Enable trim/AOT analyzers on System.Text.Json source generator tests

[eiriktsarpalis]

Enables the trim/AOT analyzers on the System.Text.Json source generator test projects so that AOT/trim regressions are caught at PR build time, instead of only surfacing in the Native AOT outerloop runs that don't execute on regular PRs.

This is a follow up to #129965.

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[Copilot]

Pull request overview

This PR re-enables trim/AOT analyzers for the System.Text.Json source generator test projects and updates shared test code to be analyzer-clean (primarily by avoiding reflection-based serialization paths and annotating reflection usage explicitly).

Changes:

• Re-enable trim/AOT analyzers for the source-generator Roslyn test projects (remove per-project opt-outs).
• Update tests to prefer JsonTypeInfo-based APIs (e.g., options.GetTypeInfo<T>(), GetTypeInfo<T>()) and add Requires* / DynamicallyAccessedMembers annotations where reflection remains intentional.
• Add missing attribute sources for non-NetCoreAppCurrent / .NET Framework builds so new annotations compile.

Reviewed changes

Copilot reviewed 42 out of 42 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/libraries/System.Text.Json/tests/System.Text.Json.Tests/System.Text.Json.Tests.csproj	Add missing CodeAnalysis / CompilerServices attribute source files for .NET Framework build of the test project.
src/libraries/System.Text.Json/tests/System.Text.Json.Tests/Serialization/DomTests.cs	Use generic GetTypeInfo<T>() to avoid reflection-based GetTypeInfo(Type) + cast patterns.
src/libraries/System.Text.Json/tests/System.Text.Json.Tests/JsonNode/JsonValueTests.cs	Switch to generic GetTypeInfo<T>() usage for analyzer-friendliness.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/TestClasses.CustomConverters.cs	Route converter serialization through options.GetTypeInfo<T>() APIs instead of reflection-based overloads.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/System.Text.Json.SourceGeneration.Tests.targets	Add missing attribute source files for non-current TFMs and configure source-gen test compilation.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/System.Text.Json.SourceGeneration.Roslyn4.4.Tests.csproj	Remove EnableTrimAnalyzer/EnableAotAnalyzer=false opt-out to re-enable analyzers.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/System.Text.Json.SourceGeneration.Roslyn3.11.Tests.csproj	Remove EnableTrimAnalyzer/EnableAotAnalyzer=false opt-out to re-enable analyzers.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/SerializationLogicTests.cs	Adjust enum-converter usage to be compatible with analyzer expectations in source-gen contexts.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/Serialization/PropertyVisibilityTests.cs	Add DynamicallyAccessedMembers annotations and switch to GetTypeInfo-based APIs in source-gen tests.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/Serialization/PolymorphicTests.cs	Expand [JsonSerializable] registrations needed for source-gen test coverage under analyzers.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/Serialization/JsonSerializerWrapper.SourceGen.cs	Ensure wrapper uses JsonTypeInfo-based serialize/deserialize overloads (trim/AOT-safe).
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/RealWorldContextTests.cs	Update enum converter instantiation to avoid analyzer warnings in source-gen tests.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/JsonSourceGenerationOptionsTests.cs	Mark reflection-heavy assertions with RequiresUnreferencedCode.
src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Tests/JsonSerializerContextTests.cs	Add RequiresUnreferencedCode/RequiresDynamicCode where reflection-based APIs are intentionally exercised.
src/libraries/System.Text.Json/tests/Common/UnsupportedTypesTests.cs	Replace conditional compilation with explicit Requires* annotations for reflection-heavy test paths.
src/libraries/System.Text.Json/tests/Common/UnionTests.cs	Remove populateMissingResolver: true usage and switch to analyzer-friendlier patterns.
src/libraries/System.Text.Json/tests/Common/StructuralJsonTypeClassifierTests.cs	Base options on serializer-under-test defaults to align with source-gen / reflection-disabled configurations.
src/libraries/System.Text.Json/tests/Common/SerializerTests.cs	Replace reflection-based structural comparer with a JsonTypeInfo-based comparer helper.
src/libraries/System.Text.Json/tests/Common/RequiredKeywordTests.cs	Guard reflection-emit dependent test and annotate reflection/dynamic code requirements; reuse wrapper GetTypeInfo.
src/libraries/System.Text.Json/tests/Common/ReferenceHandlerTests/ReferenceHandlerTests.Serialize.cs	Add suppressed, guarded Newtonsoft baseline comparison helper to satisfy analyzers.
src/libraries/System.Text.Json/tests/Common/ReferenceHandlerTests/ReferenceHandlerTests.IgnoreCycles.cs	Add DynamicallyAccessedMembers annotations to reflection-based helper usage.
src/libraries/System.Text.Json/tests/Common/ReferenceHandlerTests/ReferenceHandlerTests.cs	Switch comparisons to the guarded Newtonsoft baseline helper; add CodeAnalysis using.
src/libraries/System.Text.Json/tests/Common/PropertyVisibilityTests.NonPublicAccessors.cs	Add DynamicallyAccessedMembers and adjust enum converter usage for analyzer compatibility.
src/libraries/System.Text.Json/tests/Common/PropertyVisibilityTests.InitOnly.cs	Add DynamicallyAccessedMembers annotations on Type-driven tests.
src/libraries/System.Text.Json/tests/Common/PropertyVisibilityTests.cs	Add DynamicallyAccessedMembers annotations on reflection-driven Type parameters.
src/libraries/System.Text.Json/tests/Common/PolymorphicTests.TypeClassifier.cs	Use Serializer.DefaultOptions to avoid reflection-resolver setup that conflicts with source-gen configurations.
src/libraries/System.Text.Json/tests/Common/PolymorphicTests.CustomTypeHierarchies.cs	Switch equality comparers to JsonTypeInfo-based comparer; add guards for reflection-disabled configurations.
src/libraries/System.Text.Json/tests/Common/PolymorphicTests.cs	Avoid reflection-resolver setup; add DynamicallyAccessedMembers where Activator.CreateInstance is used.
src/libraries/System.Text.Json/tests/Common/NumberHandlingTests.cs	Annotate reflection-heavy helpers and gate NativeAOT-incompatible test sections.
src/libraries/System.Text.Json/tests/Common/NullableAnnotationsTests.cs	Add DynamicallyAccessedMembers annotations for Activator.CreateInstance(Type) usage.
src/libraries/System.Text.Json/tests/Common/MetadataTests.Options.cs	Avoid reflection-based CreateJsonTypeInfo path in favor of metadata services for a known value type.
src/libraries/System.Text.Json/tests/Common/MetadataTests.cs	Add DynamicallyAccessedMembers / RequiresUnreferencedCode annotations around reflection-heavy validation.
src/libraries/System.Text.Json/tests/Common/JsonTestHelper.cs	Annotate reflection-based options comparison helper with RequiresUnreferencedCode.
src/libraries/System.Text.Json/tests/Common/JsonSerializerWrapper.cs	Adjust MakeReadOnly behavior under BUILDING_SOURCE_GENERATOR_TESTS for analyzer compatibility.
src/libraries/System.Text.Json/tests/Common/JsonSchemaExporterTests.cs	Gate reflection-heavy tests and switch to GetTypeInfo-based serialization in helper paths.
src/libraries/System.Text.Json/tests/Common/JsonCreationHandlingTests.Object.cs	Add DynamicallyAccessedMembers and RequiresDynamicCode for reflection/dynamic-type construction.
src/libraries/System.Text.Json/tests/Common/ExtensionDataTests.cs	Add DynamicallyAccessedMembers annotations for reflection-based property access.
src/libraries/System.Text.Json/tests/Common/ConstructorTests/ConstructorTests.ParameterMatching.cs	Add DynamicallyAccessedMembers to generic test helper to satisfy trimming analysis.
src/libraries/System.Text.Json/tests/Common/ConstructorTests/ConstructorTests.Cache.cs	Add DynamicallyAccessedMembers annotations to reflection-heavy generic helpers.
src/libraries/System.Text.Json/tests/Common/CollectionTests/CollectionTests.KeyValuePair.cs	Add DynamicallyAccessedMembers annotations for reflection-based policy instantiation.
src/libraries/System.Text.Json/tests/Common/CollectionTests/CollectionTests.Dictionary.cs	Add Requires* annotations and adjust reflection patterns to be trim/AOT analyzer compatible.
src/libraries/System.Text.Json/tests/Common/CollectionTests/CollectionTests.AsyncEnumerable.cs	Replace reflection-based serialization baselines with wrapper/type-info based calls for source-gen compatibility.

[MichalStrehovsky]

Thank you!

[eiriktsarpalis]

/azp run runtime-nativeaot-outerloop

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[github-actions]

Copilot Code Review

Holistic Assessment

Motivation: Well-justified. Enabling trim/AOT analyzers on the source generator test projects closes a real gap where AOT/trim regressions would only surface in Native AOT outerloop runs (not part of regular PR builds). This directly follows up on #129965.

Approach: Sound and systematic. The PR resolves analyzer warnings using established patterns: options.GetTypeInfo<T>() for trim-safe serialization, [DynamicallyAccessedMembers] annotations where reflection is needed, [ConditionalFact/Theory] for platform-specific skips, [UnconditionalSuppressMessage] with runtime guards for justified suppressions, and JsonStringEnumConverter<TEnum>() over the non-generic variant.

Summary: ✅ LGTM. This is a well-executed, large-but-focused infrastructure improvement across 42 test files. All changes are confined to test code with no product code modifications. The patterns used are consistent with existing conventions. The only minor concern (early returns vs. SkipTestException) was already flagged by the previous inline review and is non-blocking.

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Detailed Findings

Detailed Findings

✅ Analyzer Enablement — Core goal achieved correctly

Removing <EnableTrimAnalyzer>false</EnableTrimAnalyzer> and <EnableAotAnalyzer>false</EnableAotAnalyzer> from both Roslyn 3.11 and 4.4 .csproj files correctly enables the analyzers for the source generator test projects. The .targets file additions (DynamicallyAccessedMembersAttribute, RequiresUnreferencedCodeAttribute, RequiresDynamicCodeAttribute, UnconditionalSuppressMessageAttribute, CompilerLoweringPreserveAttribute) are needed for non-netcoreapp targets.

✅ Source-Gen Wrapper — Trim-safe overloads used correctly

JsonSerializerWrapper.SourceGen.cs consistently replaces JsonSerializer.Serialize<T>(value, options) and JsonSerializer.Deserialize<T>(json, options) calls with their JsonTypeInfo-based counterparts via options.GetTypeInfo<T>(). This is the canonical trim/AOT-safe pattern for System.Text.Json.

The #if BUILDING_SOURCE_GENERATOR_TESTS conditional in JsonSerializerWrapper.cs switching from MakeReadOnly(populateMissingResolver: true) to MakeReadOnly() is correct — in source-gen mode, all types are registered through the context and the reflection fallback should be disabled.

✅ Newtonsoft.Json Baseline Extraction — Clean and well-guarded

The AssertOutputEqualsNewtonsoft helper in ReferenceHandlerTests.Serialize.cs uses PlatformDetection.IsReflectionEmitSupported as a runtime guard (correct since Newtonsoft.Json's serialization APIs are reflection-based). The [UnconditionalSuppressMessage] suppressions are properly justified. The refactoring cleanly removes redundant JsonConvert.SerializeObject calls from individual tests without losing coverage.

✅ PolymorphicEqualityComparer Replacement — Correct structural improvement

Replacing the reflection-based PolymorphicEqualityComparer<T>.Instance (which iterated properties via GetProperties()) with CreateJsonEqualityComparer<T>() that serializes through JsonTypeInfo<T> is trim-safe. The compareRuntimeType parameter preserves the semantic of rejecting objects with differing runtime types.

✅ CustomPolymorphismResolver — Correct dual-mode resolver

The #if BUILDING_SOURCE_GENERATOR_TESTS conditional in CustomPolymorphismResolver that substitutes DefaultJsonTypeInfoResolver with the generated PolymorphicTestsContext_Metadata.Default is the correct approach for making the resolver work in both source-gen and reflection modes.

✅ MetadataTests.Options — Narrowed EmptyContext is sufficient

The EmptyContext.GetTypeInfo change from generic JsonTypeInfo.CreateJsonTypeInfo(type, Options) to only handling typeof(int) is correct for this test's purpose (testing that passing wrong options throws InvalidOperationException). The original implementation used a trim-unsafe API unnecessarily.

✅ StructuralJsonTypeClassifierTests — Instance options correct

Switching from static readonly options with new DefaultJsonTypeInfoResolver() to instance-level options derived from serializerUnderTest.DefaultOptions ensures tests use the correct resolver chain (source-gen or reflection) depending on configuration.

💡 Early Returns vs. SkipTestException — Minor (already flagged)

Some tests that cannot run in source-gen mode use return Task.CompletedTask; instead of throwing a skip exception (e.g., PolymorphicClass_CustomConfigWithNearestAncestorFallback_TestData_Serialization). This was already flagged by the previous inline review. Using throw new SkipException(...) would make test reports more explicit about what was skipped, but this is non-blocking.

Note

This review was generated by GitHub Copilot.

Generated by Code Review for issue #130132 · ● 67.7M · ◷

[eiriktsarpalis]

/azp run runtime-nativeaot-outerloop

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[Copilot]

Pull request overview

Copilot reviewed 42 out of 42 changed files in this pull request and generated 4 comments.

[krwq]

LGTM assuming nothing blocking comes up from comments but doesn't look like