Working with folders in Node

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The Node.js fs core module provides many handy methods you can use to work with folders.

Check if a folder exists

Use fs.access() to check if the folder exists and Node can access it with its permissions.

Create a new folder

Use fs.mkdir() or fs.mkdirSync() to create a new folder.

const fs = require('fs')

const folderName = '/Users/flavio/test'

try {
  if (!fs.existsSync(dir)){
    fs.mkdirSync(dir)
  }
} catch (err) {
  console.error(err)
}

Read the content of a directory

Use fs.readdir() or fs.readdirSync to read the contents of a directory.

This piece of code reads the content of a folder, both files and subfolders, and returns their relative path:

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

const folderPath = '/Users/flavio'

fs.readdirSync(folderPath)

You can get the full path:

fs.readdirSync(folderPath).map(fileName => {
  return path.join(folderPath, fileName)
}

You can also filter the results to only return the files, and exclude the folders:

const isFile = fileName => {
  return fs.lstatSync(fileName).isFile()
}

fs.readdirSync(folderPath).map(fileName => {
  return path.join(folderPath, fileName)
}).filter(isFile)

Rename a folder

Use fs.rename() or fs.renameSync() to rename folder. The first parameter is the current path, the second the new path:

const fs = require('fs')

fs.rename('/Users/flavio', '/Users/roger', err => {
  if (err) {
    console.error(err)
    return
  }
  //done
})

fs.renameSync() is the synchronous version:

const fs = require('fs')

try {
  fs.renameSync('/Users/flavio', '/Users/roger')
} catch (err) {
  console.error(err)
}

Remove a folder

Use fs.rmdir() or fs.rmdirSync() to remove a folder.

Removing a folder that has content can be more complicated than you need.

In this case I recommend installing the fs-extra module, which is very popular and well maintained, and it’s a drop-in replacement of the fs module, providing more features on top of it.

In this case the remove() method is what you want.

Install it using

npm install fs-extra

and use it like this:

const fs = require('fs-extra')

const folder = '/Users/flavio'

fs.remove(folder, err => {
  console.error(err)
})

It can also be used with promises:

fs.remove(folder).then(() => {
  //done
}).catch(err => {
  console.error(err)
})

or with async/await:

async function removeFolder(folder) {
  try {
    await fs.remove(folder)
    //done
  } catch (err) {
    console.error(err)
  }
}

const folder = '/Users/flavio'
removeFolder(folder)