fake-fs

Fake file system for testing

fake-fs

Fake node.js file system for testing. Supports stat, exists, readdir, readFile, writeFile, appendFile, mkdir, rmdir, unlink, rename and their sync counterparts.

var Fs = require('fake-fs')
var fs = new Fs

Define a dir

fs.dir('a/b/c')
fs.existsSync('a/b/c').should.be.true
fs.existsSync('a').should.be.true // note that it works like mkdir -p 
fs.existsSync('.').should.be.true // in fact you defined an item at absolute path 
fs.existsSync(process.cwd()).should.be.true

Dir with some meta

fs.dir('bin', {
  mtime: 100, // by default it will be set to (new Date) 
  atime: 300,
  ctime: 50
})
fs.statSync('bin').should.have.property('mtime').equal(100)

Define an empty file

fs.file('foo/bar.txt')
fs.readFileSync('foo/bar.txt', 'utf8').should.equal('')
fs.statSync('foo').isDirectory().should.be.true // foo automatically created 

Define a file with content

fs.file('hello.txt', 'Hello world') // utf8 assumed 
fs.file('base64.txt', 'TWFu', 'base64')
fs.file('bin', new Buffer([10, 20]))

Define a file with arbitrary attributes

fs.file('file', {
  content: 'asdf',
  mtime: new Date,
  hello: 'hello'
})
 
fs.readFileSync('file', 'utf8').should.equal('asdf')
fs.statSync('file').should.have.property('hello').equal('hello')

Sometimes you may want to define several items at one location. The .at(path) returns a proxy which prefixes everything you defined with path.

fs.at('public/assets')
  .file('style.css')
  .file('icons.png')
fs.existsSync('public/assets/icons.png').should.be.true

It also has convenience methods for patching-unpatching of global fs object.

fs.patch()
fs.dir('foo')
require('fs').existsSync('foo').should.be.true
fs.unpatch()
require('fs').existsSync('foo').should.be.false

Methods of new fs object are not bound to the instance. That means

var fs = new Fs
var exists = fs.existsSync
exists('/foo/bar')

doesn't work. You can use .bind() if that's a problem.

var fs = new Fs().bind()
var exists = fs.existsSync
exists('/foo/bar') // now everything is ok 

Via npm

npm install fake-fs

To run tests use npm test command.

npm install
npm test

(The MIT License)

Copyright (c) 2012 Eldar Gabdullin eldargab@gmail.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.