Pointer events: Allow hover events from trackpad (#108116)

Author: dkwingsmt

packages/flutter/lib/src/gestures/events.dart

@@ -1035,10 +1035,7 @@ class PointerHoverEvent extends PointerEvent with _PointerEventDescription, _Cop
     super.tilt,
     super.synthesized,
     super.embedderId,
-  }) : // Dart doesn't support comparing enums with == in const contexts yet.
-       // https://github.com/dart-lang/language/issues/1811
-       assert(!identical(kind, PointerDeviceKind.trackpad)),
-       super(
+  }) : super(
          down: false,
          pressure: 0.0,
        );
@@ -1156,7 +1153,9 @@ class PointerEnterEvent extends PointerEvent with _PointerEventDescription, _Cop
     super.down,
     super.synthesized,
     super.embedderId,
-  }) : assert(!identical(kind, PointerDeviceKind.trackpad)),
+  }) : // Dart doesn't support comparing enums with == in const contexts yet.
+       // https://github.com/dart-lang/language/issues/1811
+       assert(!identical(kind, PointerDeviceKind.trackpad)),
        super(
          pressure: 0.0,
        );

packages/flutter/test/gestures/events_test.dart

@@ -844,6 +844,17 @@ void main() {
       expect(event.synthesized, empty.synthesized);
     });
   });
+
+  test('Ensure certain event types are allowed', () {
+    // Regression test for https://github.com/flutter/flutter/issues/107962
+    expect(const PointerHoverEvent(kind: PointerDeviceKind.trackpad), isNotNull);
+
+    // The test passes if it compiles.
+  });
+
+  test('Ensure certain event types are not allowed', () {
+    expect(() => PointerDownEvent(kind: PointerDeviceKind.trackpad), throwsAssertionError);
+  });
 }
 
 void _expectTransformedEvent({