How to active CORS in firebase functions with NestJs

0
votes

I'm running my backend in a firebase funcion with this code

// Nest Dependencies
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { ExpressAdapter } from '@nestjs/platform-express';
// Firebase Functions Dependencies
import * as functions from 'firebase-functions';
import * as express from 'express';
// Create a express server
const server = express();
const cors = require('cors');
// Create a NestServer With the Express server
const createNestServer = async (expressInstance: any): Promise<void> => {
  const app = await NestFactory.create(
    AppModule,
    new ExpressAdapter(expressInstance),
  );
  //Inititlize it
  await app.init();
};

// Create the google cloud function with the Nest Server(express server)
export const v1 = functions.https.onRequest(async (request, response) => {
  await createNestServer(server);
  server.use(cors({origin:true}))
  server(request, response);
});

But I'm getting This CORS error in my React frontend

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://dev-api.mytingo.com/v1/user/teacher/groups/active?idTeacher=179. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).

What I'm missing ? Thanks for your Help

2
node.jsgoogle-cloud-functionscorsnestjs

2 Answers

2
votes

You can try the following:

const createNestServer = async (expressInstance: any): Promise<void> => {
  const app = await NestFactory.create(
    AppModule,
    new ExpressAdapter(expressInstance),
  );
  //enable cors here
  app.enableCors();
  //Inititlize it
  await app.init();
};
1
votes

To quote Roman's answer:

If you follow this tutorial: https://fireship.io/snippets/setup-nestjs-on-cloud-functions/

You will then have the index.ts (in src folder) file that corresponds to the main.ts file of a NestJS application but for production. So you can activate the cors at this place as Roman advised you. Several options are possible, here is an example :

export const createNestServer = async (expressInstance) => {
  const app = await NestFactory.create(
    AppModule,
    new ExpressAdapter(expressInstance),
  );

  const corsOptions = {
    methods: 'GET',
    preflightContinue: true,
    optionsSuccessStatus: 204,
    credentials: true,
    origin: ['http://localhost:8100/'],
  };

  app.enableCors(corsOptions);

  return app.init();
};

Don't forget to build before restarting!

npm run build
firebase serve --only functions
firebase deploy --only functions