Updated the button.icon factory constructors for NNBD (#69596)

packages/flutter/lib/src/material/elevated_button.dart

@@ -82,13 +82,13 @@ class ElevatedButton extends ButtonStyleButton {
   ///
   /// The [icon] and [label] arguments must not be null.
   factory ElevatedButton.icon({
-    Key key,
-    required VoidCallback onPressed,
-    VoidCallback onLongPress,
-    ButtonStyle style,
-    FocusNode focusNode,
-    bool autofocus,
-    Clip clipBehavior,
+    Key? key,
+    required VoidCallback? onPressed,
+    VoidCallback? onLongPress,
+    ButtonStyle? style,
+    FocusNode? focusNode,
+    bool? autofocus,
+    Clip? clipBehavior,
     required Widget icon,
     required Widget label,
   }) = _ElevatedButtonWithIcon;

packages/flutter/lib/src/material/outlined_button.dart

@@ -79,13 +79,13 @@ class OutlinedButton extends ButtonStyleButton {
   ///
   /// The [icon] and [label] arguments must not be null.
   factory OutlinedButton.icon({
-    Key key,
-    required VoidCallback onPressed,
-    VoidCallback onLongPress,
-    ButtonStyle style,
-    FocusNode focusNode,
-    bool autofocus,
-    Clip clipBehavior,
+    Key? key,
+    required VoidCallback? onPressed,
+    VoidCallback? onLongPress,
+    ButtonStyle? style,
+    FocusNode? focusNode,
+    bool? autofocus,
+    Clip? clipBehavior,
     required Widget icon,
     required Widget label,
   }) = _OutlinedButtonWithIcon;

packages/flutter/lib/src/material/text_button.dart

@@ -86,13 +86,13 @@ class TextButton extends ButtonStyleButton {
   ///
   /// The [icon] and [label] arguments must not be null.
   factory TextButton.icon({
-    Key key,
-    required VoidCallback onPressed,
-    VoidCallback onLongPress,
-    ButtonStyle style,
-    FocusNode focusNode,
-    bool autofocus,
-    Clip clipBehavior,
+    Key? key,
+    required VoidCallback? onPressed,
+    VoidCallback? onLongPress,
+    ButtonStyle? style,
+    FocusNode? focusNode,
+    bool? autofocus,
+    Clip? clipBehavior,
     required Widget icon,
     required Widget label,
   }) = _TextButtonWithIcon;

packages/flutter/test/material/elevated_button_test.dart

@@ -11,7 +11,7 @@ import '../rendering/mock_canvas.dart';
 import '../widgets/semantics_tester.dart';
 
 void main() {
-  testWidgets('ElevatedButton defaults', (WidgetTester tester) async {
+  testWidgets('ElevatedButton, ElevatedButton.icon defaults', (WidgetTester tester) async {
     const ColorScheme colorScheme = ColorScheme.light();
 
     // Enabled ElevatedButton
@@ -27,13 +27,13 @@ void main() {
       ),
     );
 
-    final Finder rawButtonMaterial = find.descendant(
+    final Finder buttonMaterial = find.descendant(
       of: find.byType(ElevatedButton),
       matching: find.byType(Material),
     );
 
 
-    Material material = tester.widget<Material>(rawButtonMaterial);
+    Material material = tester.widget<Material>(buttonMaterial);
     expect(material.animationDuration, const Duration(milliseconds: 200));
     expect(material.borderOnForeground, true);
     expect(material.borderRadius, null);
@@ -56,7 +56,7 @@ void main() {
     expect(inkFeatures, paints..circle(color: colorScheme.onPrimary.withAlpha(0x3d))); // splash color is onPrimary(0.24)
 
     // Only elevation changes when enabled and pressed.
-    material = tester.widget<Material>(rawButtonMaterial);
+    material = tester.widget<Material>(buttonMaterial);
     expect(material.animationDuration, const Duration(milliseconds: 200));
     expect(material.borderOnForeground, true);
     expect(material.borderRadius, null);
@@ -74,6 +74,42 @@ void main() {
     await gesture.up();
     await tester.pumpAndSettle();
 
+    // Enabled ElevatedButton.icon
+    final Key iconButtonKey = UniqueKey();
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData.from(colorScheme: colorScheme),
+        home: Center(
+          child: ElevatedButton.icon(
+            key: iconButtonKey,
+            onPressed: () { },
+            icon: const Icon(Icons.add),
+            label: const Text('label'),
+          ),
+        ),
+      ),
+    );
+
+    final Finder iconButtonMaterial = find.descendant(
+      of: find.byKey(iconButtonKey),
+      matching: find.byType(Material),
+    );
+
+    material = tester.widget<Material>(iconButtonMaterial);
+    expect(material.animationDuration, const Duration(milliseconds: 200));
+    expect(material.borderOnForeground, true);
+    expect(material.borderRadius, null);
+    expect(material.clipBehavior, Clip.none);
+    expect(material.color, colorScheme.primary);
+    expect(material.elevation, 2);
+    expect(material.shadowColor, const Color(0xff000000));
+    expect(material.shape, RoundedRectangleBorder(borderRadius: BorderRadius.circular(4)));
+    expect(material.textStyle!.color, colorScheme.onPrimary);
+    expect(material.textStyle!.fontFamily, 'Roboto');
+    expect(material.textStyle!.fontSize, 14);
+    expect(material.textStyle!.fontWeight, FontWeight.w500);
+    expect(material.type, MaterialType.button);
+
     // Disabled ElevatedButton
     await tester.pumpWidget(
       MaterialApp(
@@ -90,7 +126,7 @@ void main() {
     // Finish the elevation animation, final background color change.
     await tester.pumpAndSettle();
 
-    material = tester.widget<Material>(rawButtonMaterial);
+    material = tester.widget<Material>(buttonMaterial);
     expect(material.animationDuration, const Duration(milliseconds: 200));
     expect(material.borderOnForeground, true);
     expect(material.borderRadius, null);

packages/flutter/test/material/outlined_button_test.dart

@@ -11,12 +11,7 @@ import '../rendering/mock_canvas.dart';
 import '../widgets/semantics_tester.dart';
 
 void main() {
-  testWidgets('OutlinedButton defaults', (WidgetTester tester) async {
-    final Finder rawButtonMaterial = find.descendant(
-      of: find.byType(OutlinedButton),
-      matching: find.byType(Material),
-    );
-
+  testWidgets('OutlinedButton, OutlinedButton.icon defaults', (WidgetTester tester) async {
     const ColorScheme colorScheme = ColorScheme.light();
 
     // Enabled OutlinedButton
@@ -32,7 +27,12 @@ void main() {
       ),
     );
 
-    Material material = tester.widget<Material>(rawButtonMaterial);
+    final Finder buttonMaterial = find.descendant(
+      of: find.byType(OutlinedButton),
+      matching: find.byType(Material),
+    );
+
+    Material material = tester.widget<Material>(buttonMaterial);
     expect(material.animationDuration, const Duration(milliseconds: 200));
     expect(material.borderOnForeground, true);
     expect(material.borderRadius, null);
@@ -63,7 +63,49 @@ void main() {
     await gesture.up();
     await tester.pumpAndSettle();
     // No change vs enabled and not pressed.
-    material = tester.widget<Material>(rawButtonMaterial);
+    material = tester.widget<Material>(buttonMaterial);
+    expect(material.animationDuration, const Duration(milliseconds: 200));
+    expect(material.borderOnForeground, true);
+    expect(material.borderRadius, null);
+    expect(material.clipBehavior, Clip.none);
+    expect(material.color, Colors.transparent);
+    expect(material.elevation, 0.0);
+    expect(material.shadowColor, const Color(0xff000000));
+    expect(material.shape, RoundedRectangleBorder(
+      side: BorderSide(
+        width: 1,
+        color: colorScheme.onSurface.withOpacity(0.12),
+      ),
+      borderRadius: BorderRadius.circular(4.0),
+    ));
+    expect(material.textStyle!.color, colorScheme.primary);
+    expect(material.textStyle!.fontFamily, 'Roboto');
+    expect(material.textStyle!.fontSize, 14);
+    expect(material.textStyle!.fontWeight, FontWeight.w500);
+    expect(material.type, MaterialType.button);
+
+    // Enabled OutlinedButton.icon
+    final Key iconButtonKey = UniqueKey();
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData.from(colorScheme: colorScheme),
+        home: Center(
+          child: OutlinedButton.icon(
+            key: iconButtonKey,
+            onPressed: () { },
+            icon: const Icon(Icons.add),
+            label: const Text('label'),
+          ),
+        ),
+      ),
+    );
+
+    final Finder iconButtonMaterial = find.descendant(
+      of: find.byKey(iconButtonKey),
+      matching: find.byType(Material),
+    );
+
+    material = tester.widget<Material>(iconButtonMaterial);
     expect(material.animationDuration, const Duration(milliseconds: 200));
     expect(material.borderOnForeground, true);
     expect(material.borderRadius, null);
@@ -97,7 +139,7 @@ void main() {
       ),
     );
 
-    material = tester.widget<Material>(rawButtonMaterial);
+    material = tester.widget<Material>(buttonMaterial);
     expect(material.animationDuration, const Duration(milliseconds: 200));
     expect(material.borderOnForeground, true);
     expect(material.borderRadius, null);

packages/flutter/test/material/text_button_test.dart

@@ -11,7 +11,7 @@ import '../rendering/mock_canvas.dart';
 import '../widgets/semantics_tester.dart';
 
 void main() {
-  testWidgets('TextButton defaults', (WidgetTester tester) async {
+  testWidgets('TextButton, TextButton.icon defaults', (WidgetTester tester) async {
     const ColorScheme colorScheme = ColorScheme.light();
 
     // Enabled TextButton
@@ -72,6 +72,42 @@ void main() {
     expect(material.textStyle!.fontWeight, FontWeight.w500);
     expect(material.type, MaterialType.button);
 
+    // Enabled TextButton.icon
+    final Key iconButtonKey = UniqueKey();
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData.from(colorScheme: colorScheme),
+        home: Center(
+          child: TextButton.icon(
+            key: iconButtonKey,
+            onPressed: () { },
+            icon: const Icon(Icons.add),
+            label: const Text('label'),
+          ),
+        ),
+      ),
+    );
+
+    final Finder iconButtonMaterial = find.descendant(
+      of: find.byKey(iconButtonKey),
+      matching: find.byType(Material),
+    );
+
+    material = tester.widget<Material>(iconButtonMaterial);
+    expect(material.animationDuration, const Duration(milliseconds: 200));
+    expect(material.borderOnForeground, true);
+    expect(material.borderRadius, null);
+    expect(material.clipBehavior, Clip.none);
+    expect(material.color, Colors.transparent);
+    expect(material.elevation, 0.0);
+    expect(material.shadowColor, const Color(0xff000000));
+    expect(material.shape, RoundedRectangleBorder(borderRadius: BorderRadius.circular(4.0)));
+    expect(material.textStyle!.color, colorScheme.primary);
+    expect(material.textStyle!.fontFamily, 'Roboto');
+    expect(material.textStyle!.fontSize, 14);
+    expect(material.textStyle!.fontWeight, FontWeight.w500);
+    expect(material.type, MaterialType.button);
+
     // Disabled TextButton
     await tester.pumpWidget(
       MaterialApp(