command-line-util/index.js

Command-line utility package provides bush command myls

#!/usr/bin/env node
const fs = require('fs')

const directoryPath = process.cwd()

const regex = /^\..*/

const FILTER_FLAGS = ['-hf', '-vf']
const SORT_FLAGS = ['-t']
const RENDER_FLAGS = ['-l']

const SUPPORTED_FLAGS = [...FILTER_FLAGS, ...SORT_FLAGS, ...RENDER_FLAGS]

function isHidden (filename) {
  return regex.test(filename)
};

function sortBySupportedValues (inputValues, supportedValues) {
  return inputValues.sort((a, b) => supportedValues.indexOf(a) - supportedValues.indexOf(b))
}

function hasOnlyValidOptions (inputValues, supportedValues) {
  return inputValues.every(item => supportedValues.includes(item))
}

function getFilesStats (filenames, directory) {
  return filenames.map(filename => ({
    stat: fs.statSync(`${directory}/${filename}`),
    filename
  }))
}

function print (data = []) {
  data.forEach(item => console.log(item))
}

function handleFilesByFlag (filesnames, flag) {
  switch (flag) {
    case '-hf':
      return filesnames.filter(isHidden)
    case '-vf':
      return filesnames.filter(file => !isHidden(file))
    case '-t':
      return getFilesStats(filesnames, directoryPath)
        .sort((a, b) => a.stat.ctime < b.stat.ctime)
        .map(item => item.filename)
    case '-l':
      return getFilesStats(filesnames, directoryPath)
        .map(({ filename, stat }) => `Filename: ${filename}, size in bytes: ${stat.size}, last modified date: ${stat.mtime}`)
    default:
      return filesnames
  }
}

function handleFiles (files, flags) {
  return flags.reduce((accum, flag) => {
    return handleFilesByFlag(accum, flag)
  }, files)
}

function executeCommand () {
  const [,, ...args] = process.argv

  if (args.length > 0 && !hasOnlyValidOptions(args, SUPPORTED_FLAGS)) {
    throw new Error(`Provided arguments for myls command are not supported\nPlease, use these ${SUPPORTED_FLAGS.join(', ')}.`)
  }

  try {
    const files = fs.readdirSync(directoryPath)
    const sortedArgs = sortBySupportedValues(args, SUPPORTED_FLAGS)
    return args.length === 0 ? files : handleFiles(files, sortedArgs)
  } catch (error) {
    if (error.code === 'ENOENT') {
      console.log('No such file or directory!')
    } else {
      throw error
    }
  }
}

const filesToShow = executeCommand()
print(filesToShow)

module.exports = executeCommand