Refactor Coercer Caching to Use Grape::Util::Cache

[ericproulx]

Refactor Coercer Caching to Use Grape::Util::Cache

Summary

This PR refactors the coercer caching mechanism to use the standardized Grape::Util::Cache pattern instead of manual cache management. This improves code consistency, maintainability, and follows the existing patterns used throughout the Grape codebase.

Fix #2515

Changes

Core Refactoring

• Replaced manual cache management with Grape::Util::Cache singleton pattern
• Moved type mappings to dedicated cache classes:
  • Grape::DryTypes::StrictCache - handles strict type mappings
  • Grape::DryTypes::ParamsCache - handles params type mappings
• Simplified build_coercer method by removing manual cache key generation and mutex-based synchronization
• Created CoercerCache class that extends Grape::Util::Cache for coercer instances

Code Improvements

• Centralized type mappings in cache classes, making them easier to maintain and extend
• Removed manual cache variables (@__cache and @__cache_write_lock) from Types module
• Simplified PrimitiveCoercer to use centralized cache classes instead of maintaining its own mappings
• Updated ArrayCoercer to use cache classes directly instead of scope-based lookup

Documentation Updates

• Updated dry-types documentation links from version 1.2 to main (current documentation)
• Limited Dry.Types() inclusion to only what Grape uses (:params, :coercible, :strict)

Test Updates

• Removed tests for internal cache variables (no longer needed)
• Updated test expectations to use new cache class structure
• Simplified cache testing to verify behavior rather than implementation details

Benefits

1. Consistency: Uses the same caching pattern as other parts of Grape (e.g., PartsCache, PatternCache, JoinedSpaceCache)
2. Maintainability: Centralized type mappings make it easier to add new types or modify existing ones
3. Simplicity: Removes manual mutex synchronization and cache key generation
4. Performance: Singleton pattern ensures efficient memory usage and thread-safe access

Files Changed

• lib/grape/dry_types.rb - Added StrictCache and ParamsCache classes
• lib/grape/validations/types.rb - Refactored caching to use CoercerCache
• lib/grape/validations/types/array_coercer.rb - Updated to use cache classes
• lib/grape/validations/types/dry_type_coercer.rb - Simplified to use cache classes
• lib/grape/validations/types/primitive_coercer.rb - Refactored to use centralized cache
• spec/grape/validations/types/primitive_coercer_spec.rb - Updated test expectations
• spec/grape/validations/types_spec.rb - Simplified cache tests

Testing

All existing tests pass. The refactoring maintains backward compatibility while improving the internal implementation.