Firebase HTTP function CORS

Question

I\'m still having problems with CORS when using Firebase HTTP functions.

Here is my web console error:

Response to preflight request doesn\'t pass ac         


        

Answer 1

According to the Firebase documentation, there are a couple of references to CORS configuration:

Using CORS:

You can enable the use of CORS by calling it within the function, just like you did in your update to the question:

// Usage of the `cors` express middleware
return cors(req, res, () => {
  // TO-DO
});

Also if you have an already existing Express app, you can then enable CORS by doing:

const app = express();
app.use(cors({ origin: true }));

This is what you had already done on the first step, but there's the difference in the { origin: true } definition, so maybe that is related.

In any case, as per the documentation it looks like it is indeed fine to add the cors within the request.