Express Server Agent
1. Build & Development Commands: Project Setup:
Use npm install to install all dependencies specified in package.json.
Ensure the .env file is present in the project root with the GOOGLE_API_KEY environment variable set.
Running the Server:
Use node index.js or npm start to run the server.
Use nodemon index.js for development to enable automatic server restarts on file changes.
Dependency Management:
Add new dependencies using npm install <package-name> --save.
Remove dependencies using npm uninstall <package-name> --save.
Never alter package-lock.json manually.
Environment Variables:
All sensitive information, especially the Google Gemini API key, must be stored in the .env file.
Access environment variables using process.env.<VARIABLE_NAME>.
2. Testing Guidelines:

Unit Testing:
Implement unit tests for all core functions (e.g., generateResponse, startChat).
Use a testing framework like Jest or Mocha with Chai or Supertest.
Integration Testing:
Write integration tests to verify the behavior of API endpoints.
Test API endpoints with various input scenarios, including edge cases and error conditions.
API Testing:
Use Postman or curl to manually test API endpoints during development.
Verify that API responses are in the expected format and contain the correct data.
Error Handling:
Test error handling scenarios to ensure the server responds appropriately to invalid requests or API errors.
3. Code Style & Guidelines:

JavaScript Style:
Follow a consistent coding style (e.g., Airbnb JavaScript Style Guide).
Use ESLint to enforce code style and catch potential errors.
Use Prettier for automatic code formatting.
Code Organization:
Structure the codebase logically with separate files or modules for different functionalities.
Use comments to explain complex logic or non-obvious code sections.
Utilize Async/Await for asynchronous code.
Error Handling:
Implement robust error handling using try...catch blocks.
Log errors using Winston or a similar logging library.
Return meaningful error messages to the client.
Dependencies:
Use the dependencies listed in your package.json, and keep them updated.
Use Morgan for HTTP request logging.
Use lru-cache to cache frequent API requests.
Use Multer to handle multipart/form-data.
Use Body-parser to parse request bodies.
Use Node-fetch to make http requests.
Security:
Sanitize user inputs to prevent security vulnerabilities.
Implement proper authentication and authorization if necessary.
Use Cors to control which origins can access the API.
Documentation:
Document all API endpoints with clear descriptions of request parameters and response formats.
Document the server's setup and configuration.