The appState parameter is missing for login with redirect on the web

[navaronbracke]

Checklist

• The issue can be reproduced in the auth0_flutter sample app (or N/A).
• I have looked into the Readme, Examples, and FAQ and have not found a suitable solution or answer.
• I have looked into the API documentation and have not found a suitable solution or answer.
• I have searched the issues and have not found a suitable solution or answer.
• I have searched the Auth0 Community forums and have not found a suitable solution or answer.
• I agree to the terms within the Auth0 Code of Conduct.

Description

When implementing a login with redirect flow for Flutter Web, I initially got it working as expected, without adding any extra state for redirects. However, when I needed to implement a redirect after login, I had to look around on how to do that.

I had been referred to the following documentation, by a colleague of mine:
https://auth0.com/docs/secure/attack-protection/state-parameters

So I started implementing the workflow as described in that document.
However, the document mentions a state query parameter, without disclosing that Auth0 itself uses a state query parameter in the redirect URL, for validation purposes in the Auth0 SDK.

After some searching, I did find out that there is an appState parameter for the redirect login options.
See the answer at https://community.auth0.com/t/how-to-preserve-client-state-after-loginwithredirect/95963/6

Then I did some digging and found that this parameter is defined in the SDK as stated in the comment above
https://github.com/auth0/auth0-spa-js/blob/f2e566849efa398ca599daf9ebdfbbd62fcb1894/src/global.ts#L298

However, the Flutter plugin lacks this field in its implementation.

Reproduction

1. flutter create auth0_sample --platforms=web
2. flutter pub add auth0_flutter
3. Implement the standard login functionality, for example with http://localhost:3000 as callback url's for login / logout
4. Try adding the appState to the arguments of loginWithRedirect(), so that this state is returned back in the redirect url query parameters (albeit encoded)
5. Observe that there is no way to add the app state. Putting the app state in the parameters map does not work either

Additional context

No response

auth0_flutter version

1.7.2

Flutter version

3.24.3

Platform

Web

Platform version(s)

Google Chrome 131.0.6778.70