generate-sidebar.js

const fs = require('fs')
const path = require('path')
const nanoMd = require('nano-markdown')
const watch = require('watch')

const PATH_TO_IGNORE = ['_sidebar', 'node_modules', '.git', '.history', '.vscode']
const TOP_LEVEL = __dirname

/**
 *
 * File Object
 *
 */
function File (filePath, level = 0) {
  this.level = level
  this.filePath = filePath
  this.infos = path.parse(this.filePath)
  this.datas = {
    level: this.level
  }

  this.parse = () => {
    this.setRoute()
    this.setName()

    if (this.isDirectory() && this.hasOtherThanIndexChildren()) {
      this.datas.children = parseDirectory(this.filePath, this.level + 1)
    }
  }

  this.setRoute = () => {
    if (this.isDirectory() && !this.hasIndexChildren()) return

    this.route = path.relative(TOP_LEVEL, this.filePath)
    this.route = this.route.replace(/README\.md/i, '')
    this.route = this.route.replace(/\.md/i, '/')

    // home fix
    if (this.route.length === 0) this.route = '/'

    // Ensure all routes end with /
    if (this.isDirectory() && !this.route.endsWith('/'))
      this.route += '/'

    if (!this.isDirectory() && !this.isReadmeFile() && this.route.endsWith('/'))
      this.route = this.route.slice(0, -1)

    this.datas.route = this.route
  }

  this.setNameFromFileName = () => {
    if (this.isHome()) {
      this.name = 'Accueil'
    } else {
      this.name = this.infos.name
      this.name = this.name.replace('.md', '')
      this.name = this.name.charAt(0).toUpperCase() + this.name.slice(1)
    }
  }

  this.setNameFromH1 = () => {
    let fileToRead = null

    if (!this.isDirectory()) fileToRead = this.filePath

    if (this.isDirectory() && this.hasIndexChildren()) fileToRead = this.getIndexChildren()

    if (!fileToRead) return

    let fileContent = fs.readFileSync(fileToRead, 'utf8')
    let fileContentMd = nanoMd(fileContent)
    let regex = new RegExp(/<h1>(.*?)<\/h1>/)
    let firstH1 = regex.exec(fileContentMd)

    if (firstH1) this.name = firstH1[1]
  }

  this.setName = () => {
    this.setNameFromH1()

    if (!this.name) this.setNameFromFileName()

    this.datas.name = this.name
  }

  this.isDirectory = () => {
    return fs.statSync(this.filePath).isDirectory()
  }

  this.isMdFile = () => {
    return this.infos.ext === '.md'
  }

  this.isReadmeFile = () => {
    return /readme/i.test(this.infos.name)
  }

  this.isIgnored = () => {
    return (PATH_TO_IGNORE.indexOf(this.infos.name) > -1) || (!this.isMdFile() && !this.isDirectory()) || (this.level > 0 && this.isReadmeFile()) || (this.isDirectory() && !this.hasChildren())
  }

  this.isHome = () => {
    return this.route === '/'
  }

  this.hasIndexChildren = () => {
    return fs.readdirSync(this.filePath).some(i => /readme\.md/i.test(i))
  }

  this.getIndexChildren = () => {
    let index = fs.readdirSync(this.filePath).find(i => /readme\.md/i.test(i))
    if (index) index = path.resolve(this.filePath, index)

    return index
  }

  this.hasOtherThanIndexChildren = () => {
    return fs.readdirSync(this.filePath).some(i => !/readme\.md/i.test(i))
  }

  this.hasChildren = () => {
    return fs.readdirSync(this.filePath).length > 0
  }

  this.getDatas = () => {
    return this.datas
  }
}

const parseDirectory = (dirPath, level = 0) => {
  return fs.readdirSync(dirPath).reduce((acc, fileName) => {
    const filePath = path.join(dirPath, fileName)
    const file = new File(filePath, level)

    if (file.isIgnored()) return acc

    file.parse()

    acc.push(file.getDatas())

    return acc
  }, [])
}

// Create text to insert
const createText = (a, txt = '') => {
  return a.reduce((acc, curr) => {
    let text = (curr.route) ? `- [${curr.name}](${curr.route})` : `- ${curr.name}`

    acc += '  '.repeat(curr.level) + text + '\n'

    if (curr.children) {
      acc += createText(curr.children)
    }

    return acc
  }, txt)
}

const execute = () => {
  let directoryStructure = parseDirectory(path.join(__dirname))

  let text = createText(directoryStructure)

  fs.writeFileSync(path.join(__dirname, '_sidebar.md'), text)
}

watch.watchTree(__dirname, {
  filter: (file) => {
    return (fs.statSync(file).isDirectory() && PATH_TO_IGNORE.indexOf(file) === -1) || (path.extname(file) === '.md' && path.basename(file, '.md') !== '_sidebar')
  }
}, (f, curr, prev) => {
  if (typeof f == 'object' && prev === null && curr === null) {

  } else if (prev === null) {
    // file creation
    execute()
  } else if (curr.nlink === 0) {
    // file deletion
    execute()
  } else {
    // file change
    execute()
  }
})

execute()