You are working on a project that has several outdated packages with known vulnerabilities. What approach would you take to update those packages while ensuring the stability of the project?
- Update all packages to their latest versions immediately
- Review the changelogs of outdated packages, perform incremental updates, and thoroughly test each update
- Ignore the outdated packages as they may not impact the project
- Downgrade the Node.js version to maintain package compatibility
The correct approach is to review the changelogs of outdated packages, perform incremental updates, and thoroughly test each update. This ensures that updates do not introduce breaking changes and maintain project stability.
Which of the following is the correct way to parse JSON in the body of a request in Express.js?
- app.use(express.json())
- app.use(body.parse())
- app.use(request.json())
- app.parse(json)
To parse JSON in the body of a request in Express.js, you should use app.use(express.json()). This middleware is used to parse JSON data in the request body. The other options do not represent the correct way to parse JSON in Express.js.
Which of the following is the correct way to declare a variable in JavaScript?
- var x = 10;
- x := 10;
- int x = 10;
- declare x = 10;
In JavaScript, variables can be declared using the var keyword. The other options are either used in different programming languages or are not valid syntax in JavaScript.
In JavaScript, a for…in loop is used to iterate over the ________ of an object.
- properties
- values
- methods
- variables
In JavaScript, a for...in loop is used to iterate over the properties of an object. It is commonly used for object iteration, and it iterates through the keys or property names of an object.
In Sequelize, which method is commonly used to find a single instance from the database?
- findAll()
- findOne()
- findSingle()
- fetchOne()
In Sequelize, the commonly used method to find a single instance from the database is findOne(). This method retrieves the first matching record that meets the specified criteria. The other options, findAll(), findSingle(), and fetchOne(), do not represent the standard method for retrieving a single instance in Sequelize.
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.
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.
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.
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.
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.
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.
Which of the following responses to a preflight request will allow a browser to make a cross-origin call to upload a file?
- Access-Control-Allow-Origin: *
- Access-Control-Allow-Methods: POST
- Access-Control-Allow-Headers: Authorization
- Access-Control-Allow-Credentials: true
To enable cross-origin file uploads, you need to set Access-Control-Allow-Credentials to true, indicating that credentials like cookies are allowed. The other options are necessary but don't specifically address file uploads.