memfs

In-memory file-system with Node's fs API.

Node's fs API implemented, see old API Status, missing list, missing opendir
Stores files in memory, in Buffers
Throws sameish* errors as Node.js
Has concept of i-nodes
Implements hard links
Implements soft links (aka symlinks, symbolic links)
Permissions may* be implemented in the future
Can be used in browser, see memfs-webpack

shell npm install --save memfs

Usage

```js import { fs } from 'memfs';

fs.writeFileSync('/hello.txt', 'World!'); fs.readFileSync('/hello.txt', 'utf8'); // World! ```

Create a file system from a plain JSON:

```js import { fs, vol } from 'memfs';

const json = { './README.md': '1', './src/index.js': '2', './node_modules/debug/index.js': '3', }; vol.fromJSON(json, '/app');

fs.readFileSync('/app/README.md', 'utf8'); // 1 vol.readFileSync('/app/src/index.js', 'utf8'); // 2 ```

Export to JSON:

js vol.writeFileSync('/script.sh', 'sudo rm -rf *'); vol.toJSON(); // {"/script.sh": "sudo rm -rf *"}

Use it for testing:

js vol.writeFileSync('/foo', 'bar'); expect(vol.toJSON()).toEqual({ '/foo': 'bar' });

Create as many filesystem volumes as you need:

```js import { Volume } from 'memfs';

const vol = Volume.fromJSON({ '/foo': 'bar' }); vol.readFileSync('/foo'); // bar

const vol2 = Volume.fromJSON({ '/foo': 'bar 2' }); vol2.readFileSync('/foo'); // bar 2 ```

Use memfs together with unionfs to create one filesystem from your in-memory volumes and the real disk filesystem:

```js import * as fs from 'fs'; import { ufs } from 'unionfs';

ufs.use(fs).use(vol);

ufs.readFileSync('/foo'); // bar ```

Use fs-monkey to monkey-patch Node's require function:

```js import { patchRequire } from 'fs-monkey';

vol.writeFileSync('/index.js', 'console.log("hi world")'); patchRequire(vol); require('/index'); // hi world ```

Unlicense - public domain.