traverse-folders/src/index.js

Traverse nested folders and process each of the discovered files.

const fs = require('fs')
const path = require('path')

const { ERROR_BUSY, ERROR_NOT_DIR } = require('./constants')
const makeFileFilter = require('./utils/makeFileFilter')

const DEFAULT_OPTIONS = {
  ignore: 'index.js',
  suffix: '.js'
}

const traverse = (base, processor, options = {}) => {
  const { ignore, suffix } = { ...DEFAULT_OPTIONS, ...options }

  const isJsFile = makeFileFilter(ignore, suffix)

  const traversePath = folder => {
    const findFile = file => {
      const folderOrFile = path.join(folder, file)
      try {
        traversePath(folderOrFile)
      } catch (err) {
        /* istanbul ignore if */
        if (err.code !== ERROR_NOT_DIR && /* istanbul ignore next */ err.code !== ERROR_BUSY)
          throw err
        if (isJsFile(folderOrFile) && typeof processor === 'function') processor(folderOrFile)
      }
    }

    fs.readdirSync(folder).forEach(findFile)
  }

  traversePath(base)
}

module.exports = traverse