Yahoo OAuth fails with invalid scope error

[AbishekHari]

Step 1: Are you in the right place?

Step 2: Describe your environment

• Objective C or Swift: Swift
• iOS version: iOS 13
• Firebase SDK version: 10.6.0
• FirebaseUI version: 12.2.0
• CocoaPods Version: 1.11.1

Step 3: Describe the problem:

OAuth with the yahoo provider verification step fails with an invalid scope error.

I confirmed that the application registration with Yahoo is correct as I was able to successfully authenticate using the FirebaseUI-Android library.

As per yahoo documentation, to get an ID Token to authenticate a user, you are required to specify the scope identifier openid. For example: scope=openid
Reference: https://developer.yahoo.com/oauth2/guide/openid_connect/getting_started.html

Steps to reproduce:

1. Register an application with yahoo - https://developer.yahoo.com/oauth2/guide/openid_connect/getting_started.html
2. Enable Yahoo sign-in, configure the auth provider
3. Attempt to initiate authentication using yahoo provider

Observed Results:

• Yahoo OAuth request fails with error

Error getting verification code from yahoo.com response: error=invalid_scope&error_description=invalid%20scope&state=xx...xx&providerId=yahoo.com

Expected Results:

• Yahoo authentication should be successful.

Relevant Code:

if ([provider isEqualToString:@"yahoo"]) {
          [providers addObject:[FUIOAuth yahooAuthProvider]];
      }