# JavaScript Debugging Investigation Summary

## Current Status
JavaScript debugging is entering error state when starting, while Python debugging works perfectly.

## Timeline
- **Commit baecf98**: JavaScript debugging "FULLY WORKING" 
- **Commits 749fd55 & c55a566**: Refactored to policy-based architecture
- **Current**: JavaScript debugging broken

## Investigation Findings

### Architecture Analysis
1. ✅ **JsDebugAdapterPolicy exists** with performHandshake implementation
2. ✅ **selectPolicy correctly maps** 'javascript' to JsDebugAdapterPolicy  
3. ✅ **performHandshake is called** in session-manager-operations.ts
4. ✅ **Imports are correct** in both files
5. ✅ **js-debug vendor files exist** at the expected location

### What Changed
The refactoring moved JavaScript-specific handshake code from being inline in `session-manager-operations.ts` to the `JsDebugAdapterPolicy.performHandshake()` method.

**Before (working):**
```typescript
// Direct implementation in session-manager-operations.ts
if (session.language === 'javascript') {
  // Initialize with supportsStartDebuggingRequest
  await pm.sendDapRequest('initialize', {
    clientID: 'mcp',
    adapterID: 'javascript',
    // ... full handshake sequence
  });
}
```

**After (broken):**
```typescript
// Delegated to policy
const policy = this.selectPolicy(session.language);
if (policy.performHandshake) {
  await policy.performHandshake(context);
}
```

## Hypothesis
The issue might be:
1. The handshake context is not being passed correctly
2. The performHandshake implementation in JsDebugAdapterPolicy has a bug
3. Error handling is swallowing the actual error
4. Timing issue with the policy-based approach

## Next Steps
1. Check the performHandshake implementation in detail
2. Add more logging to see where exactly it fails
3. Test with a minimal JavaScript file
4. Compare the exact DAP message sequence between working and broken versions
