[demolaf]

• Related to Customizable SwiftUI auth UI: content slots, per-screen state, and theming #1400

Adds public EnterPhoneNumberScreen and EnterVerificationCodeScreen, so apps can draw the phone sign-in screens themselves while the library keeps sending codes, signing in, navigating and reporting errors. Stacked on #1411.

Changes

• Each screen owns its input state and passes its content a PhoneNumberContentState or VerificationCodeContentState: Bindings for input, closures for actions, plus isValid, isLoading and a localized errorMessage.
• DefaultEnterPhoneNumberContent and DefaultEnterVerificationCodeContent hold the stock markup, and the existing internal views now render them through the screens.
• The verification screen adds Resend Code with a 60 second countdown, matching the Android phone screen.
• Verifying now goes through signIn(credentials:), so phone sign-in with MFA reaches the resolution screen instead of dropping the challenge.
• isLoading now covers sending the code, which previously showed no progress and allowed repeated taps.

API Usage

AuthPickerView { authenticatedApp }
  .pickerDestination { screen in
    switch screen {
    case .enterPhoneNumber:
      EnterPhoneNumberScreen { state in
        TextField("Phone number", text: state.phoneNumber)
        if let errorMessage = state.errorMessage {
          Text(errorMessage)
        }
        Button("Send code", action: state.sendCode)
          .disabled(!state.isValid || state.isLoading)
      }
    case let .enterVerificationCode(verificationID, fullPhoneNumber):
      EnterVerificationCodeScreen(
        verificationID: verificationID,
        fullPhoneNumber: fullPhoneNumber
      ) { state in
        DefaultEnterVerificationCodeContent(state: state)
          .background(.yellow.opacity(0.1))
      }
    default:
      DefaultAuthPickerDestination(screen: screen)
    }
  }

Preview

Default, with resend countdown	Custom content showing errorMessage

---

Maintainer note: Fixes internal CPRN-518

[gemini-code-assist]

Code Review

This pull request refactors the phone authentication views by separating state management and business logic from the UI layout. It introduces EnterPhoneNumberScreen and EnterVerificationCodeScreen to handle state and actions, delegating rendering to customizable content views like DefaultEnterPhoneNumberContent and DefaultEnterVerificationCodeContent. A critical bug was identified in EnterVerificationCodeScreen where the navigation stack is cleared when multi-factor authentication is required but no MFA handler is configured.

[gemini-code-assist]

If outcome is .mfaRequired but mfaHandler is nil, the code currently falls through and calls authService.navigator.clear(). This is a bug because the user is not actually signed in yet (MFA is still required), but the navigation stack is cleared as if sign-in succeeded. We should handle this case by reporting an error and keeping the user on the verification screen.

Suggested change

	if case let .mfaRequired(mfaInfo) = outcome, let onMFA = mfaHandler {
	onMFA(mfaInfo)
	return
	}
	authService.navigator.clear()
	switch outcome {
	case let .mfaRequired(mfaInfo):
	if let onMFA = mfaHandler {
	onMFA(mfaInfo)
	} else {
	let error = AuthServiceError.multiFactorAuth("Multi-factor authentication is required, but no MFA handler is configured.")
	errorMessage = error.localizedDescription
	reportError?(error)
	}
	case .signedIn:
	authService.navigator.clear()
	}