Fix/dupe state

[fant0mex]

Fixes #965
Fixes #1114

Description

Removes state and nonce from iOS additionalParameters after reading them, so they are not sent twice to AppAuth-iOS.

This matches the existing Android behavior and fixes Google errors like:

OAuth 2 parameters can only have a single value: state
OAuth 2 parameters can only have a single value: nonce

Verification

Manually verified in the iOS demo app using Google auth:

• additionalParameters.state completes without a duplicate state error.
• additionalParameters.nonce completes without a duplicate nonce error.

[changeset-bot]

🦋 Changeset detected

Latest commit: e838d7d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
react-native-app-auth	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[bryceknz]

Hey @fant0mex, long time no chat! I'm picking this PR up -- hope you don't mind. I'll make sure you get git credit 😊

I've rebased/merged it forward locally, kept your original state fix, and will add the matching nonce fix for #1114 since it has the same root cause.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
react-native-app-auth	Ready	Preview, Comment	May 18, 2026 2:00pm