A script to convert .js to .jsx when they contains JSX tags

rename-js-to-jsx.js

// node ./rename-js-to-jsx.js ./my/folder

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

// Options
const src = process.argv[2] ?? './'
const pattern = process.argv[3] ? new RegExp(`${process.argv[3]}$`) : /.js$/
const newExtension = process.argv[4] ?? '.jsx'

console.log(`Path = ${src} ; pattern = ${pattern} ; newExtension = ${newExtension}`)

const getAllFiles = (dirPath, pattern, files = []) => {
  const filesInDirectory = fs.readdirSync(dirPath)

  return filesInDirectory.reduce((foundFiles, file) => {
    if (fs.statSync(`${dirPath}/${file}`).isDirectory()) {
      return getAllFiles(`${dirPath}/${file}`, pattern, foundFiles)
    } else {
      if (!matchPattern(file, pattern)) {
        return foundFiles
      }

      return [
        ...foundFiles,
        path.join(__dirname, dirPath, '/', file),
      ]
    }
  }, files)
}

const matchPattern = (filename, pattern) => filename.match(pattern)

const readFile = (path) => fs.readFileSync(path).toString('utf-8')

const renameFile = (path, extension) => {
  try {
    fs.renameSync(path, path.replace(pattern, extension))
    console.log(`${path} [RENAMED]`)
    return true
  } catch (error) {
    console.log(`${path} [KO]`, error)
    return false
  }
}

// <> </> <tag /> <tag></tag>
const containsJSX = (content) => /(<\/|\/>)/.test(content)

// Run
console.log('Search files...')

const files = getAllFiles(src, pattern)
  .map((file) => ({filename: file, content: readFile(file)}))
  .filter((file) => containsJSX(file.content))
  .map((file) => file.filename)

console.log('Found files', files.length)

console.log('Renaming...')

const successFiles = files
  .map((file) => renameFile(file, newExtension))
  .filter(Boolean)

console.log(`Rename ${successFiles.length}/${files.length} with success.`)

if (successFiles.length !== files.length) {
  console.log('Execution encountered some errors.')
  process.exit(1)
}

How does it work, would you please explain!

This script will scans the files in the given directory and renames all .js files that contains JSX tags to .jsx files.

Signature:

node ./rename-js-to-jsx.js [directory] [oldExtension] [newExtension]

By default:

• directory is the current directory
• oldExtension is .js
• newExtension is .jsx

You can customize which files to scan with the second argument.

For example to rename all .ts that contains JSX tags to .jsx (not a real example but still):

node ./rename-js-to-jsx.js ./src .ts

You can also customize which new extension you want for your JSX files with the third argument (more sense for this one):

node ./rename-js-to-jsx.js ./src .ts .tsx

I think the period in the pattern on line 8 should be escaped, otherwise treated as any character in regexp:

const pattern = process.argv[3] ? new RegExp(`${process.argv[3]}$`) : /\.js$/