Add Unit Tests to core APIs

We have has some regressions slip through using snapshot testing.

We need to have some proper unit testing on the core APIs to ensure regressions don’t slip through accidentally with a ava --update-snapshots command that shouldn’t have happened.

Here is a quick example for the git utility

const test = require('ava')
const gitUtils = require('@netlify/git-utils')

test('Verify git utils API methods exist', async (t) => {
  t.is(typeof gitUtils, 'object')
  t.is(typeof gitUtils.fileMatch, 'function')
  t.is(typeof gitUtils.linesOfCode, 'function')
  t.is(Array.isArray(gitUtils.modifiedFiles), true)
  t.is(Array.isArray(gitUtils.deletedFiles), true)
  t.is(Array.isArray(gitUtils.createdFiles), true)
  t.is(Array.isArray(gitUtils.commits), true)
})

[ehmicky]

I actually added module testing for each utils and for @netlify/config, on top of existing integration tests. So now, each package in the monorepo has its own sets of module tests, but all of the packages together as a whole are also covered with integration tests.

[erquhart]

We’ll revisit testing as needed moving forward, integration tests are sufficient right now.