Expose typings for Plugins

[posva]

I think it would be helpful to expose the Instance type so plugins can type the argument (https://vue-test-utils.vuejs.org/v2/guide/plugins.html#writing-a-plugin) as well as adapting the install function to infer the options parameter:

    install(handler: (instance: Instance) => Record<string, any>, options?: Record<string, any>): void;

Similar to vuejs/core#2758

[lmiller1990]

Oh cool, this is a good idea. I will give this one at try. If you want to make a PR before I do, go for it 👍

[lmiller1990]

Just to confirm @posva, are you referring to

• the plugin system that only exists in VTU for extending wrapper (which you linked to)?
• as opposed to plugins as in app.use (like #2758)?

We should probably support both with correct types where possible.

[lmiller1990]

Edit: Seems VTU plugins was not actually working properly in the first place, fixed: #276

Are you using this for the mock router? Sorry I did not have time to work on that lately... :(

[posva]

the plugin system that only exists in VTU for extending wrapper (which you linked to)?

Yes!
Specifically, one should be able to do something like this:

function myPlugin(wrapper: Instance, options: { n: number }) {}

// @ts-error
config.plugins.VueWrapper.install(myPlugin, {n: true})

That's why I was referring to https://github.com/vuejs/vue-next/pull/2758/files

I haven't had much time for the router mock, no worries. I was trying to release an initial version soon to get some feedback from the community and add features

[lmiller1990]

Cool, I can update the typings on top of #276.

No problem, I will try test the mock router soon (or have a hack on it if it's not ready yet).

[posva]

Sorry for the delay! I submitted a PR
I'm finishing up an initial 0.0.1 version for the mock but at the end I don't think I need even need the plugin API. But It could be useful in the future to add functions to the wrapper or even the router!