Fix simulated context menu events not being mouse events

Author: greglittlefield-wf

lib/src/react_client/event_helpers.dart

@@ -783,7 +783,8 @@ extension SyntheticEventTypeHelpers on SyntheticEvent {
       (_hasProperty('relatedTarget') && !_hasProperty('button')) || _checkEventType(const ['focus', 'blur']);
 
   /// Uses Duck Typing to detect if the event instance is a [SyntheticMouseEvent].
-  bool get isMouseEvent => _hasProperty('button') || _checkEventType(const ['mouse', 'click', 'drag', 'drop']);
+  bool get isMouseEvent =>
+      _hasProperty('button') || _checkEventType(const ['mouse', 'click', 'drag', 'drop', 'contextmenu']);
 
   /// Uses Duck Typing to detect if the event instance is a [SyntheticPointerEvent].
   bool get isPointerEvent => _hasProperty('pointerId') || _checkEventType(const ['pointer']);

test/react_test_utils_test.dart

@@ -158,6 +158,8 @@ testUtils({isComponent2: false, dynamic eventComponent, dynamic sampleComponent,
       group('compositionStart', () => testEvent(Simulate.compositionStart, 'compositionStart', expectCompositionEvent));
       group('compositionUpdate',
           () => testEvent(Simulate.compositionUpdate, 'compositionUpdate', expectCompositionEvent));
+      group('contextMenu',
+          () => testEvent(Simulate.contextMenu, 'contextMenu', expectMouseEvent));
       group('cut', () => testEvent(Simulate.cut, 'cut', expectClipboardEvent));
       group('doubleClick', () => testEvent(Simulate.doubleClick, 'doubleClick', expectMouseEvent));
       group('drag', () => testEvent(Simulate.drag, 'drag', expectMouseEvent));

test/test_components.dart

@@ -16,6 +16,7 @@ class EventComponent extends Component {
         'onCompositionEnd': onEvent,
         'onCompositionStart': onEvent,
         'onCompositionUpdate': onEvent,
+        'onContextMenu': onEvent,
         'onCut': onEvent,
         'onDoubleClick': onEvent,
         'onDrag': onEvent,

test/test_components2.dart

@@ -16,6 +16,7 @@ class EventComponent2 extends Component2 {
         'onCompositionEnd': onEvent,
         'onCompositionStart': onEvent,
         'onCompositionUpdate': onEvent,
+        'onContextMenu': onEvent,
         'onCut': onEvent,
         'onDoubleClick': onEvent,
         'onDrag': onEvent,