Calling cypress-firebase's cy.login() does not result in logged-in user

Question

I am using Cypress for end-to-end testing an application, together with the cypress-firebase package. I followed the official setup instructions (using TypeScript, and the Firebase Web SDK version 9 with the compat mode).

In my tests, calling cy.login() seems to work as expected in that Cypress logs that the createCustomToken task successfully performs two HTTP POSTs with status code 200 each.

However, when visiting a page of the application afterwards, no user is logged in. In the application, the login status is supposed to be detected using Firebase's onAuthStateChanged function. It seems that cy.login() never triggers onAuthStateChanged, though.

My best guess is that maybe the auth instances used by cypress-firebase and the application code are not the same?! Is there a way to confirm this, or could there be another reason?

Happy to provide further information if it may help.

Answer 1

The issue was indeed related to auth instances not matching: The application was using a named instance, whereas the initializeApp code in Cypress was not naming the app (and thus relying in an app instance named [DEFAULT]).

Fortunately, cypress-firebase has support for named apps:

const namedApp = firebase.initializeApp(fbConfig, "app_name");

attachCustomCommands({ Cypress, cy, firebase, app: namedApp });