CODEWITHSUNDEEP
javascriptfirebasegoogle-cloud-functions
skwny
skwny

Reputation: 3140

Firebase HTTP function CORS issue

I cannot get my Firebase http function working when calling it from the client. Here are the errors on the client:

OPTIONS https://us-central1-my-app.cloudfunctions.net/my-func 500 ()

Failed to load https://us-central1-my-app.cloudfunctions.net/my-func: 
Response to preflight request doesn't pass access control check:
No 'Access-Control-Allow-Origin' header is present on the requested resource. 
Origin 'http://localhost:3000' is therefore not allowed access. 
The response had HTTP status code 500.

Here is what my function looks like:

const admin = require('firebase-admin');
const functions = require('firebase-functions');
const cors = require('cors')({origin: true});

exports.func = functions.https.onRequest((req, res) => {
  return cors((req, res, () => {
    res.send("hello");
  }));
});

The Firebase functions log is providing this information:

TypeError: Cannot read property 'origin' of undefined
    at /user_code/node_modules/cors/lib/index.js:219:39
    at optionsCallback (/user_code/node_modules/cors/lib/index.js:199:9)
    at corsMiddleware (/user_code/node_modules/cors/lib/index.js:204:7)
    at exports.pay.functions.https.onRequest (/user_code/my-func.js:11:10)

Note that 11:10 in the call stack is this: return cors((req, res, () => {

The request I'm making is sending an object with a single key:value pair in the request body. I added the cors middleware based on other questions I've seen on SO, but no luck!

Edit: Adding the request code:

function post(url, obj) {
  return new Promise((resolve, reject) => {
    const req = new XMLHttpRequest();
    req.open('POST', url, true);
    req.setRequestHeader("Content-type", "application/json");

    req.onload = function() {
      if(req.status == 200) {
        return resolve(req.response);
      }
      else {
        return reject(Error(req.statusText));
      }
    };

    req.onerror = function() {
      return reject(Error("Network Error"));
    };

    req.send(JSON.stringify(obj));
  });
}

Upvotes: 2

Views: 2594

Answers (1)

skwny
skwny

Reputation: 3140

Programmer error, as usual:

cors((req, res, () => {
    res.send("hello");
  }));

should be:

cors(req, res, () => {
    res.send("hello");
  });

Had an extra set of parens around the cors args.

Upvotes: 9

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