups of FactAttribute and BaseTestClass) can do so in one of the *StartAnalysisContext callbacks.
| var namedType = (INamedTypeSymbol)context.Symbol; | ||
| if (namedType.TypeKind != TypeKind.Class) | ||
| return; |
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This method is called for all named types. We know the symbol is a INamedTypeSymbol, but we don't know what kind of named type it is. Since we only want to analyze classes, we check that and return immediately for any other type kind.
| if (ExtendsBaseTestClass(namedType)) | ||
| return; |
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Avoid looking at all the members if the class already extends BaseTestClass.
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| for (var current = namedType; current is object; current = current.BaseType) | ||
| { | ||
| if (Equals(current, _baseTestClass)) |
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Symbols need to be compared with Equals (as opposed to ==). We have an analyzer for this to help developers avoid mistakes.
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| public override void Initialize(AnalysisContext context) | ||
| { | ||
| context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None); |
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None is the normal behavior for analyzers, but it is not the default behavior. It is a combination of two things:
- This analyzer does not need to analyze generated code (i.e. it will not receive Named Type symbol callbacks for types defined in generated code files, such as *.Designer.cs files). Some analyzers (e.g. analysis of unused code) will not be accurate if generated code is skipped, but this analyzer is not impacted.
- This analyzer does not report diagnostics in generated code.
| public override void Initialize(AnalysisContext context) | ||
| { | ||
| context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.None); | ||
| context.EnableConcurrentExecution(); |
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This analyzer is safe for concurrent execution. In particular, AnalyzerImpl.AnalyzeNamedType can be called concurrently for different types.
| [test/Microsoft.Extensions.ML.Tests/**.cs] | ||
| # MSML_ExtendBaseTestClass: Test classes should be derived from BaseTestClass | ||
| dotnet_diagnostic.MSML_ExtendBaseTestClass.severity = none |
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This block disables the MSML_ExtendBaseTestClass rule for source files under test/Microsoft.Extensions.ML.Tests. This is required because one or more classes in this folder is considered a test class by this analyzer but does not extend BaseTestClass. However, this pull request only implements the analyzer; a future pull request will remove these lines from the configuration file and update the test classes to correct the violations.
| [test/Microsoft.ML.CodeAnalyzer.Tests/**.cs] | ||
| # BaseTestClass does not apply for analyzer testing. | ||
| # MSML_ExtendBaseTestClass: Test classes should be derived from BaseTestClass | ||
| dotnet_diagnostic.MSML_ExtendBaseTestClass.severity = none |
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We never want to report BaseTestClass violations in the code analyzer tests. These are "meta" tests for the analyzer itself, and thus follows the patterns for analyzer testing instead of the patterns for ML.NET testing.
All current violations are excluded from analysis via .editorconfig. After this is merged, someone can enable the diagnostic in one project at a time and ensure there are no violations.