lint.js

const fs = require('fs')
const remark = require('remark')
const report = require('vfile-reporter')
const path = require('path')

module.exports = {
  getLangFromFilename,
  lint
}

const excludes = [
  'README.md',
  'CONTRIBUTING.md',
  'CODE_OF_CONDUCT.md',
  'SUMMARY.md'
]

const langsToAlphabetize = [
  'ar',
  'az',
  'bg',
  'bl',
  'cs',
  'de',
  'dk',
  'en-US',
  'en',
  'es',
  'et',
  'fa-IR',
  'fi',
  'fr',
  'gr',
  'hi',
  'hu',
  'id',
  'it',
  'ja',
  'kk',
  'ko',
  'my',
  'nl',
  'no',
  'pl',
  'pt-BR',
  'pt-PT',
  'ro',
  'ru',
  'se',
  'sk',
  'ta',
  'th',
  'tr',
  'ua',
  'vi',
  'zh'
]

function getLangFromFilename (filename) {
  const dash = filename.lastIndexOf('-')
  const dot = filename.lastIndexOf('.')
  let lang = filename.slice(dash + 1, dot).replace(/_/, '-')
  if (!langsToAlphabetize.includes(lang)) {
    if (/^[a-z]{2}$/.test(lang) || /^[a-z]{2}-[A-Z]{2}$/.test(lang)) {
      return ''
    }
    lang = 'en-US'
  }
  return lang
}

function getFilesFromDir (dir) {
  return fs.readdirSync(dir).filter(file => path.extname(file) === '.md' && excludes.indexOf(file) === -1).map(file => path.join(dir, file))
}

const commonPreset = {
  plugins: [
    [require('remark-lint')],
    [require('remark-lint-final-newline'), true],
    [require('remark-lint-heading-style'), 'atx'],
    [require('remark-lint-no-duplicate-headings'), true],
    [require('remark-lint-no-emphasis-as-heading'), true],
    [require('remark-lint-no-heading-content-indent'), true],
    [require('remark-lint-no-heading-indent'), true],
    [require('remark-lint-no-heading-punctuation'), true],
    [require('remark-lint-no-literal-urls'), true],
    [require('remark-lint-no-tabs'), true],
    [require('remark-lint-strong-marker'), 'consistent'],
    [require('remark-lint-unordered-list-marker-style'), '*'],
    [require('remark-lint-blank-lines-1-0-2')],
    [require('remark-lint-books-links')],
    [require('remark-lint-no-empty-sections')],
    [require('remark-lint-no-url-trailing-slash')]
  ]
}

function lint (directory) {
  let failed = false
  const filenames = getFilesFromDir(path.resolve(directory))
  filenames.forEach((filename) => {
    const doc = fs.readFileSync(filename)
    const lang = getLangFromFilename(filename)
    const processor = remark().use(commonPreset)
    if (lang) {
      processor.use(require('remark-lint-alphabetize-lists'), lang)
    }

    processor.process(doc, (err, file) => {
      if (report(err || file) !== 'no issues found') {
        failed = true
        console.log(filename)
        console.error(report(err || file))
      }
    })
  })

  return failed
}