# Chrome Extension Error Fixes Summary

## Fixed Errors:
1. **"The message port closed before a response was received"**
2. **"Cannot read properties of undefined (reading 'trim')"**

## Changes Made:

### 1. Message Port Error Fixes (content.js)
- Added `return true` for async operations in message listener
- Implemented `handleDataExtraction()` async method with timeout protection
- Added HTML compression for large payloads (>50MB)
- Implemented retry logic with exponential backoff

### 2. Undefined Trim() Error Fixes (content.js)
All regex match results now check for existence before calling `.trim()`:

- **Line 442**: `if (match && match[1])`
- **Line 529**: `if (match && match[1])`  
- **Line 573**: `if (match && match[1])`
- **Line 659**: `if (match && match[1] && match[1].trim())`
- **Line 705**: `if (match && match[1])`
- **Line 729**: `if (cityMatch && cityMatch[1])`
- **Line 751**: `if (cityMatch && cityMatch[1])`
- **Line 772**: `if (flexibleMatch && flexibleMatch[1])`
- **Line 806**: `if (match && match[1])`

### 3. Document Body Safety Checks
Added fallbacks for potentially undefined document properties:

- **Line 190**: `const bodyText = (document.body.textContent || '').trim()`
- **Line 259**: `const pageText = (document.body.textContent || document.body.innerText || '')`
- **Line 413**: `const pageText = document.body.textContent || document.body.innerText || ''`
- **Line 599**: `const pageText = document.body.textContent || document.body.innerText || ''`
- **Line 789**: `const pageText = document.body.textContent || document.body.innerText || ''`

### 4. Enhanced Error Handling (popup.js)
- Implemented `extractDataWithRetry()` with 3 retry attempts
- Added 45-second timeout per attempt
- Content script reinjection on failure
- Background script forwarding as fallback

### 5. Background Script Improvements (background.js)
- Added message forwarding capabilities
- Implemented storage-based fallback
- Better error handling with specific error messages
- Health check endpoint for debugging

### 6. Manifest Permissions (manifest.json)
- Added `scripting` permission for content script reinjection

## Testing Instructions:

1. **Reload the extension:**
   - Go to `chrome://extensions/`
   - Find "DCS Credit Application Processor"
   - Click the refresh icon

2. **Test on a DCS page:**
   - Navigate to a DCS credit application page
   - Open the extension popup
   - Click "Process DCS Application"
   - Check browser console for any errors

3. **Monitor console logs:**
   - Open Developer Tools (F12)
   - Check for extraction success messages
   - Look for any remaining trim() errors

## Expected Results:
- No "message port closed" errors
- No "Cannot read properties of undefined" errors
- Successful data extraction with field count displayed
- Automatic retry on temporary failures
- Graceful handling of large HTML content

## Debug Commands:
Run these in the browser console to test specific fixes:

```javascript
// Test message handling
chrome.runtime.sendMessage({action: 'healthCheck'}, response => console.log('Health:', response));

// Test extraction (run on DCS page)
chrome.runtime.sendMessage({action: 'extractData'}, response => console.log('Extract:', response));
```