fix: #1426

[kahirokunn]

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

The PR fulfills these requirements:

• It's submitted to the dev branch.
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx[,#xxx], where "xxx" is the issue number)
• All tests are passing: https://github.com/vuejs/vue-test-utils/blob/dev/.github/CONTRIBUTING.md#development-setup
• New/updated tests are included

If adding a new feature, the PR's description includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)

Other information:

Closes #1426

[kahirokunn]

@lmiller1990 よろしくおねがいします！

[lmiller1990]

This is just typing for the props definitions, right? Can you give an example of what this actually does (eg does this give better VSCode suggestions?)

[kahirokunn]

I wrote the test code like this.
https://gist.github.com/kahirokunn/a15c911cbad33082afb41cc861524c2d

I got the error in there

const wrapper = shallowMount(functionalComponent, { localVue, propsData: { tag: 'p' } })

because functionalComponent type is not FunctionalComponentOptions<Record<any, any>>
my functionalComponent type is FunctionalComponentOptions<{ tag: string }>
FunctionalComponentOptions approve to inject Generics.
so I fixed vue test utils type definition.

[lmiller1990]

Right, makes sense. Seems fine to me. Will give it a try and merge this up tomorrow.

[kahirokunn]

Thank you!

[lmiller1990]

Forgot about this... it looks fine, let's merge it up. I am not sure when this will be released - probably during Feb sometime.

VTU for V3 will be much more TS friendly - I might ask for your help with some of the definitions 🤔