Eliminate unnecessary starting of credential save activity for anti-social providers (#1243)

Author: samtstern

auth/src/main/java/com/firebase/ui/auth/ui/idp/AuthMethodPickerActivity.java

@@ -162,12 +162,27 @@ private void populateIdpList(List<IdpConfig> providerConfigs,
                     this, R.string.fui_progress_dialog_loading) {
                 @Override
                 protected void onSuccess(@NonNull IdpResponse response) {
-                    handler.startSignIn(response);
+                    handleResponse(response);
                 }
 
                 @Override
                 protected void onFailure(@NonNull Exception e) {
-                    handler.startSignIn(IdpResponse.from(e));
+                    handleResponse(IdpResponse.from(e));
+                }
+
+                private void handleResponse(@NonNull IdpResponse response) {
+                    if (!response.isSuccessful()) {
+                        // We have no idea what provider this error stemmed from so just forward
+                        // this along to the handler.
+                        handler.startSignIn(response);
+                    } else if (AuthUI.SOCIAL_PROVIDERS.contains(response.getProviderType())) {
+                        handler.startSignIn(response);
+                    } else {
+                        // Email or phone: the credentials should have already been saved so simply
+                        // move along.
+                        finish(response.isSuccessful() ? RESULT_OK : RESULT_CANCELED,
+                                response.toIntent());
+                    }
                 }
             });
 

auth/src/main/java/com/firebase/ui/auth/viewmodel/idp/SocialProviderResponseHandler.java

@@ -7,6 +7,7 @@
 import android.support.annotation.Nullable;
 import android.support.annotation.RestrictTo;
 
+import com.firebase.ui.auth.AuthUI;
 import com.firebase.ui.auth.ErrorCodes;
 import com.firebase.ui.auth.FirebaseUiException;
 import com.firebase.ui.auth.IdpResponse;
@@ -24,7 +25,6 @@
 import com.google.firebase.auth.AuthResult;
 import com.google.firebase.auth.EmailAuthProvider;
 import com.google.firebase.auth.FirebaseAuthUserCollisionException;
-import com.google.firebase.auth.PhoneAuthProvider;
 
 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
 public class SocialProviderResponseHandler extends AuthViewModelBase<IdpResponse> {
@@ -37,10 +37,9 @@ public void startSignIn(@NonNull final IdpResponse response) {
             setResult(Resource.<IdpResponse>forFailure(response.getError()));
             return;
         }
-        if (response.getProviderType().equals(EmailAuthProvider.PROVIDER_ID)
-                || response.getProviderType().equals(PhoneAuthProvider.PROVIDER_ID)) {
-            setResult(Resource.forSuccess(response));
-            return;
+        if (!AuthUI.SOCIAL_PROVIDERS.contains(response.getProviderType())) {
+            throw new IllegalStateException(
+                    "This handler cannot be used with email or phone providers");
         }
         setResult(Resource.<IdpResponse>forLoading());
 

auth/src/test/java/com/firebase/ui/auth/viewmodel/SocialProviderResponseHandlerTest.java

@@ -91,17 +91,15 @@ public void testSignInIdp_success() {
                 .onChanged(argThat(ResourceMatchers.<IdpResponse>isSuccess()));
     }
 
-    @Test
-    public void testSignInNonIdp_success() {
+    @Test(expected = IllegalStateException.class)
+    public void testSignInNonIdp_failure() {
         mHandler.getOperation().observeForever(mResultObserver);
 
         IdpResponse response = new IdpResponse.Builder(new User.Builder(
                 EmailAuthProvider.PROVIDER_ID, TestConstants.EMAIL).build())
                 .build();
 
         mHandler.startSignIn(response);
-
-        verify(mResultObserver).onChanged(argThat(ResourceMatchers.<IdpResponse>isSuccess()));
     }
 
     @Test