Create widget_timer_button_test.dart

test/widget_timer_button_test.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:smoke_cess_app/widgets/timer_button.dart';
+
+void main() {
+  testWidgets('TimerButton should display icon & color and react to click', (WidgetTester tester) async {
+    // Define the icon and color
+    final Icon icon = Icon(Icons.play_arrow);
+    final Color color = Colors.green;
+
+    // Build the TimerButton
+    var clicked = false;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: TimerButton(
+          onClicked: () => clicked = true,
+          icon: icon,
+          color: color,
+        ),
+      ),
+    );
+
+    // Verify that the icon and color are displayed
+    expect(find.byWidgetPredicate((widget) => widget is CircleAvatar && widget.child == icon ), findsOneWidget);
+
+    expect(find.byWidgetPredicate((widget) => widget is CircleAvatar && widget.backgroundColor == color ), findsOneWidget);
+
+    // Tap the button
+    await tester.tap(find.byType(InkWell));
+    await tester.pump();
+
+    // Verify that the onClicked callback was called
+    expect(clicked, true);
+  });
+}