fix(auth): complete MFA challenge sign-in navigation and success callback

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.

[demolaf]

A successful MFA challenge left the screen blank and never invoked onSignInSuccess. The MfaChallenge route read pendingResolver directly during composition, so clearing it on success dropped the route into its else branch and called navController.popBackStack() from the composable body — emptying the back stack, which NavHost renders as nothing. The callback was lost separately, because onSuccess discarded the resolved AuthResult and reset the state to AuthState.Idle.

The resolver is now retained for the back-stack entry with remember, so the challenge stays painted through the exit transition and the pop is no longer reachable on the success path. onSuccess routes the result through updateAuthStateWithResult, the same path every other provider already uses, so onSignInSuccess receives the AuthResult.

Added FirebaseAuthScreenMfaSuccessTest covering both defects plus the RequiresEmailVerification branch the fix routes through — verified the two success cases fail on the old code and pass with the fix.

---

Maintainer note: Fixes internal CPRN-382

[gemini-code-assist]

Code Review

This pull request improves the MFA challenge success path in FirebaseAuthScreen by retaining the resolver during exit transitions and correctly routing the resolved AuthResult to trigger onSignInSuccess. It also introduces a comprehensive suite of regression tests. Feedback points out a critical issue where using remember without keys can permanently cache null during activity recreation (such as screen rotation), which would prematurely kick the user out of the MFA flow. A robust caching strategy is suggested to resolve this.