✅ add tests for DebugFloatingThemeButton.

test/debug_floating_theme_buttons_test.dart

@@ -0,0 +1,81 @@
+/*
+ * // Copyright © 2020 Birju Vachhani. All rights reserved.
+ * // Use of this source code is governed by an Apache license that can be
+ * // found in the LICENSE file.
+ */
+
+import 'package:adaptive_theme/adaptive_theme.dart';
+import 'package:adaptive_theme/src/debug_floating_theme_buttons.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'test_utils.dart';
+
+void main() {
+  testWidgets('debugShowFloatingThemeButton test', (tester) async {
+    final light = ThemeData.light();
+    final dark = ThemeData.dark();
+    await pumpMaterialApp(
+      tester,
+      light: light,
+      dark: dark,
+      mode: AdaptiveThemeMode.light,
+      debugShowFloatingThemeButton: true,
+    );
+
+    final widget = tester.widget<DebugFloatingThemeButton>(
+        find.byType(DebugFloatingThemeButton));
+    expect(widget.debugShow, isTrue);
+  });
+
+  testWidgets('DebugFloatingThemeButton show/hide test', (tester) async {
+    final light = ThemeData.light();
+    final dark = ThemeData.dark();
+    await pumpMaterialApp(
+      tester,
+      light: light,
+      dark: dark,
+      mode: AdaptiveThemeMode.light,
+      debugShowFloatingThemeButton: true,
+    );
+
+    final BuildContext context = tester.element(find.byType(Scaffold));
+    final manager = AdaptiveTheme.of(context);
+
+    final widgetFinder = find.byType(DebugFloatingThemeButton);
+    final dragIndicatorFinder = find.descendant(
+        of: widgetFinder, matching: find.byIcon(Icons.drag_indicator_rounded));
+
+    final widget = tester.widget<DebugFloatingThemeButton>(widgetFinder);
+    expect(widget.debugShow, isTrue);
+
+    final rect = tester.getRect(dragIndicatorFinder);
+    await tester.tapAt(rect.center);
+    await tester.pumpAndSettle();
+
+    final toggleButtonFinder =
+        find.descendant(of: widgetFinder, matching: find.byType(ToggleButtons));
+    ToggleButtons buttonsWidget() =>
+        tester.widget<ToggleButtons>(toggleButtonFinder);
+
+    // check if light theme is selected
+    expect(
+        buttonsWidget().isSelected, containsAllInOrder([true, false, false]));
+
+    // select dark theme
+    buttonsWidget().onPressed?.call(1);
+    await tester.pumpAndSettle();
+
+    expect(manager.mode, AdaptiveThemeMode.dark);
+    expect(
+        buttonsWidget().isSelected, containsAllInOrder([false, true, false]));
+
+    // select system theme
+    buttonsWidget().onPressed?.call(2);
+    await tester.pumpAndSettle();
+
+    expect(manager.mode, AdaptiveThemeMode.system);
+    expect(
+        buttonsWidget().isSelected, containsAllInOrder([false, false, true]));
+  });
+}

test/test_utils.dart

@@ -20,11 +20,13 @@ Future<void> pumpMaterialApp(
   required ThemeData light,
   required ThemeData dark,
   required AdaptiveThemeMode mode,
+  bool? debugShowFloatingThemeButton,
 }) async {
   await tester.pumpWidget(AdaptiveTheme(
     light: light,
     dark: dark,
     initial: mode,
+    debugShowFloatingThemeButton: debugShowFloatingThemeButton ?? false,
     builder: (light, dark) => MaterialApp(
       theme: light,
       darkTheme: dark,