Working with folders in Node.js

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() (and its promise-based fsPromises.access() counterpart) to check if the folder exists and Node.js can access it with its permissions.

Create a new folder

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

const fs = require('fs');

const folderName = '/Users/joe/test';

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

Read the content of a directory

Use fs.readdir() or fs.readdirSync() or fsPromises.readdir() 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 folderPath = '/Users/joe';

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

const fs = require('fs');

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

fs.renameSync() is the synchronous version:

const fs = require('fs');

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

fsPromises.rename() is the promise-based version:

const fs = require('fs/promises');

async function example() {
  try {
    await fs.rename('/Users/joe', '/Users/roger');
  } catch (err) {
    console.log(err);
  }
}
example();

Remove a folder

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

const fs = require('fs');

fs.rmdir(dir, err => {
  if (err) {
    throw err;
  }

  console.log(`${dir} is deleted!`);
});

To remove a folder that has contents use fs.rm() with the option { recursive: true } to recursively remove the contents.

{ recursive: true, force: true } makes it so that exceptions will be ignored if the folder does not exist.

const fs = require('fs');

fs.rm(dir, { recursive: true, force: true }, err => {
  if (err) {
    throw err;
  }

  console.log(`${dir} is deleted!`);
});