What is the significance of the 'newListener' event in the Events module of Node.js?
- It is emitted when a new event listener is added.
- It is emitted when an event listener is removed.
- It is emitted when an error occurs in an event listener.
- It is emitted when an event is triggere
The 'newListener' event is emitted by the 'events' module whenever a new event listener is added to an event emitter. It is useful for tracking the addition of listeners and can be used for various purposes such as logging or monitoring.
How can you implement HTTP/2 using the http module in Node.js?
- HTTP/2 is automatically implemented when you use the http module in Node.js; no special configuration is required.
- You need to enable HTTP/2 by setting the http2 option to true when creating the http server instance.
- HTTP/2 is not supported in the http module of Node.js. You need to use a third-party library for HTTP/2 support.
- HTTP/2 can only be implemented using the https module, not the http module.
To implement HTTP/2 using the http module in Node.js, you need to enable HTTP/2 by setting the http2 option to true when creating the http server instance. This will allow you to take advantage of the features provided by HTTP/2 for improved performance and efficiency.
To allow CORS for all domains, the server should set the Access-Control-Allow-Origin header to ________.
- *
- localhost
- www.example.com
- Same-Origin
To allow CORS for all domains, the server should set the Access-Control-Allow-Origin header to *, which means any domain is allowed to access the resources. This should be done with caution as it can pose security risks if used improperly.
How can over-reliance on mocking and stubbing affect the reliability of a test suite?
- It can make tests overly complex
- It can lead to false positives
- It can obscure defects in the code
- It can slow down test execution
Over-reliance on mocking and stubbing can affect the reliability of a test suite by obscuring defects in the code. While mocks and stubs are valuable for isolating code under test, they may not catch integration-level issues. Options 1, 2, and 4 are also potential issues but are not directly related to reliability.
What is the key difference between dependencies and devDependencies in a Node.js project?
- Dependencies are used for production, while devDependencies are used for development only
- Dependencies are for frontend, while devDependencies are for backend
- Dependencies are automatically installed, while devDependencies require manual installation
- There is no difference; the terms are used interchangeably
The key difference is that "dependencies" are used in production, meaning they are essential for the application to run, while "devDependencies" are used only during development, for tasks like testing and building the project. This separation helps reduce the size of production deployments.
You are tasked with building a RESTful API using Express. How would you structure your application to handle different routes and HTTP methods efficiently and maintainably?
- Use Express Router for modular route handling, organize routes by resource, and utilize middleware for common functionality such as authentication and request validation.
- Define all routes in a single large file to simplify maintenance, use conditional statements for routing within the file, and avoid middleware for performance reasons.
- Create separate Express apps for each route, each running on a different port, and use proxy servers to route incoming requests to the appropriate app.
- Use a single route handler function for all routes and differentiate them based on the request method (GET, POST, etc.) within that function.
To build a maintainable and efficient Express application, it's recommended to use Express Router for modular route handling, organize routes logically, and employ middleware for common functionality. Option 2 may lead to code complexity, and options 3 and 4 are not recommended practices for building a RESTful API in Express.
In Express, the ______ method is used to specify a callback function to handle HTTP GET requests to a specified route.
- GET
- POST
- PUT
- callback
In Express.js, the GET method is used to specify a callback function to handle HTTP GET requests to a specified route. The GET method is a standard HTTP method for retrieving data from a server.
Which of the following is a commonly used caching mechanism in web development?
- Memcached
- Postgres
- SMTP
- HTTP
Memcached is a commonly used caching mechanism in web development. It is an in-memory key-value store that helps improve the speed and performance of web applications by caching frequently accessed data. The other options (Postgres, SMTP, and HTTP) are not caching mechanisms.
In which type of testing do you verify that different components of the system work together as expected?
- Integration Testing
- Unit Testing
- Functional Testing
- Stress Testing
Integration Testing verifies that different components of the system work together as expected. It checks the interactions between components and ensures they cooperate correctly.
What is the primary purpose of using an index in a database?
- To speed up data retrieval
- To enforce data constraints
- To store large binary data
- To define database structure
The primary purpose of using an index in a database is to speed up data retrieval. Indexes allow the database system to quickly locate and retrieve data, improving query performance.