mem-fs

mem-fs

Simple in-memory vinyl file store.

Usage

Loading a file

You access a file using store#get() method. If the file is in memory, it will be used. Otherwise, we'll load the file from the file-system.

import { create } from 'mem-fs';

const store = create();
store.get('/test/file.txt');

When trying to load a file we cannot read from disk, an empty Vinyl file will be returned. The contents of this file will be set to null.

Trying to get a directory or any invalid files will also return an empty Vinyl file pointer.

Adding/updating a file

You update file references by using store#add() method. This method take a vinyl file object as parameter.

import File from 'vinyl';
import { create } from 'mem-fs';

const coffeeFile = new File({
  cwd: '/',
  base: '/test/',
  path: '/test/file.coffee',
  contents: new Buffer('test = 123'),
});

const store = create();
store.add(coffeeFile);

Iterating over the file system

Using store#each(cb(file, index)), you can iterate over every file stored in the file system.

Get all files

Using store#all(), you can get every file stored in the file system.

Check existence in the file system

Using store#existsInMemory(), you can check if the file already exists in the file system without loading it from disk.

Stream every file stored in the file system

Using store#stream(), you can create a stream with every file stored in the file system.

Pass stored files through a pipeline

store#pipeline() generates a new map with yielded files in transforms. If no transform is passed, files references are updated.

Similar packages

Other packages similar to mem-fs

mock-fs

The mock-fs package provides a way to mock the file system in Node.js. It allows you to create a virtual file system for testing purposes. Unlike mem-fs, which focuses on in-memory file operations, mock-fs is designed to mock the entire file system, making it suitable for more comprehensive testing scenarios.

fs-extra

The fs-extra package extends the native Node.js file system module with additional methods and features. While it does not provide an in-memory file system, it offers a wide range of file manipulation utilities that can be useful for various file operations. It is more focused on enhancing the existing file system capabilities rather than providing an in-memory solution.

vinyl-fs

The vinyl-fs package is a file system adapter for the Vinyl virtual file format, commonly used in the Gulp build system. It allows you to work with files in a stream-based manner. While it does not provide an in-memory file system, it offers a flexible way to handle file operations in build processes.