copyDir.js

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

const debug = console.log

const buildDirMap = (dirPath) => {
  const map = {}
  const items = fs.readdirSync(dirPath)
  for (const name of items) {
    map[name] = fs.statSync(path.join(dirPath, name), { throwIfNoEntry: false })
  }
  return map
}

const copyDir = (source, target, level = 1) => {
  // debug('source', source, 'target', target)
  // debug('  '.repeat(level - 1) + path.basename(source))
  const targetStat = fs.statSync(target, { throwIfNoEntry: false })
  const items = fs.readdirSync(source, { withFileTypes: true })
  const checkItems = () => {
    const targetItems = fs.readdirSync(target, { withFileTypes: true })
    for (const targetItem of targetItems) {
      const found = items.find(
        (item) => item.name === targetItem.name && item.isDirectory() === targetItem.isDirectory()
      )
      if (!found) {
        const itemPath = path.join(target, targetItem.name)
        fs.rmSync(itemPath, { recursive: true, force: true })
        debug('deleted', itemPath)
      }
    }
  }
  if (targetStat) {
    if (targetStat.isDirectory()) {
      checkItems()
    } else {
      fs.rmSync(target)
      fs.mkdirSync(target)
    }
  } else {
    fs.mkdirSync(target)
  }
  const sourceMap = buildDirMap(source)
  const targetMap = buildDirMap(target)
  for (const name in sourceMap) {
    const stat = sourceMap[name]
    const targetStat = targetMap[name]
    const sourcePath = path.join(source, name)
    const targetPath = path.join(target, name)
    if (stat.isDirectory()) {
      copyDir(path.join(source, name), path.join(target, name), level + 1)
    } else {
      if (!targetStat || stat.size !== targetStat.size) {
        if (targetStat) fs.rmSync(targetPath)
        fs.copyFileSync(sourcePath, targetPath)
        debug('copied ' + targetPath)
      }
      // debug('  '.repeat(level) + item.name)
    }
  }
}

// copyDir('targets/cep', 'public')