Undocumented breaking change in hover?

[Parnswir]

Hi there,

we've recently upgraded to v14 from v13.5 and experienced a breaking test that seems to be an undocumented breaking change. I'm starting this discussion to make sure if it was intended or not. I don't have a reproduction repo (yet), so please bear with me.

The environment is Nextjs / next-jest / jsdom. We have a Tippy (tooltip on hover) on a container element like this:

<Tippy content={<div>Tooltip Content</div>}>
  <div>
    <div>
      <span>Nested Content</span>
    </div>
  </div>
</Tippy>

=> hovering on "Nested Content" or any of its parents triggers a tooltip "Tooltip Content" to be shown.

We tested it like this in v13.5:

it("should show a tooltip when hovering", async () => {
  const element = screen.getByText("Nested Content");
  userEvent.hover(element);
  expect(await screen.findByText("Tooltip Content")).toBeInTheDocument();
});

In v14 it should be like this:

it("should show a tooltip when hovering", async () => {
  const element = screen.getByText("Nested Content");
  await userEvent.hover(element);
  expect(await screen.findByText("Tooltip Content")).toBeInTheDocument();
});

But this actually fails to trigger the tooltip.

If we use .parentElement, the test passes again:

it("should show a tooltip when hovering", async () => {
  const element = screen.getByText("Nested Content");
  await userEvent.hover(element.parentElement.parentElement);
  expect(await screen.findByText("Tooltip Content")).toBeInTheDocument();
});

I noticed that hover used to iterate over the target's parent elements in v13.5 but doesn't seem to do that in v14. I don't see any mention of this in the docs, so was that intended behavior that broke with the new version or was it never intended to behave that way?

[ph-fritsche]

With the previous version the user could not express moving from one element to another.
v14 introduced the .pointer() API which tries to emulate pointer device behavior. The implementations of the pointer-related APIs have been replaced by internal calls to .pointer().
Just copying the iteration would have been a bug in the new API.
pointerenter is not dispatched on all parents when moving over an element, but on each element when a pointing device is moved into the hit test boundaries of an element or one of its descendants.

Finding the closest common ancestor when moving from one element to another, and dispatching enter respectively leave on the elements in between might be an appropriate implementation.
But edge cases must be considered before bringing in such a feature, as we don't want to break it / require a major version bump.

An issue collecting information about this and discussing the constraints of this or any other implementation would be welcome.

https://codesandbox.io/s/pointer-enter-leave-dom-mgzuzv