NestJs Questions

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Score: 🔥 117

Beginner

Took 5 minutes

Programming Framework

NestJs

100%

Questions Attempted

10 / 10

Correct Answers

Incorrect Answers

Points Earned

🔥 10

Question 1

What is NOT a benefit of using Dependency Injection in NestJS?

Improved code testability.
Increased code coupling.
Enhanced code reusability.
Better maintainability of code.

Explanation:

Dependency Injection promotes loose coupling, not increased coupling. It allows components to depend on abstractions (interfaces) rather than concrete implementations.

Question 2

What is the purpose of the @Res() decorator in NestJS?

To define a new route
To access route parameters
To directly interact with the response object
To handle asynchronous operations

Explanation:

The @Res() decorator provides access to the underlying Express response object, allowing for manual manipulation of the response, such as setting headers or sending custom status codes.

Question 3

Which decorator is associated with removing resources in RESTful APIs?

@Get()
@Post()
@Put()
@Delete()

Explanation:

The @Delete() decorator signifies that a controller method handles HTTP DELETE requests, used for removing resources from the server.

Question 4

What is the role of the 'main.ts' file in a NestJS project?

Defines the application's database schema and models
Contains unit tests for the application's logic
Creates and configures the NestJS application instance
Stores environment variables and configuration settings

Explanation:

The main.ts file is the entry point of your NestJS application. It bootstraps the NestJS application, often setting up the listening port and other core configurations.

Question 5

What is the role of the app.module.ts file in a NestJS application?

It defines a single controller for handling HTTP requests.
It contains the application's main configuration and serves as the root module.
It defines a specific service for a particular business logic.
It handles routing logic for different API endpoints.

Explanation:

The app.module.ts file is the entry point of a NestJS application. It bootstraps the application and typically imports other modules, forming the application's dependency tree.

Question 6

Which interface does a custom exception filter in NestJS need to implement?

ExceptionFilter
HttpException
Injectable
CanActivate

Explanation:

The ExceptionFilter interface ensures that your custom filter class has the necessary catch() method for handling exceptions.

Question 7

What is the primary purpose of exception handling in a NestJS backend application?

To gracefully handle and respond to unexpected errors during request processing.
To enforce strict data typing in controller methods.
To handle database migrations and schema changes.
To define middleware functions for request-response cycles.

Explanation:

Exception handling is crucial for preventing application crashes and providing meaningful error responses to clients when unexpected situations arise during request handling.

Question 8

How does NestJS simplify unit testing of your application's components?

NestJS has built-in tools that automatically generate unit tests
NestJS applications do not require unit tests due to their strict architecture
NestJS's modular structure and dependency injection make it easy to isolate and test individual components
NestJS relies entirely on end-to-end testing, making unit tests unnecessary

Explanation:

The clear separation of concerns and the use of dependency injection in NestJS make it straightforward to mock dependencies and write focused unit tests for individual components.

Question 9

How do you access query parameters in a NestJS controller method?

Using @Body()
Using @Param()
Using @Query()
Using @Headers()

Explanation:

The @Query() decorator provides access to query parameters within a controller method. It allows you to retrieve values passed as key-value pairs in the URL's query string.

Question 10

How can you access the currently logged-in user within your middleware in NestJS?

By injecting the Request object into the middleware function.
By using the user property of the Response object.
By accessing the req.user object, assuming you have an authentication middleware set up.
By querying the database directly within the middleware.

Explanation:

If you're using an authentication middleware in NestJS, it typically attaches the authenticated user object to the request object. You can access this user information within your middleware by referring to req.user.