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.
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.
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.
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.
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.
To handle HTTPS requests using the http module, the ______ module should also be used in conjunction.
- net
- tls
- crypto
- url
To handle HTTPS requests using the http module, the tls (Transport Layer Security) module should also be used in conjunction. TLS provides encryption and security for HTTPS connections. The net module is used for basic networking, crypto for cryptographic operations, and url for parsing URL strings, but tls is specifically used for securing HTTP with HTTPS.
How do database management systems typically handle indexing of JSON and XML data types?
- They don't support indexing for JSON and XML data types.
- They create traditional B-tree indexes for JSON and XML data.
- They use specialized indexing techniques like GIN (Generalized Inverted Index) and GIST (Generalized Search Tree) for JSON and XML data.
- They rely on external search engines for indexing JSON and XML data.
Database management systems typically use specialized indexing techniques like GIN (Generalized Inverted Index) and GIST (Generalized Search Tree) for JSON and XML data types. These indexes are designed to efficiently handle the hierarchical and semi-structured nature of JSON and XML data.
What is the primary benefit of implementing a Write-Through caching strategy?
- Improved cache hit rates
- Reduced latency for write operations
- Reduced storage space requirements
- Simplified cache management
The primary benefit of a Write-Through caching strategy is reduced latency for write operations. Data is written to both the cache and the underlying data store simultaneously, ensuring that the cache and data store are always in sync.
You are tasked with refactoring a large codebase to make it more modular. What considerations should you have regarding the import and export of modules to ensure smooth transition and maintainability?
- Use default exports for all modules.
- Avoid circular dependencies between modules.
- Use global variables for module access.
- Mix HTML and JavaScript in modules for simplicity.
When refactoring a codebase to make it more modular, you should avoid circular dependencies between modules (Option b). Circular dependencies can lead to maintenance challenges and make the codebase harder to understand. Using default exports for all modules (Option a) is not a best practice as it can limit the flexibility of importing modules. Using global variables (Option c) and mixing HTML and JavaScript (Option d) go against the principles of modularity and should be avoided.
How is Passport.js beneficial for implementing various authentication strategies in Express.js applications?
- Passport.js is not related to authentication in Express.js.
- Passport.js provides a single authentication strategy that is suitable for all use cases.
- Passport.js is a middleware for implementing multiple authentication strategies in Express.js applications.
- Passport.js is primarily used for session management, not authentication.
Passport.js is a popular middleware for Express.js that allows you to implement multiple authentication strategies, including OAuth, local (username and password), and many others. It simplifies the process of integrating different authentication methods into your Express.js application.
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.
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.