test: included missing PlungerCubitTest

packages/pinball_components/test/src/components/plunger/cubit/plunger_cubit_test.dart

@@ -0,0 +1,25 @@
+import 'package:bloc_test/bloc_test.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pinball_components/pinball_components.dart';
+
+void main() {
+  group('PlungerCubit', () {
+    test('can be instantiated', () {
+      expect(PlungerCubit(), isA<PlungerCubit>());
+    });
+
+    blocTest<PlungerCubit, PlungerState>(
+      'overrides previous pulling state',
+      build: PlungerCubit.new,
+      act: (cubit) => cubit
+        ..pulled()
+        ..autoPulled()
+        ..pulled(),
+      expect: () => [
+        PlungerState.pulling,
+        PlungerState.autoPulling,
+        PlungerState.pulling,
+      ],
+    );
+  });
+}