source-map-parser-mcp: Instructions file for GitHub Copilot

Source Map Parser MCP Server

Always reference these instructions first and fallback to search or bash commands only when you encounter unexpected information that does not match the info here.

This is a TypeScript MCP (Model Context Protocol) server for parsing JavaScript source maps. It provides tools to map minified JavaScript error stack traces back to their original source code locations.

Working Effectively

Bootstrap and Build (REQUIRED)

• ALWAYS run these commands in order to get started:
  • npm install -- takes ~1 second. Dependencies are already cached.
  • npm run build -- takes ~4-5 seconds total. NEVER CANCEL. Set timeout to 30+ seconds.
  • The build process includes:
    • npm run build:vite (Vite build ~1.3 seconds)
    • npx -y repomix (documentation generation ~3 seconds)

Testing

• npm run test:ci -- takes ~11 seconds total. NEVER CANCEL. Set timeout to 30+ seconds.
  • Memory cache tests: 8 tests pass in <1 second
  • Client test: Currently times out after 10 seconds (known issue - integration test configuration)
  • Note: The client test timeout does NOT indicate the server is broken - it's a test configuration issue
• Do NOT attempt to fix the client test timeout unless specifically asked - it's not critical to functionality

Running the Server

• Method 1 (Development): npx tsx src/main.ts
• Method 2 (Built): node dist/main.es.js
• Method 3 (NPX): npx -y source-map-parser-mcp@latest
• The server runs as an MCP stdio server and will wait for MCP client connections

Environment Configuration

• SOURCE_MAP_PARSER_RESOURCE_CACHE_MAX_SIZE - Max memory cache (default: 200MB)
• SOURCE_MAP_PARSER_CONTEXT_OFFSET_LINE - Context lines around errors (default: 1)

Validation

ALWAYS Test These Scenarios After Changes:

1. Build Validation:
   • npm run build must complete successfully
   • Check that dist/main.es.js and dist/main.cjs.js are created
   • Verify no TypeScript compilation errors