adding tests for pinball dpad button

packages/pinball_ui/test/src/widgets/pinball_dpad_button_test.dart

@@ -0,0 +1,120 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
+import 'package:pinball_ui/gen/gen.dart';
+import 'package:pinball_ui/pinball_ui.dart';
+
+extension _WidgetTesterX on WidgetTester {
+  Future<void> pumpButton({
+    required PinballDpadDirection direction,
+    required VoidCallback onTap,
+  }) async {
+    await pumpWidget(
+      MaterialApp(
+        home: Scaffold(
+          body: PinballDpadButton(
+            direction: direction,
+            onTap: onTap,
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+extension _CommonFindersX on CommonFinders {
+  Finder byImagePath(String path) {
+    return find.byWidgetPredicate(
+      (widget) {
+        if (widget is Image) {
+          final image = widget.image;
+
+          if (image is AssetImage) {
+            return image.keyName == path;
+          }
+          return false;
+        }
+
+        return false;
+      },
+    );
+  }
+}
+
+abstract class _VoidCallbackStubBase {
+  void onCall();
+}
+
+class _VoidCallbackStub extends Mock implements _VoidCallbackStubBase {}
+
+void main() {
+  group('PinballDpadButton', () {
+      testWidgets('can be tapped', (tester) async {
+        final stub = _VoidCallbackStub();
+        await tester.pumpButton(
+          direction: PinballDpadDirection.up,
+          onTap: stub.onCall,
+        );
+
+        await tester.tap(find.byType(Image));
+
+        verify(stub.onCall).called(1);
+      });
+
+    group('when it is up', () {
+      testWidgets('renders the correct image', (tester) async {
+        await tester.pumpButton(
+          direction: PinballDpadDirection.up,
+          onTap: () {},
+        );
+
+        expect(
+          find.byImagePath(Assets.images.button.dpadUp.keyName),
+          findsOneWidget,
+        );
+      });
+    });
+
+    group('when it is down', () {
+      testWidgets('renders the correct image', (tester) async {
+        await tester.pumpButton(
+          direction: PinballDpadDirection.down,
+          onTap: () {},
+        );
+
+        expect(
+          find.byImagePath(Assets.images.button.dpadDown.keyName),
+          findsOneWidget,
+        );
+      });
+    });
+
+    group('when it is left', () {
+      testWidgets('renders the correct image', (tester) async {
+        await tester.pumpButton(
+          direction: PinballDpadDirection.left,
+          onTap: () {},
+        );
+
+        expect(
+          find.byImagePath(Assets.images.button.dpadLeft.keyName),
+          findsOneWidget,
+        );
+      });
+    });
+
+    group('when it is right', () {
+      testWidgets('renders the correct image', (tester) async {
+        await tester.pumpButton(
+          direction: PinballDpadDirection.right,
+          onTap: () {},
+        );
+
+        expect(
+          find.byImagePath(Assets.images.button.dpadRight.keyName),
+          findsOneWidget,
+        );
+      });
+    });
+  });
+}