cover.test.js

let { join } = require('path')

let browserslist = require('..')

let CUSTOM_STATS = join(__dirname, 'fixtures', 'stats.json')

let originUsage = browserslist.usage

beforeEach(() => {
  process.env.BROWSERSLIST_STATS = CUSTOM_STATS
  browserslist.usage = {
    'global': {
      'ie 5': 50,
      'ie 11': 10
    },
    'US': {
      'ie 8': 2,
      'ie 9': 4.4
    },
    'alt-us': {
      'ie 8': 25,
      'ie 9': 10
    }
  }
})
afterEach(() => {
  delete process.env.BROWSERSLIST_STATS
  browserslist.usage = originUsage
})

it('adds at least one browser', () => {
  expect(browserslist('cover 1% in my stats')).toEqual(['ie 11'])
})

it('is case insensitive for custom stat', () => {
  expect(browserslist('Cover 1% In My Stats')).toEqual(['ie 11'])
})

it('global coverage', () => {
  expect(browserslist('cover 0.1%')).toEqual(['ie 5'])
})

it('is case insensitive for global coverage', () => {
  expect(browserslist('Cover 0.1%')).toEqual(['ie 5'])
})

it('country coverage', () => {
  expect(browserslist('cover 0.1% in US')).toEqual(['ie 9'])
})

it('country coverage alt', () => {
  expect(browserslist('cover 0.1% in alt-us')).toEqual(['ie 8'])
})

it('is case insensitive for country coverage', () => {
  expect(browserslist('Cover 0.1% in us')).toEqual(['ie 9'])
  expect(browserslist('Cover 0.1% in Alt-US')).toEqual(['ie 8'])
})

it('adds browsers by popularity', () => {
  expect(browserslist('cover 20% in my stats')).toEqual([
    'chrome 37',
    'chrome 36',
    'ie 11',
    'ie 10'
  ])
})

it('does not add zero-popularity', () => {
  let stats = { stats: { ie: { 11: 10, 10: 0 } } }
  expect(browserslist('cover 20% in my stats', stats)).toEqual(['ie 11'])
})

it('throws error on no stats', () => {
  delete process.env.BROWSERSLIST_STATS
  expect(() => {
    browserslist('cover 70% in my stats')
  }).toThrow(/statistics was not provided/)
})