Node.js: extra methods for the fs object like copy(), remove(), mkdirs()
Node.js: extra methods for the fs object like copy(), remove(), mkdirs()
fs-extra adds file system methods that aren't included in the native fs module and adds promise support to the fs methods. It also uses graceful-fs to prevent EMFILE errors. It should be a drop in replacement for fs.
Why?I got tired of including mkdirp, rimraf, and ncp in most of my projects.
npm install fs-extrafs-extra is a drop in replacement for native fs. All methods in fs are attached to fs-extra. All fs methods return promises if the callback isn't passed.
You don't ever need to include the original fs module again:
const fs = require('fs') // this is no longer necessaryyou can now do this:
const fs = require('fs-extra')or if you prefer to make it clear that you're using fs-extra and not fs, you may want
to name your fs variable fse like so:
const fse = require('fs-extra')you can also keep both, but it's redundant:
const fs = require('fs')
const fse = require('fs-extra')NOTE: The deprecated constants fs.F_OK, fs.R_OK, fs.W_OK, & fs.X_OK are not exported on Node.js v24.0.0+; please use their fs.constants equivalents.
There is also an fs-extra/esm import, that supports both default and named exports. However, note that fs methods are not included in fs-extra/esm; you still need to import fs and/or fs/promises separately:
import { readFileSync } from 'fs'
import { readFile } from 'fs/promises'
import { outputFile, outputFileSync } from 'fs-extra/esm'Default exports are supported:
import fs from 'fs'
import fse from 'fs-extra/esm'
// fse.readFileSync is not a function; must use fs.readFileSyncbut you probably want to just use regular fs-extra instead of fs-extra/esm for default exports:
import fs from 'fs-extra'
// both fs and fs-extra methods are definedMost methods are async by default. All async methods will return a promise if the callback isn't passed.
Sync methods on the other hand will throw if an error occurs.
Also Async/Await will throw an error if one occurs.
Example:
…NOTE: You can still use the native Node.js methods. They are promisified and copied over to fs-extra. See notes on fs.read(), fs.write(), & fs.writev()
walk() and walkSync()?They were removed from fs-extra in v2.0.0. If you need the functionality, walk and walkSync are available as separate packages, klaw and klaw-sync.
fse-cli allows you to run fs-extra from a console or from npm scripts.
If you like TypeScript, you can use fs-extra with it: https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/fs-extra
If you want to watch for changes to files or directories, then you should use chokidar.
fs-filesystem allows you to read the state of the filesystem of the host on which it is run. It returns information about both the devices and the partitions (volumes) of the system.
Wanna hack on fs-extra? Great! Your help is needed! fs-extra is one of the most depended upon Node.js packages. This project
uses JavaScript Standard Style - if the name or style choices bother you,
you're gonna have to get over it :) If standard is good enough for npm, it's good enough for fs-extra.
What's needed?
Note: If you make any big changes, you should definitely file an issue for discussion first.
fs-extra contains hundreds of tests.
npm run lint: runs the linter (standard)npm run unit: runs the unit testsnpm run unit-esm: runs tests for fs-extra/esm exportsnpm test: runs the linter and all testsWhen running unit tests, set the environment variable CROSS_DEVICE_PATH to the absolute path of an empty directory on another device (like a thumb drive) to enable cross-device move tests.
If you run the tests on the Windows and receive a lot of symbolic link EPERM permission errors, it's
because on Windows you need elevated privilege to create symbolic links. You can add this to your Windows's
account by following the instructions here: http://superuser.com/questions/104845/permission-to-make-symbolic-links-in-windows-7
However, I didn't have much luck doing this.
Since I develop on Mac OS X, I use VMWare Fusion for Windows testing. I create a shared folder that I map to a drive on Windows.
I open the Node.js command prompt and run as Administrator. I then map the network drive running the following command:
net use z: "\\vmware-host\Shared Folders"I can then navigate to my fs-extra directory and run the tests.
I put a lot of thought into the naming of these functions. Inspired by @coolaj86's request. So he deserves much of the credit for raising the issue. See discussion(s) here:
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 that perform the following POSIX commands: cp, cp -r, mkdir -p, and rm -rf?
My perspective: when in doubt, err on the side of simplicity. A directory is just a hierarchical grouping of directories and files. Consider that for a moment. 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). 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.mkdirs(path) or fs.mkdirp(path).
fs-extra wouldn't be possible without using the modules from the following authors:
Licensed under MIT
Copyright (c) 2011-2024 JP Richardson
Update devDependencies
Feature request: isEmptyDir()
Question about copy logic
fs.cp coming to Node.js core
Heads up: fs.createWriteStream will cause a memory leak
Inconsistency between readJson and readJsonSync when file does not exist
Problems when dealing with invalidly-encoded filenames
Error "Source and destination must not be the same" in move-sync on unicode normalization difference
feature request: fs.softDelete or the like?
Unify test directories