In my web Firebase project, I am using signInWithPopup to sign in via Google. This works perfectly fine in production. When emulating Google authentication in development, though, the popup comes up, asks me for mock user details, I enter them but when I press submit, a cross-origin error occurs:
Uncaught DOMException: Blocked a frame with origin "http://localhost:9099" from accessing a cross-origin frame.
This error appears in the popup's console, NOT in my web app. I am not sure what could be causing this error. Here is the command that I am using to emulate auth:
firebase emulators:start --only "functions,firestore,auth"
Any help would be greatly appreciated.
EDIT: I believe this is a bug and have submitted a pull request to fix it.