agent-evals/IMPLEMENTATION_SUMMARY.md

Implementation Summary: File Listing Feature

Problem

The frontend was unable to list existing files because the backend API did not have an endpoint to retrieve the list of files in the data directory.

Root Cause

The backend API handler only supported individual file operations (GET /api/{filename}.md, POST /api/{filename}.md, etc.) but had no endpoint to list all files in the data directory. The frontend was attempting to fetch /api to get the file list, but this route was not configured.

Solution

Added a new endpoint GET /api that returns a JSON list of all markdown files in the data directory.

Changes Made

1. Backend API (backend/internal/api/api.go)

• Added handleListFiles() method that:
  • Reads all files from the data directory
  • Filters to only include .md files
  • Returns JSON response with format: {"files": ["file1.md", "file2.md", ...]}
• Modified handleGet() to check if filename is empty and call handleListFiles() if so

2. Backend Server (backend/internal/server/server.go)

• Added route handler for /api with GET method
• Kept existing route handler for /api/{filename:.+.md}

API Endpoints

New Endpoint

• Method: GET
• Path: /api
• Response: {"files": ["file1.md", "file2.md", ...]}
• Status Codes:
  • 200 OK - Success
  • 500 Internal Server Error - Failed to read directory

Existing Endpoints (Unchanged)

• GET /api/{filename}.md - Get file content
• POST /api/{filename}.md - Create file
• PUT /api/{filename}.md - Update file
• DELETE /api/{filename}.md - Delete file

Testing

Added comprehensive tests in backend/tests/file_listing_test.go:

• TestFileListing - Verifies multiple markdown files are listed
• TestFileListingWithNonMarkdownFiles - Verifies only .md files are returned
• TestFileListingEmptyDirectory - Verifies empty array for empty directory

All existing tests continue to pass.

Frontend Compatibility

The frontend (frontend/src/App.tsx) already expects the correct response format:

const loadFiles = async () => {
  const response = await fetch('/api')
  if (response.ok) {
    const data = await response.json()
    setFiles(data.files || [])  // Expects { files: string[] }
  }
}

No frontend changes were required.

Verification

The implementation was verified by:

1. Running all existing tests - ✅ PASS
2. Running new file listing tests - ✅ PASS
3. Manual API testing with curl - ✅ WORKING
4. Frontend build verification - ✅ SUCCESS

Files Modified

• backend/internal/api/api.go - Added file listing functionality
• backend/internal/server/server.go - Added /api route
• backend/tests/file_listing_test.go - Added comprehensive tests (NEW FILE)