This patch formalizes the mock native events and event sequences used in unit tests.
The `createEventTarget` function returns an object that can be used to dispatch native event sequences on the target without having to manually do so across all the scenarios we need to account for. Unit tests can be written as if we were only working with PointerEvent, but they will dispatch realistic native event sequences based on the execution environment (e.g., is PointerEvent supported?) and pointer type.
```
describe.each(environments)('Suite', (hasPointerEvents) => {
beforeEach(() => {
// setup
});
test.each(pointerTypes)('Test', (pointerType) => {
const target = createEventTarget(node);
target.pointerdown({pointerType});
expect(callback).toBeCalled();
});
});
```
Every native event that is dispatched now includes a complete object by default. The properties of the events can be customized. Properties that shouldn't be relied on in responder implementations are excluded from the mock native events to ensure tests will fail. Equivalent properties are normalized across different event types, e.g., 'pointerId' is converted to 'identifier' before a TouchEvent is dispatched.
1. Run the tests in both an environment without PointerEvent and one with PointerEvent.
2. Improve test coverage to include both mouse and touch pointers.
3. Change 'Press' so that it only listens to either pointer events or fallbacks events.
Separate the PointerEvent and fallback implementations.
Fix the unit tests to cover both PointerEvent and non-PointerEvent environments.
Fix the focus-visible related callbacks to get called when keys other than "Tab" are used.
**Problem**
The existing responders listen to pointer events by default and add fallback events if PointerEvent is not supported. However, this complicates the responders and makes it easy to create a problematic unit test environment. jsdom doesn't support PointerEvent, which means that the responders end up listening to pointer events *and* fallback events in unit tests. This isn't a direct problem in production environments, because no browser will fire pointer events if they aren't supported. But in the unit test environment, we often dispatch event sequences taken from browsers that support pointer events. This means that what we're often testing is actually a (complex) scenario that cannot even occur in production: a responder that is listening to and receives both pointer events and fallback events. Not only does this risk making responders more complicated to implement but it could also hide bugs in implementations.
**Response**
Implement the responders so that they're only listening to *either* pointer events *or* fallback events, never both. This should make the default pointer events implementations significantly simpler and easier to test, as well as free to rely on the complete PointerEvents API. In the future it should also make DCE easier for target environments that are known to support PointerEvents, as we can use build tools with an equivalent of the runtime check. The fallback events (touch and mouse) need to coexist and be resilient to browser emulated events. Our unit tests should express a suite of high-level interactions that can be run in environments with and without PointerEvents support.
Prevents Spacebar from scrolling the window.
Prevents Enter from triggering a navigation if preventDefault is true.
Fixes the emulated mouse events test.
1. Allow auxillary button clicks (i.e., middle mouse button) to trigger 'onPressStart' and 'onPressEnd', but never 'onPress'.
2. Report the button type – 'primary' or 'auxillary' – on the press event.
The responder region calculation logic wasn't updating the deactivation region
during the lifetime of an event instance, causing incorrect behaviour when the
current press ends outside the press target and if the press target has moved
since the last time the first-and-only time the deactivation region was
measured.
* Rename `disableContextMenu` to `preventContextMenu`
* Change the behaviour of `preventContextMenu` so that `onContextMenu` is still called when the native context menu is prevented.
Dominic Gannaway
Nicolas Gallagher
Vincent Riemer
Andrew Clark
Brandon Dail