feat(enhanced): comprehensive ProvideSharedPlugin test coverage (#3969)

Co-authored-by: Claude <[email protected]>

Author: ScriptedAlchemy

.changeset/comprehensive-consume-shared-tests.md

@@ -0,0 +1,16 @@
+---
+"@module-federation/enhanced": patch
+---
+
+test: implement comprehensive test coverage for ConsumeSharedPlugin
+
+- Add 70+ comprehensive tests for createConsumeSharedModule method covering all critical business logic
+- Implement tests for import resolution logic including error handling and direct fallback regex matching
+- Add comprehensive requiredVersion resolution tests for package name extraction and version resolution
+- Implement include/exclude version filtering tests with fallback version support
+- Add singleton warning generation tests for version filters as specified
+- Implement package.json reading error scenarios and edge case handling
+- Add apply method tests for plugin registration logic and hook setup
+- Achieve test coverage parity with ProvideSharedPlugin (70+ tests each)
+
+This addresses the requirement for "immense test coverage for consume share plugin and provide share plugin to cover all its very complex logic" and ensures comprehensive testing of multi-stage module resolution, layer matching, version filtering, and error handling.

.changeset/comprehensive-provide-shared-tests.md

@@ -0,0 +1,16 @@
+---
+"@module-federation/enhanced": patch
+---
+
+test: add comprehensive test coverage for ProvideSharedPlugin
+
+- Add 73 comprehensive tests covering all critical business logic and edge cases
+- Implement complete shouldProvideSharedModule method coverage (15 tests) for version filtering with semver validation
+- Add provideSharedModule method tests (16 tests) covering version resolution, request pattern filtering, and warning generation
+- Implement module matching and resolution stage tests (20 tests) for multi-stage resolution logic
+- Validate business rules: warnings only for version filters with singleton, not request filters
+- Cover all critical private methods with proper TypeScript handling using @ts-ignore
+- Fix container utils mock for dependency factory operations
+- Add performance and memory usage tests for large-scale scenarios
+
+This ensures comprehensive test coverage for ProvideSharedPlugin's complex module sharing logic and prevents regressions.

.changeset/pr9-enhanced-layer-support.md

@@ -0,0 +1,14 @@
+---
+"@module-federation/enhanced": minor
+---
+
+feat: implement enhanced layer support with issuerLayer fallback logic
+
+- Add issuerLayer parameter support throughout ConsumeSharedPlugin and related modules
+- Implement issuerLayer fallback pattern in module resolution (tries issuerLayer first, then falls back to undefined)
+- Add createLookupKeyForSharing utility to generate layer-aware lookup keys (e.g., "(client)react")
+- Support layer-specific module sharing configuration with proper precedence rules
+- Add comprehensive unit tests for issuerLayer fallback behavior and utility functions
+- Fix test infrastructure issues and improve test assertions for better CI stability
+
+This completes PR9: Enhanced Layer Support as defined in the incremental PR plan, enabling more granular control over shared module resolution based on issuer layers.