wrapper.vm.hasFocus returns opposite value starting in v1.1.3

[pechitook]

Subject of the issue

We have a very simple test that makes the following assertion

it('Shows options when component is focused', async () => {
    const input = wrapper.find('input');
    await input.trigger('focus');

    expect(wrapper.vm.hasFocus).toBe(true);
});

With @vue/test-utils@1.1.2 this assertion pass. Starting from 1.1.3 and all the way to 1.2.0 (I tested all releases in between) the wrapper.vm.hasFocus assertion returns false.

Steps to reproduce

Shallow mount a component that has an input, then try to focus it:

it('Shows options when component is focused', async () => {
    const input = wrapper.find('input');
    await input.trigger('focus');

    expect(wrapper.vm.hasFocus).toBe(true);
});

Expected behaviour

What should happen?
hasFocus should return a consistent result from v1.1.2 to v1.1.3

Actual behaviour

What happens instead?
hasFocus now returns the opposite value without the test changing

Possible Solution

None of the changes in the release note ring a bell to me about why this may occur :(

What are the alternative solutions? Please describe what else you have considered?

[lmiller1990]

This same up recently, please see this #1848 and this #1777 (comment).

[lmiller1990]

Did the above links fix your problem?

[pechitook]

Adding attachTo: document.body effectively fixed this. Thank you!! 🎉