Rate limiting with throttler in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the ThrottlerModule in a NestJS module.

NestJS

import { Module } from '@nestjs/common';
import { ThrottlerModule } from '@nestjs/throttler';

@Module({
  imports: [ThrottlerModule.[1]({ ttl: 60, limit: 10 })],
})
export class AppModule {}

Drag options to blanks, or click blank then click option'

AforRoot

Bcreate

Cregister

DforRootAsync

Attempts:

3 left

💡 Hint

Common Mistakes

Using forRootAsync without async configuration.

Using register which is not a method of ThrottlerModule.

Using create which does not exist.

The ThrottlerModule is imported using the forRoot() method to set global rate limiting options.

2fill in blank

medium

Complete the code to apply the ThrottlerGuard globally in the module using providers.

NestJS

import { Module } from '@nestjs/common';
import { ThrottlerGuard } from '@nestjs/throttler';
import { [1] } from '@nestjs/core';

@Module({
  providers: [
    {
      provide: [1],
      useClass: ThrottlerGuard
    }
  ],
})
export class AppModule {}

Drag options to blanks, or click blank then click option'

AAPP_GUARD

BGuard

CCanActivate

DInjectable

Attempts:

3 left

💡 Hint

Common Mistakes

Importing CanActivate which is an interface, not a token.

Importing Guard which does not exist.

Importing Injectable which is a decorator.

APP_GUARD is imported from '@nestjs/core' to provide global guard tokens. It is used as the provide token to register ThrottlerGuard as a global guard.

3fill in blank

hard

Fix the error in the controller method to apply rate limiting with @Throttle decorator.

NestJS

import { Controller, Get } from '@nestjs/common';
import { Throttle } from '@nestjs/throttler';

@Controller('cats')
export class CatsController {
  @Get()
  @Throttle([1])
  findAll() {
    return 'This action returns all cats';
  }
}

Drag options to blanks, or click blank then click option'

A10, ttl: 60

B10, 60

C60, 10

D{ limit: 10, ttl: 60 }

Attempts:

3 left

💡 Hint

Common Mistakes

Passing an object instead of two numbers.

Using named parameters inside the decorator.

Passing a single number.

The @Throttle decorator takes two positional arguments: limit and ttl (time to live in seconds). So @Throttle(10, 60) means max 10 requests per 60 seconds.

4fill in blank

hard

Fill both blanks to configure ThrottlerModule with a 30-second window and 5 requests limit.

NestJS

import { Module } from '@nestjs/common';
import { ThrottlerModule } from '@nestjs/throttler';

@Module({
  imports: [ThrottlerModule.forRoot({ ttl: [1], limit: [2] })],
})
export class AppModule {}

Drag options to blanks, or click blank then click option'

A30

B5

C60

D10

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping ttl and limit values.

Using default values instead of specified ones.

The ttl is the time window in seconds (30), and limit is the max requests allowed (5).

5fill in blank

hard

Fill all three blanks to create a custom ThrottlerGuard that ignores requests from admin users.

NestJS

import { Injectable, ExecutionContext } from '@nestjs/common';
import { ThrottlerGuard } from '@nestjs/throttler';

@Injectable()
export class [1] extends ThrottlerGuard {
  protected getTracker(req: any): string {
    const user = req.user;
    if (user && user.role === [2]) {
      return [3];
    }
    return super.getTracker(req);
  }
}

Drag options to blanks, or click blank then click option'

ACustomThrottlerGuard

B'admin'

C'skip'

DAdminGuard

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect class names.

Using role without quotes.

Returning wrong string to skip rate limiting.

The class is named CustomThrottlerGuard, the role to check is 'admin', and returning 'skip' tells the guard to ignore rate limiting for that user.