nestjs-google-auth/src/auth/google-auth.module.ts

A reusable NestJS module for Google authentication using Passport.

import { DynamicModule, Module, Provider } from "@nestjs/common";
import { PassportModule } from "@nestjs/passport";
import { GoogleStrategy } from "./google.strategy";

@Module({})
export class GoogleAuthModule {
  static forRoot(options: {
    clientID: string;
    clientSecret: string;
    callbackURL: string;
    scope: string[];
    session?: boolean;
  }): DynamicModule {
    const googleStrategyProvider: Provider = {
      provide: GoogleStrategy,
      useFactory: () => {
        return new GoogleStrategy(options);
      },
    };

    return {
      module: GoogleAuthModule,
      providers: [GoogleStrategy, googleStrategyProvider],
      imports: [
        PassportModule.register({
          defaultStrategy: "google",
          session: options.session ?? false,
        }),
      ],
      exports: [GoogleStrategy],
    };
  }

  static forRootAsync(options: {
    useFactory: (...args: any[]) => Promise<any> | any;
    inject?: any[];
    session?: boolean;
  }): DynamicModule {
    const googleStrategyProvider: Provider = {
      provide: GoogleStrategy,
      useFactory: (options) => new GoogleStrategy(options),
      inject: options.inject || [],
    };

    return {
      module: GoogleAuthModule,
      providers: [GoogleStrategy, googleStrategyProvider],
      imports: [
        PassportModule.register({
          defaultStrategy: "google",
          session: options.session ?? false,
        }),
      ],
      exports: [GoogleStrategy],
    };
  }
}