TLDR

Complete RAG (Retrieval-Augmented Generation) system implementation with HippoRAG, Milvus vector database integration, and automated file watching capabilities. Fixes TypeScript module resolution issues and adds comprehensive test coverage.

Dive Deeper

This PR introduces a full-featured RAG system that enables intelligent code retrieval and context-aware responses. The implementation includes:

Core Components Added:

• MilvusCodeStorage: Vector database integration for storing code chunks with embeddings
• HippoRAG: High-level API wrapper for RAG operations
• RAGService: Service layer for application integration
• FileWatcherService: Automatic RAG updates when files change
• retrieve-code & update-rag: CLI tools for manual RAG operations

Technical Improvements:

• Fixed ECMAScript module resolution by adding .js extensions to all TypeScript imports
• Resolved test mocking issues in MilvusCodeStorage tests
• Added proper error handling for undefined values in collection operations
• Updated system prompt to include RAG integration instructions

Architecture:

• Uses Milvus as the vector database for semantic code search
• Implements chunked code storage with metadata
• Provides both programmatic API and CLI tools
• Includes automated file watching for real-time updates

Reviewer Test Plan

To validate this change works correctly:

1. Run the test suite:

   npm run test --workspace=packages/core --if-present -- --testNamePattern="MilvusCodeStorage"
   npm run test --workspace=packages/core --if-present -- --testNamePattern="HippoRAG"
   npm run test --workspace=packages/core --if-present -- --testNamePattern="RAGService"

2. Test the RAG tools:

   # Test retrieve functionality
   node -e "import('./packages/core/src/rag/index.js').then(async ({ retrieveCode }) => { console.log(await retrieveCode('function declaration', 3)); })"
   
   # Test update functionality
   node -e "import('./packages/core/src/rag/index.js').then(async ({ updateRag }) => { await updateRag('test.ts', 'const test = () => console.log(\"hello\");'); console.log('Updated'); })"

3. Integration test:

   • Create a test file with some TypeScript code
   • Use the file watcher to verify automatic updates
   • Query for relevant code snippets

Testing Matrix

Linked issues / bugs

• Resolves TypeScript module resolution issues with .js extensions
• Fixes undefined value handling in Milvus collection operations
• Addresses missing RAG components in the codebase
• Closes potential runtime errors in vector database interactions