Social Login using Gmail in Nest JS

l Login using Gmail in Nest JS

In this article, we will learn how to implement the social login feature in Nest js.

1- Installation

First of all, install the dependencies using following commands

For NPM

npm i passport passport-facebook passport-google-oauth20

For Yarn

yarn add passport passport-facebook passport-google-oauth20

2- Configuration

In the src directory of your project, create a folder named “Services”. Create a googleStrategy.ts file in services folder.

import { PassportStrategy } from '@nestjs/passport';
import { Strategy, VerifyCallback } from 'passport-google-oauth20';
import { config } from 'dotenv';
import { Injectable } from '@nestjs/common';

config();

@Injectable()
export class GoogleStrategy extends PassportStrategy(Strategy, 'google') {

 constructor() {
   super({
       clientID: <your-clientID>,
       clientSecret: <your-clientSecret>,
       callbackURL: 'http://localhost:3000/google/redirect',
       scope: ['email', 'profile'],
     });
 }


 async validate (accessToken: string, refreshToken: string, profile: any, done: VerifyCallback): Promise<any> {
   const { name, emails, photos } = profile
   const user = {
     email: emails?.at(0).value,
     firstName: name?.givenName,
     lastName: name.familyName,
     picture: photos?.at(0).value,
     accessToken
   }
   done(null, user);
 }
}

2.1 — Go to console.google.com in your browser

2.2 — From side bar, go to API & Services -> Credentials

2.3 — Now, Click on create credentials and select OAuth Client ID

2.4 — After creating the client id and client secret, add it in your googleStrategy.ts file

3- Import googleStrategy in your module

import { GoogleStrategy } from './services/google.strategy';

@Module({
 ../
 providers: [GoogleStrategy],
})

export class AppModule { }

4- Setup your service file

src/app.service.ts

import { Injectable } from '@nestjs/common';

@Injectable()
export class AppService {

 googleLogin(req) {
   if (!req.user) {
     return 'No user from google'
   }

   return {
     message: 'User information from google',
     user: req.user
   }
 }
}

5- Setup your routes for social login using google

src/app.app.controller.ts

import { 
  Body, 
  Controller, 
  Get, 
  HttpStatus, 
  Post, 
  Req, 
  UseGuards
} from '@nestjs/common';
import { AppService } from './app.service';
import { AuthGuard } from '@nestjs/passport';

@Controller()
export class AppController {
 constructor(private readonly appService: AppService) {}

 @Get("auth/google")
 @UseGuards(AuthGuard('google'))
 async googleAuth(@Req() req) {}


 @Get('google/redirect')
 @UseGuards(AuthGuard('google'))
 googleAuthRedirect(@Req() req) {
   return this.appService.googleLogin(req)
 }
}

Now, you can login using google at following URL.

http://localhost:3000/auth/google

Congratulations, Now you have implemented social login using google in Nest JS.