Role-based authorization in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the decorator used to define roles in NestJS.

NestJS

import { [1] } from '@nestjs/common';

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ASetMetadata

BRoles

CUseGuards

DController

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Roles' decorator which is not built-in

Importing 'UseGuards' instead of 'SetMetadata'

The SetMetadata decorator is used to define custom metadata like roles in NestJS.

2fill in blank

medium

Complete the code to create a custom decorator named Roles that sets roles metadata.

NestJS

export const Roles = (...roles: string[]) => [1]('roles', roles);

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ASetMetadata

BUseGuards

CController

DInjectable

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'UseGuards' instead of 'SetMetadata'

Trying to use 'Controller' decorator here

The SetMetadata function attaches the roles array as metadata to the route handler.

3fill in blank

hard

Fix the error in the guard to get roles metadata using the correct method.

NestJS

const roles = this.reflector.[1]('roles', context.getHandler());

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AgetAll

Bfind

Cfetch

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'fetch' or 'find' which do not exist on Reflector

Using 'getAll' which is not a method here

The Reflector class uses the get method to retrieve metadata by key.

4fill in blank

hard

Fill both blanks to check if the user has any of the required roles in the guard.

NestJS

return roles.some(role => user.roles.[1](role)) && user.isActive === [2];

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Aincludes

BindexOf

ChasOwnProperty

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'indexOf' without checking for -1

Checking user.isActive against 'false'

The includes method checks if the user's roles contain the required role. The user must be active, so true is checked.

5fill in blank

hard

Fill both blanks to apply the Roles decorator and guard to a controller route.

NestJS

@[1]('admin')
@UseGuards([2])
@Get('admin')
adminRoute() {
  return 'Admin content';
}

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ARoles

BRolesGuard

CAuthGuard

DController

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'Controller' decorator on a method

Using 'AuthGuard' instead of 'RolesGuard'

The Roles decorator sets roles metadata, RolesGuard enforces role checks.