[ipjohnson]

What changed

This adds DM0026, an analyzer that reports [SingletonService], [ScopedService] and [TransientService] attributes without As = typeof(...). It is off by default. It also adds a code fix that writes the type the generator infers now.

ServiceTypeAnalyzer is in the generator assembly. It calls ServiceTypeInference and passes the inferred type to the fix in the diagnostic's properties. It passes the type only when typeof of it, bound at the attribute, reads back as the same type. ServiceTypeCodeFixProvider is in a new DependencyModules.CodeFixes project. That project references only Roslyn and is packed beside the generator in analyzers/dotnet/cs. scripts/verify-packages.sh checks that the DLL is in the package and that a consumer build with DM0026 set to error fails with DM0026. website/reference/diagnostics.md documents DM0026.

Closes #124. Part of #122.

Why

Projects that want every registration written out can turn DM0026 on and apply the fix, including Fix All, without changing what the container gets. The code fix is a separate assembly because a generator assembly must not reference Microsoft.CodeAnalysis.Workspaces (RS1038).

How it was tested

• dotnet test tests/DependencyModules.Tests -c Release --filter "ServiceTypeCodeFixTests|CodeFixAssemblyTests|PublicApiTests|ServiceTypeInference" passes 50 tests on net8.0 and net10.0.
• ApplyingEveryFix_LeavesTheRegistrationsUnchanged builds the module, applies all 12 fixes, builds it again, and compares the service type, lifetime, key and implementation type of each registration.
• ./scripts/verify-packages.sh passes for net8.0 and net10.0.
• dotnet csharpier check . is clean.
• dotnet pack lists analyzers/dotnet/cs/DependencyModules.CodeFixes.dll, and the nuspec has no dependencies.

Review guide

Start with src/DependencyModules.SourceGenerator/ServiceTypeAnalyzer.cs, mainly WritableServiceType, which decides when a fix is offered. Then read src/DependencyModules.CodeFixes/ServiceTypeCodeFixProvider.cs, mainly WithAs, which edits only the argument list. The tests are in tests/DependencyModules.Tests/GeneratorTests/ServiceTypeCodeFixTests.cs.

To check by hand, open a project that uses the packed package in Visual Studio or Rider, set dotnet_diagnostic.DM0026.severity = warning, and apply the fix and Fix All. No IDE was run for this change.

Answers to the item's questions:

• The packed code fix DLL references only Roslyn, System.Composition, System.Collections.Immutable and netstandard. CodeFixAssemblyTests loads it in a context that refuses every other assembly, so an IDE should load it without a FileNotFoundException for a sibling DLL.
• The analyzer matches the attribute by symbol and As by its written name, the same check the generator uses. Aliased and fully qualified attributes are found and fixed.

Notes:

• ServiceTypeCodeFixTests.cs adds four xUnit1051 warnings per target framework. Those calls do not pass TestContext.Current.CancellationToken.
• A keyed factory method generates code that fails with CS1503. This is an existing generator bug. The round-trip test leaves the key off that factory, and a follow-up step tracks the bug.
• ServiceModelUtility.GetTypeDeclarationDefinition changed from private to internal so the analyzer can call it.

🤖 Generated with Claude Code

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