docs: Add basic configuration

[afontcu]

VTU should be quite plug-and-play as long as you install it in a Vue project (what other projects would want to use VTU? 🤔).

Thus, this section should be really thin so people can start to write tests as soon as possible.

Thoughts:

• provide basic steps for Vue 3 + VTU + Jest
• provide a demo repo with config
• point to @vue/cli and its VTU plugin (should we discuss this?)
• provide config for common scenarios (asset stubbing, for instance?)

[lmiller1990]

I added something very minimal here for the first two steps https://github.com/vuejs/vue-test-utils-next-docs/blob/master/src/guide/installation.md

It is not polished at all but it's enough to get started with VTU next. The first line is a lie - vtu next is not on NPM yet, was just getting ready.

We should probably work with sodatea to get a vue-cli plugin with vue-jest next (aka vue-jest 5) and vtu next.

[dobromir-hristov]

Contrary to belief, I have gotten many questions, probably you as well, on how to setup VTU with Jest/Mocha/SomethingNoOneEverUsed.js even with the old docs having sections for that.

I dont think this will change. I would not go into setting up my own webpack setup, but then again people use Rollup or Parcel, so rough guidelines are necessary I think.

[lmiller1990]

Hm, Vue itself does not provide docs on how to configure webpack/parcel/vue-loader.

We could provide something generic (since these kind of specific guides tend to get out of date first). The ideas are the same for all runners. So something along the lines of:

• VTU requires a DOM environment to run. Most commonly used it jsdom. document must be globally available before using VTU.
• Your test runner needs to understand vue files. Jest uses vue-jest, and webpack-based runners (mocha-webpack) can use vue-loader.
• Here is a basic template using Jest and Webpack

Low on implementation details, just a few sentences explaining the basic and a link or two to some working templates so people can get going asap.

I have a basic template here we could clean up and use.

Also we should work on a cli-plugin.

[dobromir-hristov]

yeah, as long as we explain why those are needed in a few words, thats more than enough :) We will always have to reply to such questions hehe

[JessicaSachs]

I'm happy to take a stab at the setup/environment/configuration part of the docs

[lmiller1990]

Sure! Thanks.