fs-extra

What is fs-extra?

The fs-extra package is a file system module for Node.js that extends the built-in 'fs' module. It provides additional methods and simplifies certain file operations, such as copying, moving, deleting files and directories, and more. It also adds promise support to the fs methods.

What are fs-extra's main functionalities?

Copying files and directories

This feature allows you to copy files and directories from one location to another. The method returns a promise that resolves when the operation is complete.

const fs = require('fs-extra');

fs.copy('/path/to/source', '/path/to/dest')
  .then(() => console.log('Copy successful!'))
  .catch(err => console.error(err));

Moving files and directories

This feature enables you to move files and directories to a new location. Like copy, it returns a promise and provides a simple API for a task that would otherwise require multiple steps.

const fs = require('fs-extra');

fs.move('/path/to/source', '/path/to/dest')
  .then(() => console.log('Move successful!'))
  .catch(err => console.error(err));

Removing files and directories

This feature is used to delete files and directories. It is a safer and more powerful alternative to the standard 'fs.unlink' and 'fs.rmdir' methods, as it can remove non-empty directories.

const fs = require('fs-extra');

fs.remove('/path/to/dir')
  .then(() => console.log('Removal successful!'))
  .catch(err => console.error(err));

Reading and writing JSON files

This feature simplifies the process of reading and writing JSON files. It automatically handles stringifying objects when writing and parsing JSON data when reading.

const fs = require('fs-extra');

const myData = { name: 'fs-extra' };
fs.writeJson('/path/to/file.json', myData)
  .then(() => console.log('Write successful!'))
  .catch(err => console.error(err));

Ensuring a file or directory exists

This feature checks if a file or directory exists, and if it does not, it is created. This is useful for making sure that a given file or directory is present before performing operations on it.

const fs = require('fs-extra');

fs.ensureFile('/path/to/file.txt')
  .then(() => console.log('File exists!'))
  .catch(err => console.error(err));

Other packages similar to fs-extra

rimraf

Rimraf is a Node.js package that provides a simple way to delete files and directories with a UNIX command 'rm -rf' like functionality. It is less feature-rich compared to fs-extra, which provides a broader set of file system operations.

mkdirp

Mkdirp is a package that allows you to create a new directory and its parent directories if they do not exist (similar to the 'mkdir -p' command in UNIX). It is more focused than fs-extra, which includes this functionality as part of a larger suite of file system tools.

graceful-fs

Graceful-fs is a drop-in replacement for the fs module that makes file system operations more robust by queuing them and retrying on certain types of errors. It does not add new methods like fs-extra but improves the reliability of existing ones.

node-fs-extra

Node-fs-extra is a fork of fs-extra that aims to provide the same functionality. However, fs-extra is more commonly used and actively maintained, making it the preferred choice for most developers.

README

Node.js: fs-extra

This module adds a few extra file system methods that aren't included in the native fs module. It is a drop in replacement for fs.

Why?

I got tired of including mkdirp and rimraf in most of my projects.

Installation

npm install fs-extra

Usage

var fs = require('fs-extra');

Naming

I put a lot of thought into the naming of these function. Inspired by @coolaj86's request. So he deserves much of the credit for raising the issue. See discussion(s) here:

• https://github.com/jprichardson/node-fs-extra/issues/2
• https://github.com/flatiron/utile/issues/11
• https://github.com/ryanmcgrath/wrench-js/issues/29
• https://github.com/substack/node-mkdirp/issues/17

First, I believe that in as many cases as possible, the Node.js naming schemes should be chosen. However, there are problems with the Node.js own naming schemes.

For example, fs.readFile() and fs.readdir(): the F is capitalized in File and the d is not capitalized in dir. Perhaps a bit pedantic, but they should still be consistent. Also, Node.js has chosen a lot of POSIX naming schemes, which I believe is great. See: fs.mkdir(), fs.rmdir(), fs.chown(), etc.

We have a dilemma though. How do you consistently name methods perform the following POSIX commands: cp, cp -r, mkdir -p, and rm -rf?

My perspective: when in doubt, err on the side of simplicity. Consider that for a moment. A directory is just a hierarchical grouping of directories and files. So when you want to copy it or remove it, in most cases you'll want to copy or remove all of its contents. When you want to create a directory, if the directory that it's suppose to be contained in does not exist, then in most cases you'll want to create that too.

So, if you want to remove a file or a directory regardless of whether it has contents, just call fs.remove(path) or its alias fs.delete(path). If you want to copy a file or a directory whether it has contents, just call fs.copy(source, destination). If you want to create a directory regardless of whether its parent directories exist, just call fs.mkdir(path). (Note: you can still use the native Node.js fs.mkdir() method by requiring fs and calling mkdir on that object)

Compromise

If you feel that this module should add functionality, please let me know. If you don't like the naming scheme, let me know that as well. I'm willing to work with the community so that we can develop a logical grouping of file system functions that aren't found Node.js.

Methods

NOTE: You can still use the native Node.js methods. They are copied over to fs-extra.

copy()

Copy a file or directory. The directory can have contents. Like cp -r. There isn't a synchronous version implemented yet.

Examples:

var fs = require('fs-extra');

fs.copy('/tmp/myfile', '/tmp/mynewfile', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
}); //copies file

fs.copy('/tmp/mydir', '/tmp/mynewdir'function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
}); //copies directory, even if it has subdirectories or files

remove()

Removes a file or directory. The directory can have contents. Like rm -rf.

Alias: delete().

Examples:

var fs = require('fs-extra');

fs.remove('/tmp/myfile', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
});

fs.removeSync('/home/jprichardson'); //I just deleted my entire HOME directory. 

mkdir()

Creates a directory. If the parent hierarchy doesn't exist, it's created. Like mkdir -p.

Examples:

var fs = require('fs');
var fse = require('fs-extra');

fse.mkdir('/tmp/some/long/path/that/prob/doesnt/exist', function(err){
  if (err) {
    console.error(err);
  }
  else {
    console.log("success!")
  }
});

fse.mkdirSync('/tmp/another/path');

//now use Node.js native mkdir()

fs.mkdir('/tmp/node/cant/do/this', function(err){
  console.log('this wasnt successful');
});

fs.readJSONFile()

Reads a JSON file and then parses it into an object.

Example:

var fs = require('fs-extra');

fs.readJSONFile('./package.json', function(err, packageObj) {
  console.log(packageObj.version); //0.1.3
});

exists() / existsSync()

These methods are actually from path. But in Node v0.8 they are moved from path to fs. So you might as well start future proofing your code now.

License

Licensed under MIT

Copyright (c) 2011-2012 JP Richardson