MCP Debugger

# Task: Complete DAP Proxy Worker Migration to Production ## Context The DAP Proxy Worker refactoring to use the Adapter Policy pattern is 95% complete but **not deployed**. The refactored version exists at `src/proxy/dap-proxy-worker-refactored.ts` while production still uses the old `src/proxy/dap-proxy-worker.ts`, causing 0% test coverage (326 uncovered lines). ## Current State - ✅ **Refactored version exists** with policy pattern implemented - ✅ **Build succeeds** with no TypeScript errors - ❌ **Not deployed** - production uses old version - ❌ **5 hardcoded checks remain** in refactored version - ❌ **No test coverage** for refactored version ## Objectives 1. Complete the refactoring by removing remaining hardcoded checks 2. Deploy the refactored version to production 3. Add comprehensive test coverage 4. Achieve the targeted 7.2% overall coverage improvement ## Required Steps ### Phase 1: Complete Refactoring (30 minutes) - [ ] Remove 5 remaining hardcoded `js-debug` checks from `dap-proxy-worker-refactored.ts` - Lines with `if (adapterCommand.includes('js-debug'))` - Replace with policy method calls - [ ] Ensure all language detection uses policy pattern - [ ] Verify no direct language references remain ### Phase 2: Deploy to Production (1 hour) - [ ] Update all imports that reference old `dap-proxy-worker.ts` - Check `src/proxy/proxy-manager.ts` - Check `src/session/` files - Search for all import statements: `from './dap-proxy-worker'` - [ ] Rename files: - [x] ~~Keep `dap-proxy-worker-legacy.ts` as backup~~ (Removed - file was unused) - [ ] Move `dap-proxy-worker.ts` to `dap-proxy-worker-old.ts` - [ ] Move `dap-proxy-worker-refactored.ts` to `dap-proxy-worker.ts` - [ ] Update any remaining import paths - [ ] Run build to ensure no errors: `pnpm build` - [ ] Run existing tests to ensure nothing breaks: `pnpm test` ### Phase 3: Add Test Coverage (2-3 hours) Create comprehensive tests at `tests/unit/proxy/dap-proxy-worker.test.ts`: #### Core Functionality Tests - [ ] Test initialization with different adapter policies - [ ] Test policy selection based on adapter command - [ ] Test state management through policy - [ ] Test command routing to policy methods #### Policy Integration Tests - [ ] Test JavaScript policy integration - Command queueing behavior - State transitions - Event handling - [ ] Test Python policy integration - No queueing behavior - Direct command passing - [ ] Test Mock policy for testing scenarios - [ ] Test Default policy fallback #### Error Handling Tests - [ ] Test invalid adapter command handling - [ ] Test policy method exceptions - [ ] Test state corruption recovery - [ ] Test timeout scenarios #### Edge Cases - [ ] Test switching between policies (should not be allowed) - [ ] Test concurrent command handling - [ ] Test cleanup and disposal ### Phase 4: Verify Coverage Improvement (30 minutes) - [ ] Run coverage analysis: `pnpm test:coverage` - [ ] Check specific file coverage: `pnpm test:coverage:analyze` - [ ] Verify `dap-proxy-worker.ts` coverage increased from 0% to 80%+ - [ ] Confirm overall coverage increased by ~7.2% - [ ] Document coverage improvements ### Phase 5: Final Validation (30 minutes) - [ ] Test JavaScript debugging with real scenario - [ ] Test Python debugging with real scenario - [ ] Verify no regression in functionality - [ ] Update documentation ## Success Criteria ✅ No hardcoded language checks in proxy worker ✅ Refactored version deployed to production ✅ Test coverage ≥80% for dap-proxy-worker.ts ✅ Overall project coverage increased by ~7% ✅ All existing functionality preserved ✅ JavaScript and Python debugging still work ## Code Locations - **Main file**: `src/proxy/dap-proxy-worker-refactored.ts` - ~~**Legacy backup**: `src/proxy/dap-proxy-worker-legacy.ts`~~ (Removed - was unused) - **Current production**: `src/proxy/dap-proxy-worker.ts` - **Import locations**: Search for `from './dap-proxy-worker'` - **Test file to create**: `tests/unit/proxy/dap-proxy-worker.test.ts` ## Verification Commands ```bash # Build verification pnpm build # Test execution pnpm test # Coverage analysis pnpm test:coverage pnpm test:coverage:analyze # Search for remaining hardcoded checks grep -n "js-debug" src/proxy/dap-proxy-worker-refactored.ts # Find all imports of old proxy worker grep -r "from './dap-proxy-worker'" src/ ``` ## Risk Mitigation - ~~Keep `dap-proxy-worker-legacy.ts` as emergency rollback~~ (File removed - was unused) - Test extensively before removing old files - Create git commit after each phase for easy rollback - Monitor debug sessions after deployment ## Expected Impact - **Coverage**: From 53.8% → ~61% overall - **Architecture**: Clean, extensible policy pattern - **Maintainability**: Easy to add new language support - **Technical Debt**: Eliminated language-specific hardcoding ## Notes - The refactoring work is excellent but incomplete - The 0% coverage mystery is solved - wrong file in production - This migration will finally realize the benefits of the refactoring