Keep the service key when resolving keyed services via service location

[jeremydmiller]

Problem

Fixes the root cause of JasperFx/wolverine#2878: keyed services and opaque (lambda-factory) registrations each work in isolation, but not together in the same handler.

When anything in a generated method forces the scoped-IServiceProvider "service location" path — a dependency that injects IServiceProvider directly, or an opaque lambda registration like the ones the MS Graph SDK adds (AddScoped<IFoo>(_ => …)) — every sibling dependency in that method is resolved through GetServiceFromScopedContainerFrame. That frame always emitted:

GetRequiredService<T>(provider)

and dropped the key, so a keyed service dragged onto that path either threw (No service for type T has been registered) or resolved the wrong registration. The string GetRequiredKeyedService appeared nowhere in the generated output. The inline [FromKeyedServices] constructor path was fine — only the service-location frame discarded the key.

Diagnosis credit to @BlackChepo in the issue thread.

Fix

Thread the service key through GetServiceFromScopedContainerFrame and emit the keyed call when the descriptor is keyed:

GetRequiredKeyedService<T>(provider, key)   // key rendered via CodeFormatter.Write

Both call sites now pass the key:

• ServiceLocationPlan.CreateVariable (keyed opaque registrations)
• ServiceCollectionServerVariableSource.useServiceProvider (keyed services dragged onto location by a sibling opaque dependency)

Non-keyed resolution is byte-for-byte unchanged (the new constructor parameter defaults to null).

Tests

CodegenTests/Services/keyed_service_location.cs reproduces the bug the way Wolverine generates a handler — a MethodCall to a handler whose parameters are a [FromKeyedServices("blue")] IWidget plus an opaque IScopedLambda sibling that forces service location:

• generated code uses GetRequiredKeyedService<IWidget>(provider, "blue") for both the keyed-concrete and keyed-opaque registrations;
• end-to-end: the generated harness compiles and resolves the keyed service at runtime (threw No service for type IWidget before the fix).

All 3 fail before the fix and pass after. Full suite green locally: CodegenTests 346/346, CoreTests 439/439 (net9.0).

Note: consuming repos (Wolverine, Marten, …) pick this up with the next JasperFx release; #2878 itself is in Wolverine.

🤖 Generated with Claude Code