Add global configuration settings

[dobromir-hristov]

Description

We should allow users to register default global components, directives and plugins, instead of passing to each test all the time.

Detailed

In VTU beta we could add a few global configs. Stubs was the main one with a few more later added.

Components, filters and directives were easy to add globally to all components, you just had to do this in your setup file:

Vue.use(Plugin)
Vue.component(GlobalComponent)
// etc

With Vue 3, you now have a Vue App instance, which means you no longer can add global configuration like that. This would lead to allot of repetition in tests, and large codebases could suffer greatly.

We could provide the same api as we have now in MountOptions.global, just at a global level.

[lmiller1990]

I'd say this makes sense - I see no reason to drop this API.

[lmiller1990]

I wonder if we could also have some kind of plugin system.

VueTestUtils.config = {
  extensions: {
    VueWrapper: {
      findByTestId(vueWrapper, ...args) {
        const selector = args[0]
        return vueWrapper.find(`[data-testid="${selector}"]`)
      }
    } 
  }
}

extensions would have VueWrapper and DOMWrapper. Methods would receive the wrapper as the first arg, followed by the other args. This means they can hook into other Wrapper APIs, like trigger, as part of their extension.

Users could add features. Eg, I like findByTestId, but it might be too opinionated for inclusion in core. Thoughts?

[dobromir-hristov]

Yep, was thinking about it too. This way people can extend as needed, make plugins etc.

[lmiller1990]

Yep love the idea, that way people can get what they want out of the framework. Anyone who has time can investigate this, I think it'll be a fun one

[dobromir-hristov]

I can take a stab at it

[dobromir-hristov]

Here are two ways of doing this, with Prototype extending and with a plugins hook.

https://github.com/vuejs/vue-test-utils-next/compare/feature/extending-without-plugin

[lmiller1990]

Should we make this truly "global" (eg not on wrapper) like in VTU beta? https://vue-test-utils.vuejs.org/api/#config

[dobromir-hristov]

If you are referring to the global configuration in mount I think you should still be able to have these setup on a per-test basis.

That way you can overwrite some global setting for the test.