Cannot log out from WebBrowser.openAuthSessionAsync in oauth flow for iOS13

🐛 Bug Report

Summary of Issue (just a few sentences)

When using WebBrowser.openAuthSessionAsync to implement Oauth flow (Google), Google sign-in state is remembered even after signing out from Google and uninstalling/reinstalling app.

Environment - output of expo diagnostics & the platform(s) you’re targeting

iOS 13 simulator

Steps to Reproduce

1. Configure app to use WebBrowser.openAuthSessionAsync to sign in and out via google oauth.
2. Sign in with Google account.
3. Confirm on Safari, you are also signed in on google.com
4. Sign out of app.
5. From Safari, go to google.com and sign out of Google.
6. (You can even uninstall / reinstall Expo app here)
7. Try signing into the app again.

Expected Behavior vs Actual Behavior

Expected that at this point, you should be prompted to sign into google again. However, the webview opened with WebBrowser.openAuthSessionAsync still somehow seems to have Google sign in cookies, and so it will just let you through.

This is ONLY happening on iOS 13. I have confirmed it does re-prompt on iOS 12 and below.

[brentvatne]

you can use the prompt param to always show the account picker: https://stackoverflow.com/a/14393492/659988

[github-actions[bot]]

This issue was closed because it has been inactive for 7 days since being marked as stale. Please open a new issue if you believe you are encountering a related problem.