Fix keyOf to handle unresolved type variables

[adrw]

Summary

• Fix keyOf<T>() to fall back to the erased class (T::class.java) when the resolved TypeLiteral contains unresolved TypeVariables
• Fully specified generic types (e.g., keyOf<List<String>>()) still use TypeLiteral for proper generic type preservation

Problem

PR #3668 changed keyOf from Key.get(T::class.java, ...) to Key.get(object : TypeLiteral<T>() {}, ...). This breaks callers that pass generic types containing non-reified type parameters from enclosing classes, such as:

class BatchReceiverModule<R : BatchReceiver<T>, T : Any> : KAbstractModule() {
  override fun configure() {
    // T is a class type parameter, not reified — TypeLiteral captures it as TypeVariable
    val key = keyOf<DecodingBatchCloudEventReceiver<T>>(Names.named("..."))
  }
}

Guice rejects the resulting key with KeyNotFullySpecified because DecodingBatchCloudEventReceiver<T> contains an unresolved TypeVariable.

This breaks InjectorTest in cash-server's Yolodex service (and any other service using BatchReceiverModule, SuspendingBatchReceiverModule, or SuspendingReceiverModule).

Fix

Added a containsTypeVariable() extension on java.lang.reflect.Type that recursively checks for TypeVariable instances. keyOf now checks the TypeLiteral's type — if it contains any type variables, it falls back to the old erased-class behavior. Otherwise, it uses the TypeLiteral for full generic type preservation.

Test plan

• Verified InjectorTest in cash-server Yolodex service fails with the current Misk version (2026.02.14.023725-1db1eee) — 3/3 tests fail with KeyNotFullySpecified
• Verified all 48/48 Yolodex tests pass with this fix applied via local.properties include

[Copilot]

Pull request overview

This PR fixes a regression in keyOf<T>() introduced in PR #3668, where changing from T::class.java to TypeLiteral broke modules that use generic class type parameters (non-reified). The fix adds runtime detection of unresolved TypeVariables and falls back to the erased class when needed, while still preserving full generic type information for fully-specified types.

Changes:

• Modified keyOf to conditionally use TypeLiteral or erased class based on whether unresolved type variables are present
• Added containsTypeVariable() extension function on Type to recursively detect TypeVariable instances
• Added comprehensive test coverage for both the fix and the helper function

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
misk-inject/src/main/kotlin/misk/inject/Guice.kt	Implements conditional type handling in keyOf and adds containsTypeVariable() helper function
misk-inject/src/test/kotlin/misk/inject/KeyOfTest.kt	Comprehensive test suite covering simple types, fully-specified generics, unresolved type variables, and the containsTypeVariable() function
misk-inject/api/misk-inject.api	Exposes new containsTypeVariable function as public API

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