phase 1 refactoring

Author: dboskovic

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+    "editor.defaultFormatter": "biomejs.biome"
+}

AGENT.md

@@ -1,10 +1,13 @@
 # PapaParse Agent Guide
 
+ALWAYS REFERENCE V6_REFACTOR.md before beginning refactor work.
+ALWAYS UPDATE V6_REFACTOR.md with any progress you've made.
+
 ## Commands
-- **Test**: `npm test` (all), `npm run test-node` (node only), `npm run test-mocha-headless-chrome` (headless browser)
-- **Lint**: `npm run lint` 
-- **Build**: `npm run build` or `grunt build` (creates minified version)
-- **Development server**: `node tests/test.js` (for browser testing)
+- **Test**: `bun test` (all), `bun run test-node` (node only), `bun run test-mocha-headless-chrome` (headless browser)
+- **Lint**: `bun run lint`
+- **Build**: `bun run build` or `grunt build` (creates minified version)
+- **Development server**: `bun tests/test.js` (for browser testing)
 - **Modern Development**: Uses bun for modern TypeScript development
 
 ## Architecture

V6_REFACTOR.md

@@ -1,5 +1,35 @@
 # PapaParse V6 Refactoring Plan
 
+## 🚀 Implementation Progress
+
+**Current Status: Phase 1 Complete ✅**
+
+- ✅ **Phase 1: Foundation & Performance Infrastructure** (100% Complete)
+- 🚧 **Phase 2: Core Parsing Engine** (Ready to begin)
+- ⏳ **Phase 3: Heuristics & Algorithms** (Planned)
+- ⏳ **Phase 4: Streaming Infrastructure** (Planned)
+- ⏳ **Phase 5: Core Functions** (Planned)
+- ⏳ **Phase 6: Workers & Concurrency** (Planned)
+- ⏳ **Phase 7: Plugin System** (Planned)
+- ⏳ **Phase 8: Public API & Compatibility** (Planned)
+
+### Recent Achievements (Phase 1)
+- ✅ Complete TypeScript foundation with exact legacy compatibility types
+- ✅ Runtime-mutable constants system preserving legacy behavior
+- ✅ Comprehensive utility functions extracted from legacy implementation
+- ✅ Performance benchmark harness for regression testing
+- ✅ Golden output snapshots for compatibility validation
+- ✅ API surface reflection testing for singleton consistency
+- ✅ Full CI testing infrastructure with npm scripts
+- ✅ Foundation tests passing: `bun run ci:foundation`
+
+### Next Steps (Phase 2)
+Ready to begin Core Parsing Engine implementation:
+- Lexer implementation with quote state machine
+- Parser implementation with row assembly
+- Error handling system
+- Parser handle for orchestration
+
 ## Overview
 This document outlines the migration plan from the legacy single-file format (`legacy/papaparse.js`) to a modern, modular TypeScript architecture while maintaining 100% API compatibility and ensuring all tests pass.
 
@@ -256,15 +286,17 @@ export function escapeRegExp(string: string): string // line 1409
 
 ## Implementation Checklist
 
-### Foundation & Safety Infrastructure
-- [ ] Create CI performance benchmark harness
-- [ ] Implement golden output snapshots for regression testing
-- [ ] Set up API surface reflection testing
-- [ ] Configure TypeScript with `"target": "es5", "module": "es2015"`
-- [ ] Implement exact legacy types in `src/types/` for public API
-- [ ] Create stricter internal types for development
-- [ ] Set up runtime-mutable constants (`src/constants/`)
-- [ ] Create utility functions (`src/utils/`)
+### Foundation & Safety Infrastructure ✅ COMPLETED
+- [x] Create CI performance benchmark harness
+- [x] Implement golden output snapshots for regression testing
+- [x] Set up API surface reflection testing
+- [x] Configure TypeScript with `"target": "es2018", "module": "commonjs"` (updated for compatibility)
+- [x] Implement exact legacy types in `src/types/` for public API
+- [x] Create stricter internal types for development
+- [x] Set up runtime-mutable constants (`src/constants/`)
+- [x] Create utility functions (`src/utils/`)
+- [x] Create CI testing infrastructure with npm scripts
+- [x] Test foundation infrastructure (`bun run ci:foundation` passing)
 
 ### Core Engine Implementation
 - [ ] **Lexer** (`src/core/lexer.ts`) - Pure byte/character scanning with tight loops
@@ -427,10 +459,10 @@ src/
 - [ ] **Memory Profiling**: Verify streaming doesn't increase memory usage
 
 ### API Compatibility Protection  
-- [ ] **Golden Output Snapshots**: Freeze current parser results as test fixtures
-- [ ] **Reflection Testing**: `Object.keys(Papa)` must match between versions
-- [ ] **Singleton Reference Testing**: `require('papaparse').parse === require('papaparse').parse`
-- [ ] **Edge Case Preservation**: `Papa.parse('', {dynamicTyping: true}).data` returns `[[""]]`
+- [x] **Golden Output Snapshots**: Freeze current parser results as test fixtures
+- [x] **Reflection Testing**: `Object.keys(Papa)` must match between versions
+- [x] **Singleton Reference Testing**: `require('papaparse').parse === require('papaparse').parse`
+- [x] **Edge Case Preservation**: `Papa.parse('', {dynamicTyping: true}).data` returns `[[""]]`
 
 ### Breaking Change Traps to Avoid
 - [ ] Worker blob URL generation must preserve `Papa.WORKER_ID` global
@@ -452,4 +484,57 @@ src/
 - [ ] **Test Coverage**: 100% existing test pass rate
 - [ ] **Bundle Impact**: Core bundle size reduction, optional features tree-shakable
 
-This enhanced plan incorporates Oracle guidance for enterprise-grade reliability while enabling long-term maintainability improvements. The modular architecture with train-case naming provides a solid foundation for future CSV parsing innovations.
+## 🧪 CI Testing Infrastructure (Phase 1 Complete)
+
+The following testing infrastructure has been implemented and is ready for use:
+
+### Performance Benchmarking
+```bash
+bun run ci:benchmark        # Run performance benchmarks
+```
+- Micro-benchmark harness tracking rows/second for 50MB+ files
+- Memory usage profiling during parsing
+- Regression detection (modern implementation must be within 5% of legacy speed)
+- Automated test data generation for stress testing
+
+### Golden Output Snapshots
+```bash
+bun run ci:snapshots:generate  # Generate baseline snapshots from legacy
+bun run ci:snapshots:validate  # Validate modern implementation against snapshots
+```
+- Freeze current parser results as regression test fixtures
+- 10+ standard test cases covering edge cases (quotes, line breaks, unicode, etc.)
+- Automated comparison with detailed diff reporting
+- Ensures bit-for-bit compatibility between implementations
+
+### API Surface Reflection Testing
+```bash
+bun run ci:api-test           # Run API compatibility tests
+```
+- Validates `Object.keys(Papa)` matches exactly between versions
+- Tests singleton reference consistency
+- Verifies mutable properties (LocalChunkSize, RemoteChunkSize) work correctly
+- Checks edge cases like `Papa.parse('', {dynamicTyping: true}).data` returns `[[""]]`
+
+### Foundation Testing
+```bash
+bun run ci:foundation         # Test basic TypeScript infrastructure ✅ PASSING
+bun run ci:all               # Run complete CI test suite
+```
+- TypeScript compilation validation
+- Utility function testing
+- Constants system testing
+- Module import/export verification
+
+### npm Scripts Available
+- `bun run ci:foundation` - Foundation infrastructure tests (✅ passing)
+- `bun run ci:benchmark` - Performance regression testing
+- `bun run ci:snapshots:generate` - Create baseline snapshots
+- `bun run ci:snapshots:validate` - Validate compatibility
+- `bun run ci:api-test` - API surface testing
+- `bun run ci:all` - Complete test suite
+- `bun run refactor:test` - Alias for foundation tests
+
+This enhanced plan incorporates Oracle guidance for enterprise-grade reliability while enabling long-term maintainability improvements. The modular architecture provides a solid foundation for future CSV parsing innovations.
+
+**Phase 1 Status: ✅ COMPLETE - Ready for Phase 2 implementation**

bun.lock

@@ -6,6 +6,7 @@
       "devDependencies": {
         "@biomejs/biome": "2.1.2",
         "@types/bun": "latest",
+        "@types/papaparse": "^5.3.16",
         "chai": "^4.2.0",
         "connect": "^3.3.3",
         "eslint": "^4.19.1",
@@ -15,8 +16,6 @@
         "mocha-headless-chrome": "^4.0.0",
         "open": "7.0.0",
         "serve-static": "^1.7.1",
-      },
-      "peerDependencies": {
         "typescript": "^5",
       },
     },
@@ -44,6 +43,8 @@
 
     "@types/node": ["@types/[email protected]", "", { "dependencies": { "undici-types": "~7.8.0" } }, "sha512-ut5FthK5moxFKH2T1CUOC6ctR67rQRvvHdFLCD2Ql6KXmMuCrjsSsRI9UsLCm9M18BMwClv4pn327UvB7eeO1w=="],
 
+    "@types/papaparse": ["@types/[email protected]", "", { "dependencies": { "@types/node": "*" } }, "sha512-T3VuKMC2H0lgsjI9buTB3uuKj3EMD2eap1MOuEQuBQ44EnDx/IkGhU6EwiTf9zG3za4SKlmwKAImdDKdNnCsXg=="],
+
     "@types/react": ["@types/[email protected]", "", { "dependencies": { "csstype": "^3.0.2" } }, "sha512-AwAfQ2Wa5bCx9WP8nZL2uMZWod7J7/JSplxbTmBQ5ms6QpqNYm672H0Vu9ZVKVngQ+ii4R/byguVEUZQyeg44g=="],
 
     "@types/yauzl": ["@types/[email protected]", "", { "dependencies": { "@types/node": "*" } }, "sha512-oJoftv0LSuaDZE3Le4DbKX+KS9G36NzOeSap90UIK0yMA/NhKJhqlSGtNDORNRaIbQfzjXDrQa0ytJ6mNRGz/Q=="],

.eslintrc.js renamed to legacy/.eslintrc.js

@@ -39,6 +39,7 @@
   "devDependencies": {
     "@biomejs/biome": "2.1.2",
     "@types/bun": "latest",
+    "@types/papaparse": "^5.3.16",
     "chai": "^4.2.0",
     "connect": "^3.3.3",
     "eslint": "^4.19.1",
@@ -53,10 +54,19 @@
   "scripts": {
     "lint": "eslint --no-ignore legacy/papaparse.js Gruntfile.js .eslintrc.js 'tests/**/*.js'",
     "build": "grunt build",
+    "build-ts": "tsc",
     "test-browser": "node tests/test.js",
     "test-mocha-headless-chrome": "node tests/test.js --mocha-headless-chrome",
     "test-node": "mocha tests/node-tests.js tests/test-cases.js",
-    "test": "npm run lint && npm run test-node && npm run test-mocha-headless-chrome"
+    "test": "npm run lint && npm run test-node && npm run test-mocha-headless-chrome",
+    "ci": "bun run src/ci/index.ts",
+    "ci:foundation": "bun run src/ci/index.ts foundation",
+    "ci:benchmark": "bun run src/ci/index.ts benchmark",
+    "ci:snapshots:generate": "bun run src/ci/index.ts generate-snapshots",
+    "ci:snapshots:validate": "bun run src/ci/index.ts validate-snapshots",
+    "ci:api-test": "bun run src/ci/index.ts api-test",
+    "ci:all": "bun run src/ci/index.ts all",
+    "refactor:test": "npm run ci:foundation"
   },
   "private": true
 }