JWT strategy in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the JWT strategy class from Passport.

NestJS

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

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AJwtService

BJwtModule

CJwtStrategy

DPassportStrategy

Attempts:

3 left

💡 Hint

Common Mistakes

Importing JwtStrategy directly from @nestjs/passport (it is usually a custom class).

Confusing JwtModule with PassportStrategy.

The JWT strategy class extends PassportStrategy, so you import PassportStrategy from @nestjs/passport.

2fill in blank

medium

Complete the code to extract the JWT token from the request header.

NestJS

super({ jwtFromRequest: ExtractJwt.[1](), secretOrKey: secret });

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AfromBodyField

BfromAuthHeaderAsBearerToken

CfromUrlQueryParameter

DfromCookie

Attempts:

3 left

💡 Hint

Common Mistakes

Using fromBodyField which expects token in the request body.

Using fromUrlQueryParameter which expects token in URL.

The JWT token is usually sent in the Authorization header as a Bearer token, so use fromAuthHeaderAsBearerToken().

3fill in blank

hard

Fix the error in the validate method to correctly return the user payload.

NestJS

async validate(payload: any) {
  return [1];
}

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Apayload.user

Bpayload.sub

Cpayload

Dpayload.id

Attempts:

3 left

💡 Hint

Common Mistakes

Returning only payload.sub which is just the user id.

Returning payload.user which may not exist.

The validate method should return the entire payload object which represents the user info extracted from the token.

4fill in blank

hard

Fill both blanks to correctly define the JWT strategy class extending PassportStrategy.

NestJS

export class JwtStrategy extends [1](Strategy) {
  constructor() {
    super({
      jwtFromRequest: ExtractJwt.[2](),
      secretOrKey: process.env.JWT_SECRET,
    });
  }
}

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APassportStrategy

BJwtStrategy

CfromAuthHeaderAsBearerToken

DfromBodyField

Attempts:

3 left

💡 Hint

Common Mistakes

Using JwtStrategy as base class instead of PassportStrategy.

Using fromBodyField instead of fromAuthHeaderAsBearerToken.

The class extends PassportStrategy with the JWT Strategy. The token is extracted using fromAuthHeaderAsBearerToken().

5fill in blank

hard

Fill all three blanks to create a validate method that returns user info from the payload.

NestJS

async validate(payload: any) {
  const user = {
    id: payload.[1],
    username: payload.[2],
    email: payload.[3]
  };
  return user;
}

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Asub

Busername

Cemail

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'id' instead of 'sub' for user id.

Mixing up username and email fields.

The JWT payload usually has sub for user id, and username and email fields for user info.