Move circular reference handling from ResolverChain to NullableResolver #61

Description

ResolverChain currently contains both circular-reference detection and circular-reference handling. The handleCircularReference method decides whether to return null or throw SomeCircularReferenceException based on NullableStrategy. This couples the core resolution chain with nullable-specific strategy behavior.

The goal is to simplify ResolverChain so it only detects circular references and always throws SomeCircularReferenceException. NullableResolver will then catch the exception when resolving non-null instances and decide whether to return null based on the active NullableStrategy.

• Scope and constraints

  • ResolverChain must retain detectCircularReference and the resolution stack
  • ResolverChain must no longer receive NullableStrategy via its constructor
  • NullableResolver must handle SomeCircularReferenceException when resolving non-null values
  • Non-nullable circular references must still throw SomeCircularReferenceException
  • All existing tests must continue to pass

• References

  • src/main/kotlin/dev/appoutlet/some/core/ResolverChain.kt
  • src/main/kotlin/dev/appoutlet/some/resolver/NullableResolver.kt
  • src/main/kotlin/dev/appoutlet/some/Some.kt

Scope

In scope:

• Removing handleCircularReference and nullableStrategy from ResolverChain
• Updating ResolverChain to always throw SomeCircularReferenceException on circular references
• Updating NullableResolver to catch SomeCircularReferenceException and decide whether to return null or re-throw based on the active NullableStrategy
• Updating Some.kt and TestHelpers.kt to stop passing NullableStrategy to ResolverChain

Out of scope:

• Changing the behavior of NullableStrategy variants
• Changing the circular-reference detection algorithm in ResolverChain

Acceptance criteria

• ResolverChain no longer contains handleCircularReference method
• ResolverChain no longer accepts nullableStrategy as a constructor parameter
• ResolverChain throws SomeCircularReferenceException for all detected circular references
• NullableResolver catches SomeCircularReferenceException when calling chain.resolve(nonNullType) and decides whether to return null or re-throw based on the active NullableStrategy
• Some.kt and TestHelpers.kt no longer pass NullableStrategy to ResolverChain
• All existing tests pass, including CircularReferenceIntegrationTest

Additional information

The current implementation short-circuits in ResolverChain.resolve() before resolvers are invoked when a circular reference is detected. After this refactor, ResolverChain should detect and throw for all circular references, while NullableResolver handles the exception when resolving non-null values for nullable types.