hover static method Null safety

Hovers over element.

Related: UserEvent.unhover

See: testing-library.com/docs/ecosystem-user-event/#hoverelement

Options

eventInit

Use eventInit to initialize the onMouseOver event.

skipPointerEventsCheck

Attempting to interact with an element that has 'pointer-events: none' set will throw an error. Use skipPointerEventsCheck to prevent that error from being thrown by skipping the check of whether any element in the DOM-tree has 'pointer-events: none' set. In addition, the underlying check for pointer events is costly in general and very costly when rendering large DOM-trees. Can be used to speed up tests.

Example

<div>
  <button>Hover over me!</button>
</div>

import 'package:react/hooks.dart';
import 'package:react/react.dart' as react;
import 'package:react_testing_library/matchers.dart' show isInTheDocument;
import 'package:react_testing_library/react_testing_library.dart' as rtl;
import 'package:react_testing_library/user_event.dart';
import 'package:test/test.dart';

void main() {
  test('', () {
    final HoverButton = react.registerFunctionComponent((props) {
      final isShown = useState(false);
      return react.div({}, [
        react.button({
          'onMouseOver': (_) => isShown.set(true),
          'onMouseOut': (_) => isShown.set(false)
        }, [
          'Hover over me!'
        ]),
        if (isShown.value) react.span({}, ['Hello!']) else null,
      ]);
    });

    // Render the DOM shown in the example snippet above.
    final view = rtl.render(HoverButton({}));

    // Use react_testing_library queries to store references to the node.
    final button = view.getByRole('button');
    expect(view.queryByText('Hello!'), isNull, reason: 'sanity check');

    // Use `UserEvent.hover` to simulate a user mousing over a button.
    UserEvent.hover(button);

    // Use `isInTheDocument` matcher to verify that the new element is present.
    expect(view.getByText('Hello!'), isInTheDocument);
  });
}

Warning About Errors

Unlike the JS API, any uncaught errors thrown during event propagation will get rethrown. This helps surface errors that could otherwise go unnoticed since they aren't printed to the terminal when running tests.

NOTE: render() supports React vDom elements / custom components created using either the react or over_react packages.

The examples shown here use the react package since the react_testing_library does not have a direct dependency on over_react - but both libraries are fully supported.

{@category UserActions}