fix(ui_auth): allow to pass EmailFormStyle via property (#98)

Author: lesnitsky

packages/firebase_ui_auth/lib/src/widgets/email_form.dart

@@ -100,6 +100,37 @@ class EmailForm extends StatelessWidget {
   /// A label that would be used for the "Sign in" button.
   final String? actionButtonLabelOverride;
 
+  /// An object that is being used to apply styling configuration to the email
+  /// form.
+  ///
+  /// Alternatively [FirebaseUITheme] could be used to provide styling
+  /// configuration.
+  /// ```dart
+  /// runApp(
+  ///   const FirebaseUITheme(
+  ///     styles: {
+  ///       EmailFormStyle(signInButtonVariant: ButtonVariant.text),
+  ///     },
+  ///     child: MaterialApp(
+  ///       home: MyScreen(),
+  ///     ),
+  ///   ),
+  /// );
+  ///
+  /// class MyScreen extends StatelessWidget {
+  ///   @override
+  ///   Widget build(BuildContext context) {
+  ///     return Scaffold(
+  ///       appBar: AppBar(
+  ///         title: Text('Email sign in'),
+  ///       ),
+  ///       body: Center(child: EmailForm()),
+  ///     );
+  ///   }
+  /// }
+  /// ```
+  final EmailFormStyle? style;
+
   /// {@macro ui.auth.widgets.email_form}
   const EmailForm({
     super.key,
@@ -109,6 +140,7 @@ class EmailForm extends StatelessWidget {
     this.onSubmit,
     this.email,
     this.actionButtonLabelOverride,
+    this.style,
   });
 
   @override
@@ -120,6 +152,7 @@ class EmailForm extends StatelessWidget {
       email: email,
       onSubmit: onSubmit,
       actionButtonLabelOverride: actionButtonLabelOverride,
+      style: style,
     );
 
     return AuthFlowBuilder<EmailAuthController>(
@@ -143,13 +176,16 @@ class _SignInFormContent extends StatefulWidget {
 
   final String? actionButtonLabelOverride;
 
+  final EmailFormStyle? style;
+
   const _SignInFormContent({
     this.auth,
     this.onSubmit,
     this.action,
     this.email,
     this.provider,
     this.actionButtonLabelOverride,
+    this.style,
   });
 
   @override
@@ -268,10 +304,11 @@ class _SignInFormContentState extends State<_SignInFormContent> {
       Builder(
         builder: (context) {
           final state = AuthState.of(context);
-          final style = FirebaseUIStyle.ofType<EmailFormStyle>(
-            context,
-            const EmailFormStyle(),
-          );
+          final style = widget.style ??
+              FirebaseUIStyle.ofType<EmailFormStyle>(
+                context,
+                const EmailFormStyle(),
+              );
 
           return LoadingButton(
             variant: style.signInButtonVariant,

packages/firebase_ui_auth/test/widgets/email_form_test.dart

@@ -42,18 +42,66 @@ void main() {
       );
     });
 
-    testWidgets('respects the EmailFormStyle', (tester) async {
-      await tester.pumpWidget(
-        FirebaseUITheme(
-          styles: const {
-            EmailFormStyle(signInButtonVariant: ButtonVariant.filled)
-          },
-          child: widget,
-        ),
-      );
+    testWidgets(
+      'respects EmailFormStyle passed to FirebaseUITheme',
+      (tester) async {
+        await tester.pumpWidget(
+          FirebaseUITheme(
+            styles: const {
+              EmailFormStyle(signInButtonVariant: ButtonVariant.filled)
+            },
+            child: widget,
+          ),
+        );
 
-      final button = find.byType(ElevatedButton);
-      expect(button, findsOneWidget);
-    });
+        final button = find.byType(ElevatedButton);
+        expect(button, findsOneWidget);
+      },
+    );
+
+    testWidgets(
+      'respects EmailFormStyle passed via property',
+      (tester) async {
+        await tester.pumpWidget(
+          widget = TestMaterialApp(
+            child: EmailForm(
+              auth: MockAuth(),
+              action: AuthAction.signIn,
+              style: const EmailFormStyle(
+                signInButtonVariant: ButtonVariant.filled,
+              ),
+            ),
+          ),
+        );
+
+        final button = find.byType(ElevatedButton);
+        expect(button, findsOneWidget);
+      },
+    );
+
+    testWidgets(
+      'EmailFormStyle passed via property is higher priority',
+      (tester) async {
+        await tester.pumpWidget(
+          TestMaterialApp(
+            child: FirebaseUITheme(
+              styles: const {
+                EmailFormStyle(signInButtonVariant: ButtonVariant.text)
+              },
+              child: EmailForm(
+                auth: MockAuth(),
+                action: AuthAction.signIn,
+                style: const EmailFormStyle(
+                  signInButtonVariant: ButtonVariant.filled,
+                ),
+              ),
+            ),
+          ),
+        );
+
+        final button = find.byType(ElevatedButton);
+        expect(button, findsOneWidget);
+      },
+    );
   });
 }