test(neon): unit test StreamListenable

Signed-off-by: Nikolas Rimikis <rimikis.nikolas@gmail.com>

packages/neon/neon/test/stream_listenable_test.dart

@@ -0,0 +1,73 @@
+// ignore_for_file: unreachable_from_main
+
+import 'dart:async';
+
+import 'package:mocktail/mocktail.dart';
+import 'package:neon/src/utils/stream_listenable.dart';
+import 'package:rxdart/rxdart.dart';
+import 'package:test/test.dart';
+
+class MockCallbackFunction extends Mock {
+  FutureOr<void> call();
+}
+
+void main() {
+  group('StreamListenable', () {
+    test('stream', () async {
+      final stream = BehaviorSubject<bool>();
+      final callback = MockCallbackFunction();
+
+      StreamListenable(stream).addListener(callback.call);
+
+      verifyNever(callback.call);
+
+      stream.value = true;
+      await Future.delayed(const Duration(milliseconds: 100));
+      verify(callback.call).called(1);
+
+      stream.value = true;
+      await Future.delayed(const Duration(milliseconds: 100));
+      verify(callback.call).called(1);
+
+      unawaited(stream.close());
+    });
+
+    test('multiStream', () async {
+      final stream = BehaviorSubject<bool>();
+      final stream2 = BehaviorSubject<int>();
+      final callback = MockCallbackFunction();
+
+      StreamListenable.multiListenable({
+        stream,
+        stream2,
+      }).addListener(callback.call);
+
+      verifyNever(callback.call);
+
+      stream.value = true;
+      await Future.delayed(const Duration(milliseconds: 100));
+      verify(callback.call).called(1);
+
+      stream2.value = 3;
+      await Future.delayed(const Duration(milliseconds: 100));
+      verify(callback.call).called(1);
+
+      unawaited(stream.close());
+      unawaited(stream2.close());
+    });
+
+    test('dispose', () {
+      final controller = StreamController();
+
+      final listenable = StreamListenable(controller.stream);
+
+      expect(controller.hasListener, true);
+
+      // ignore: cascade_invocations
+      listenable.dispose();
+
+      expect(controller.isClosed, false);
+      unawaited(controller.close());
+    });
+  });
+}