Unit test support

[simonwalsh]

Re: #20

Context: we want to bake in the support for unit testing in the host app, using Ava!

Steps:

• (temp): run yarn add ava -save to the host app
• run yarn to the tool app
• add a folder in the host app called specs on the root
• add tests in that folder and anything with the .js extension will get picked up by ava
• from the host app, run yarn test and voila!

More:

• to use custom configs in the host app, you can follow the steps here but not that the test folder will always need to be called specs
• you can also pass flags to ava using yarn test -- --watch (using watch for example)

[simonwalsh]

@nddery So apparently, we need to use babel to transpile the dependencies before ava can use them so I'm not done yet I guess!

[simonwalsh]

Yeah... Not entirely sure how to go about that...

https://github.com/avajs/ava/blob/master/docs/recipes/babelrc.md#configuring-babel

I feel like we are trying to use Ava in a very unconventional way here...

Thoughts @nddery ?

[simonwalsh]

Okay, just did some testing and the only way that I manage to have it working is by...

1. adding all of this to the package.json of the project (might be solved when we have a proper npm package):

    "babel-cli": "^6.24.1",
    "babel-loader": "^7.0.0",
    "babel-preset-env": "^1.4.0",
    "babel-register": "^6.24.1",

2. adding this line at the top of every test (before what needs to be transpiled):

import 'babel-register';

3. adding a .babelrc file to the project with these settings:

{
  "presets": ["env"]
}

IMO this makes having ava configured in the tool kinda useless. I would rather give the user the opportunity to set it in their own project then.. not sure!

[nddery]

mmh.. not sure either.. tried a couple of things on my end but to no avail.. I don't know tbh..

[simonwalsh]

I will refactor to see if we couldn't use Jest and this technique jestjs/jest#1468 (comment)