test/test/common/tmpdir.js

Node.js 18's node:test, as an npm package

// https://github.com/nodejs/node/blob/1aab13cad9c800f4121c1d35b554b78c1b17bdbd/test/common/tmpdir.js
'use strict'

const fs = require('fs')
const path = require('path')
const { isMainThread } = require('worker_threads')

function rmSync (pathname) {
  fs.rmSync(pathname, { maxRetries: 3, recursive: true, force: true })
}

const testRoot = process.env.NODE_TEST_DIR
  ? fs.realpathSync(process.env.NODE_TEST_DIR)
  : path.resolve(__dirname, '..')

// Using a `.` prefixed name, which is the convention for "hidden" on POSIX,
// gets tools to ignore it by default or by simple rules, especially eslint.
const tmpdirName = '.tmp.' +
  (process.env.TEST_SERIAL_ID || process.env.TEST_THREAD_ID || '0')
const tmpPath = path.join(testRoot, tmpdirName)

let firstRefresh = true
function refresh () {
  rmSync(this.path)
  fs.mkdirSync(this.path)

  if (firstRefresh) {
    firstRefresh = false
    // Clean only when a test uses refresh. This allows for child processes to
    // use the tmpdir and only the parent will clean on exit.
    process.on('exit', onexit)
  }
}

function onexit () {
  // Change directory to avoid possible EBUSY
  if (isMainThread) { process.chdir(testRoot) }

  try {
    rmSync(tmpPath)
  } catch (e) {
    console.error('Can\'t clean tmpdir:', tmpPath)

    const files = fs.readdirSync(tmpPath)
    console.error('Files blocking:', files)

    if (files.some((f) => f.startsWith('.nfs'))) {
      // Warn about NFS "silly rename"
      console.error('Note: ".nfs*" might be files that were open and ' +
                    'unlinked but not closed.')
      console.error('See http://nfs.sourceforge.net/#faq_d2 for details.')
    }

    console.error()
    throw e
  }
}

module.exports = {
  path: tmpPath,
  refresh
}