When using stubs, the main focus is on ______ rather than on verifying interactions between objects.
- State
- Behavior
- Structure
- Performance
When using stubs in testing, the main focus is on the state of the object, such as returning predefined values, rather than on verifying interactions between objects. Stubs are used to control the behavior of the object under test without asserting specific interactions.
The OpenID Connect protocol is an extension of ______ and is used for authentication as well as identity provisioning in web applications.
- OAuth 2.0
- SAML
- JWT
- LDAP
The OpenID Connect (OIDC) protocol is indeed an extension of OAuth 2.0. It is designed to provide identity and authentication services on top of OAuth 2.0, making it a powerful tool for web application security. SAML, JWT, and LDAP are different technologies with distinct purposes.
Which of the following is a correct way to declare a function in JavaScript?
- function myFunction() => { ... }
- func myFunction() { ... }
- def myFunction() { ... }
- myFunction => { ... }
In JavaScript, functions are declared using the function keyword, followed by the function name and parentheses. The correct syntax is function myFunction() { ... }. The other options are not valid ways to declare functions in JavaScript.
What is the main purpose of using 'describe' and 'it' blocks in Mocha?
- Defining Test Suites and Test Cases
- Creating HTML Elements
- Importing External Libraries
- Generating Random Numbers
In Mocha, 'describe' blocks are used for defining test suites or groups of related test cases, and 'it' blocks are used for specifying individual test cases. This helps in organizing and structuring your test suite, making it more readable and maintainable.
In JavaScript, closures are crucial for functional programming as they facilitate the creation of ________.
- Private Variables
- Callbacks
- Promises
- Modules
Closures in JavaScript allow the creation of private variables within functions. This encapsulation is essential for functional programming, where data should be isolated and not directly accessible from outside the function.
You are developing a high-traffic e-commerce website. You need to implement a caching strategy to ensure that the load on the database is minimized, and the data retrieval is fast. Which caching strategy would be most suitable, and why?
- In-Memory Caching
- File-Based Caching
- Database Indexing
- No Caching
In this high-traffic scenario, In-Memory Caching would be the most suitable caching strategy. It stores frequently accessed data in RAM, ensuring rapid data retrieval and minimizing the load on the database server. File-Based Caching and Database Indexing may not offer the same level of performance improvement, and not using caching (No Caching) would increase the load on the database.
Why is input validation crucial in web development?
- To ensure data is entered correctly.
- To make web forms look more attractive.
- To increase website loading speed.
- To prevent SQL injection.
Input validation is crucial in web development to prevent security vulnerabilities like SQL injection and to ensure that the data entered by users is correct and safe. It helps protect against malicious input and maintain data integrity.
You are tasked with improving the reliability of a large codebase. Using Jest, how would you approach writing tests for functions with side effects like database calls or API requests?
- Use Jest's mocking capabilities to create mocks or spies for database and API calls.
- Skip testing functions with side effects; focus on pure functions.
- Manually perform database/API calls in tests to ensure real-world reliability.
- Use only integration tests for functions with side effects.
To improve reliability and isolate side effects, you should use Jest's mocking capabilities to create mocks or spies for database and API calls. This way, you can control and verify the behavior of these calls without involving the actual database or API. The other options may lead to unreliable tests or skipped testing.
When a package is listed under devDependencies, it means that the package is only required during the ________ of the application.
- development
- deployment
- testing
- runtime
When a package is listed under devDependencies, it means that the package is only required during the development of the application. These are typically tools and libraries used for development, such as testing frameworks, build tools, and linters. They aren't needed in the production or deployment environment.
You are tasked with developing a function to flatten a nested array structure. Which method would you use to flatten the arrays efficiently?
- Recursive function
- Array.prototype.flatMap()
- Nested loops
- Array.prototype.concat()
To efficiently flatten a nested array structure, you can use Array.prototype.flatMap(). It not only flattens the array but also allows you to transform its elements if needed. Using recursion is an option but can lead to stack overflow errors for deeply nested arrays.