Error: INTERNAL ASSERTION FAILED: Pending promise was never set

[tanuj101]

[REQUIRED] Describe your environment

• Operating System version: Ubuntu 22.04.1 LTS
• Browser version: Firefox 110.0.1
• Firebase SDK version: 9.14.0
• Firebase Product: auth

[REQUIRED] Describe the problem

When using signInWithPopup to sign in with Microsoft, An unhandled error is thrown INTERNAL ASSERTION FAILED: Pending promise was never set. This issue happens 5/10 times which makes it difficult to offer authentication with Microsoft.
P.S. This flow works perfectly fine on google chrome.

Steps to reproduce:

• Setup sign-in button.
• Execute signInWithPopup function from firebase/auth.

Relevant Code:

    const provider = new OAuthProvider('microsoft.com');
    const auth = getAuth();
    const credentials = await signInWithPopup(auth, provider);

[jbalidiong]

Hi @tanuj101, thanks for reaching out. I tried replicating, but I wasn't able to reproduce the error.

If I can replicate the issue, I can have a better look into it. Please share a minimal, but complete sample of a project that I can run locally.

[tanuj101]

Hi @jbalidiong, Thanks for responding. I've created a minimal code project where the issue is still reproducible on firefox https://codepen.io/Tanuj69/pen/wvErMrm, Once you add application configuration in initializeApp. The page will load.
Also adding a screenshot for your reference with the trace of the error which occurs in the original application -

[jbalidiong]

Thanks for the additional information @tanuj101. I was able to replicate the issue when running it on Firefox. Let me check what we can do for this issue or bring someone from our Auth team here that can provide more context about it. I’ll update this thread if I have any information to share.

[silas]

This might be the same issue as #6956. It seems like there is Firefox specific handling in /__/auth/handler (or maybe the auth library) which is causing problems.

You can probably confirm this by installing something like https://addons.mozilla.org/en-US/firefox/addon/uaswitcher/ and faking a chrome user-agent. If you don't see the failure anymore, probably the same issue.

[tanuj101]

It seems due to this issue, the same bug also exists in firebaseui-web library since April 6, 2022.

[bhparijat]

Hi Tanuj,
Thank you for bringing this up. While we work on figuring out the cause here, could you please try @silas's hack. It may help us understand this better. b/272821123 for google internal tracking. Thanks!!

[tanuj101]

@bhparijat Thanks, but faking a user-agent that @silas mentioned is not a hack but a proof that there is some firefox specific code that is causing this issue. We can not ask our users to use this extension :)

[silas]

@tanuj101 I think @bhparijat is just asking you to confirm/deny that setting the user-agent fixes the issue, not to actually recommend it as a workaround to your users.