Mini Shell

'use strict'

let npa
const path = require('path')

module.exports = parseArgs
function parseArgs (argv, defaultNpm) {
  argv = argv || process.argv
  if (argv.length > 2 && argv[2][0] !== '-') {
    // fast-path around arg parsing! Don't even need to load yargs here.
    return fastPathArgs(argv, defaultNpm)
  }

  npa = require('npm-package-arg')

  const parser = yargsParser(argv, defaultNpm)

  const opts = parser.getOptions()
  const bools = new Set(opts.boolean)

  let cmdIndex
  let hasDashDash
  for (let i = 2; i < argv.length; i++) {
    const opt = argv[i]
    if (opt === '--') {
      hasDashDash = true
      break
    } else if (opt === '--node-arg' || opt === '-n') {
      argv[i] = `${opt}=${argv[i + 1]}`
      argv.splice(i + 1, 1)
    } else if (opt[0] === '-') {
      if (
        // --no-install needs to be special-cased because we're abusing
        // yargs a bit in order to get the --help text right.
        opt !== '--no-install' &&
        !bools.has(opt.replace(/^--?(no-)?/i, '')) &&
        opt.indexOf('=') === -1
      ) {
        i++
      }
    } else {
      cmdIndex = i
      break
    }
  }
  if (cmdIndex) {
    const parsed = parser.parse(argv.slice(0, cmdIndex))
    const parsedCmd = npa(argv[cmdIndex])
    parsed.command = parsed.package && parsedCmd.type !== 'directory'
      ? argv[cmdIndex]
      : guessCmdName(parsedCmd)
    parsed.isLocal = parsedCmd.type === 'directory'
    parsed.cmdOpts = argv.slice(cmdIndex + 1)
    if (typeof parsed.package === 'string') {
      parsed.package = [parsed.package]
    }
    parsed.packageRequested = !!parsed.package
    parsed.cmdHadVersion = parsed.package || parsedCmd.type === 'directory'
      ? false
      : parsedCmd.name !== parsedCmd.raw
    const pkg = parsed.package || [argv[cmdIndex]]
    parsed.p = parsed.package = pkg.map(p => npa(p).toString())
    return parsed
  } else {
    const parsed = parser.parse(argv)
    if (typeof parsed.package === 'string') {
      parsed.package = [parsed.package]
    }
    // -c *requires* -p, because the -c string should not be touched by npx
    if (parsed.call && parsed.package) {
      parsed.packageRequested = !!parsed.package
      parsed.cmdHadVersion = false
      const pkg = parsed.package
      parsed.p = parsed.package = pkg.map(p => npa(p).toString())
    } else if (parsed.call && !parsed.package) {
      parsed.packageRequested = false
      parsed.cmdHadVersion = false
      parsed.p = parsed.package = []
    } else if (hasDashDash) {
      const splitCmd = parsed._.slice(2)
      const parsedCmd = npa(splitCmd[0])
      parsed.command = parsed.package
        ? splitCmd[0]
        : guessCmdName(parsedCmd)
      parsed.cmdOpts = splitCmd.slice(1)
      parsed.packageRequested = !!parsed.package
      parsed.cmdHadVersion = parsed.package
        ? false
        : parsedCmd.name !== parsedCmd.raw
      const pkg = parsed.package || [splitCmd[0]]
      parsed.p = parsed.package = pkg.map(p => npa(p).toString())
    }
    return parsed
  }
}

function fastPathArgs (argv, defaultNpm) {
  let parsedCmd
  let pkg
  if (argv[2].match(/^[a-z0-9_-]+$/i)) {
    parsedCmd = { registry: true, name: argv[2], raw: argv[2] }
    pkg = [`${argv[2]}@latest`]
  } else {
    npa = require('npm-package-arg')
    parsedCmd = npa(argv[2])
    if (parsedCmd.type === 'directory') {
      pkg = []
    } else {
      pkg = [parsedCmd.toString()]
    }
  }
  return {
    command: guessCmdName(parsedCmd),
    cmdOpts: argv.slice(3),
    packageRequested: false,
    isLocal: parsedCmd.type === 'directory',
    cmdHadVersion: (
      parsedCmd.name !== parsedCmd.raw &&
      parsedCmd.type !== 'directory'
    ),
    package: pkg,
    p: pkg,
    shell: false,
    noYargs: true,
    npm: defaultNpm || 'npm'
  }
}

parseArgs.showHelp = () => require('yargs').showHelp()

module.exports._guessCmdName = guessCmdName
function guessCmdName (spec) {
  if (typeof spec === 'string') {
    if (!npa) { npa = require('npm-package-arg') }
    spec = npa(spec)
  }
  if (spec.scope) {
    return spec.name.slice(spec.scope.length + 1)
  } else if (spec.registry) {
    return spec.name
  } else if (spec.hosted && spec.hosted.project) {
    return spec.hosted.project
  } else if (spec.type === 'git') {
    const match = spec.fetchSpec.match(/([a-z0-9-]+)(?:\.git)?$/i)
    return match[1]
  } else if (spec.type === 'directory') {
    return spec.raw
  } else if (spec.type === 'file' || spec.type === 'remote') {
    let ext = path.extname(spec.fetchSpec)
    if (ext === '.gz') {
      ext = path.extname(path.basename(spec.fetchSpec, ext)) + ext
    }
    return path.basename(spec.fetchSpec, ext).replace(/-\d+\.\d+\.\d+(?:-[a-z0-9.\-+]+)?$/i, '')
  }

  console.error(Y()`Unable to guess a binary name from ${spec.raw}. Please use --package.`)
  return null
}

function yargsParser (argv, defaultNpm) {
  const usage = `
  npx [${Y()`options`}] <${Y()`command`}>[@${Y()`version`}] [${Y()`command-arg`}]...

  npx [${Y()`options`}] [-p|--package <${Y()`package`}>]... <${Y()`command`}> [${Y()`command-arg`}]...

  npx [${Y()`options`}] -c '<${Y()`command-string`}>'

  npx --shell-auto-fallback [${Y()`shell`}]
  `

  return require('yargs')
    .usage(Y()`Execute binaries from npm packages.\n${usage}`)
    .option('package', {
      alias: 'p',
      type: 'string',
      describe: Y()`Package to be installed.`
    })
    .option('cache', {
      type: 'string',
      describe: Y()`Location of the npm cache.`
    })
    .option('always-spawn', {
      describe: Y()`Always spawn a child process to execute the command.`,
      type: 'boolean'
    })
    .option('no-install', {
      type: 'boolean',
      describe: Y()`Skip installation if a package is missing.`
    })
    .option('userconfig', {
      type: 'string',
      describe: Y()`Path to user npmrc.`
    })
    .option('call', {
      alias: 'c',
      type: 'string',
      describe: Y()`Execute string as if inside \`npm run-script\`.`
    })
    .option('shell', {
      alias: 's',
      type: 'string',
      describe: Y()`Shell to execute the command with, if any.`,
      default: false
    })
    .option('shell-auto-fallback', {
      choices: ['', 'bash', 'fish', 'zsh'],
      describe: Y()`Generate shell code to use npx as the "command not found" fallback.`,
      requireArg: false,
      type: 'string'
    })
    .option('ignore-existing', {
      describe: Y()`Ignores existing binaries in $PATH, or in the local project. This forces npx to do a temporary install and use the latest version.`,
      type: 'boolean'
    })
    .option('quiet', {
      alias: 'q',
      describe: Y()`Suppress output from npx itself. Subcommands will not be affected.`,
      type: 'boolean'
    })
    .option('npm', {
      describe: Y()`npm binary to use for internal operations.`,
      type: 'string',
      default: defaultNpm || 'npm'
    })
    .option('node-arg', {
      alias: 'n',
      type: 'string',
      describe: Y()`Extra node argument when calling a node binary.`
    })
    .version()
    .alias('version', 'v')
    .help()
    .alias('help', 'h')
    .epilogue(Y()`For the full documentation, see the manual page for npx(1).`)
}

var _y
function Y () {
  if (!_y) { _y = require('./y.js') }
  return _y
}