fix(types): fix ThisType of component options with no props option

[ktsn]

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 for v2.x (or to a previous version branch), not the master 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/blob/dev/.github/CONTRIBUTING.md#development-setup
• New/updated tests are included

Other information:

Previously, if the user does not include props option in component options, ThisType has Record<string, any> in the members of intersection types. Then this.notExistingProperty is already passed if props options is missed.

export default Vue.extend({
  data() {
    this.notExistingProperty // <- this should be an error but currently isn't.
  }
})

I added a default type parameter of Vue.component and Vue.extend to avoid to allow any properties in ThisType when there is no props option.

I did not add a test for this because we need to check a compilation error to confirm that 😛

[HerringtonDarkholme]

Thanks! IIRC the default never is removed by me because some usages cannot be compiled.

But it might be caused by other typing and I've mistaken it with never. I need some more experiment to confirm it.

[HerringtonDarkholme]

I have investigated this issue; a lot of compiling error in TS2.6.1, :(

It turns out that never bound isn't the culprit but Component.

Component is declared as the union of two ThisTyped options. This makes ComponentOptions not assignable to Component.

So this is a good fix! Thanks!

And I will make a pull request to fix Component issue.

[ktsn]

@HerringtonDarkholme Thanks for investigation!
I'm closing this PR in favor of #7135 🙂