Summary
I am trying to test out the authorization with cloud functions by serving a local web app and calling them (as emulators can't emulate auth? See: Docs). My issue is that when I click the button on the served page that calls the cloud function, it tries to access the cloud function at: https://us-central1-MY-PROJECT.cloudfunctions.net/returnAuth resulting in a Cors issue. How do I get my web app to call the local cloud functions for testing? My suspicion is it is something inside of the firebaseConfig inside of the index.html?
I realize I will probably need to enable Cors, as the port the cloud functions are served on is different. But that is a different question from what I am asking.
Serving
I am serving my cloud functions as well as the index.html via the cmd firebase serve
which results in:
i  functions: Watching "/Users/plum/firebase-test/test1/functions" for Cloud Functions...
i  hosting: Serving hosting files from: public
✔  hosting: Local server: http://localhost:5000
✔  functions[returnAuth]: http function initialized (http://localhost:5001/MY_PROJECT/us-central1/returnAuth).
Error
Access to fetch at 'https://us-central1-MY-PROJECT.cloudfunctions.net/returnAuth' from origin 'http://localhost:5000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
Failed to load resource: net::ERR_FAILED
Code: internal   Message: internal   Details: undefined
Simple Cloud Function
const functions = require('firebase-functions');
const admin = require('firebase-admin');
const { exampleDataSnapshotChange } = require('firebase-functions-test/lib/providers/database');
admin.initializeApp();
exports.returnAuth = functions.https.onCall( (data, context) => {
    //const uid = context.auth.uid;
    //const name = context.auth.token.name || null;
    const test = context.auth
    return test
})
Simple Index.html
 <!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <script
  src="https://code.jquery.com/jquery-3.5.1.min.js"
  integrity="sha256-9/aliU8dGd2tb6OSsuzixeV4y/faTqgFtohetphbbj0="
  crossorigin="anonymous"></script>
  </head>
  <body>
    <div id="app">
        <button id="Test1">Test 1</button>
    </div>
    <script>
        $(document).ready(function() {
            $("#Test1").on('click', function() {
                var testAuth = firebase.functions().httpsCallable('returnAuth');
                testAuth({text: "Testing"}).then(function(result) {
                    var sanitizedMessage = result.data.text;
                    console.log(sanitizedMessage);
                })
                .catch(function(error) {
                var code = error.code;
                var message = error.message;
                var details = error.details;
                console.log(`Code: ${code}\t Message: ${message}\t Details: ${details}`)
                })
            })
            
        })
    </script>
        <!-- The core Firebase JS SDK is always required and must be listed first -->
    <script src="https://www.gstatic.com/firebasejs/7.19.0/firebase-app.js"></script>
    <!-- TODO: Add SDKs for Firebase products that you want to use
        https://firebase.google.com/docs/web/setup#available-libraries -->
    <script src="https://www.gstatic.com/firebasejs/7.19.0/firebase-analytics.js"></script>
    <script src="https://www.gstatic.com/firebasejs/7.19.0/firebase-functions.js"></script>
    <script src="/__/firebase/7.19.0/firebase-auth.js"></script>
    <script>
    // Your web app's Firebase configuration
    var firebaseConfig = {
        apiKey: "HIDDEN",
        authDomain: "MY-PROJECT.firebaseapp.com",
        databaseURL: "https://MY-PROJECT.firebaseio.com",
        projectId: "MY-PROJECT",
        storageBucket: "MY-PROJECT.appspot.com",
        messagingSenderId: "SOME_NUMBER",
        appId: "1:HASH:web:OTHER_HASH",
        measurementId: "G-HASH"
    };
    // Initialize Firebase
    firebase.initializeApp(firebaseConfig);
    firebase.analytics();
    </script>
  </body>
</html>
