index.test.js

let fs = require('fs')
let postcss = require('postcss')

let plugin = require('./')

function testEqualResult(input, output, opts) {
  return postcss([plugin(opts)])
    .process(input, { from: undefined })
    .then(result => {
      expect(result.css).toEqual(output)
      expect(result.warnings()).toHaveLength(0)
    })
}

function testSkippedCounter(input) {
  return postcss([plugin()])
    .process(input, { from: undefined })
    .then(result => {
      let etalon = {
        '.skipped-no-overflow': 1,
        '.skipped-with-overflow': 1,
      }

      let targets = Object.keys(etalon)

      let counters = {}

      result.root.nodes.forEach(rule => {
        if (targets.includes(rule.selector)) {
          // get all items with Symbol() in key
          let symbols = Object.getOwnPropertySymbols(rule);

          symbols.forEach(key => {
            if (key.description === 'skippedCounter') {
              counters[rule.selector] = rule[key]
            }
          })
        }
      })

      expect(etalon).toMatchObject(counters)
      expect(result.warnings()).toHaveLength(0)
    })
}

it('if has momentum scroll, do nothing', () => {
  let input = fs.readFileSync('./test/has-momentum.in.css', 'utf8')
  let output = fs.readFileSync('./test/has-momentum.out.css', 'utf8')

  return testEqualResult(input, output)
})

it('custom options (hidden, inherit)', () => {
  let input = fs.readFileSync('./test/custom-opts.in.css', 'utf8')
  let output = fs.readFileSync('./test/custom-opts.out.css', 'utf8')

  return testEqualResult(input, output, ['hidden', 'inherit'])
})

it('if options is not array', () => {
  let input = fs.readFileSync('./test/has-momentum.in.css', 'utf8')
  let output = fs.readFileSync('./test/has-momentum.out.css', 'utf8')

  return testEqualResult(input, output, 'postcss')
})

it('skip if already processed', () => {
  let input = fs.readFileSync('./test/has-momentum.in.css', 'utf8')

  return testSkippedCounter(input)
})