fs4f - In-memory File System for Fun

This project is a weekend project to teach myself more about Typescript with node.js.

The purpose is to design an in-memory file system library. This is by no means production level library. If you are looking for a serious in-memory file system check out tmpfs or, more specifcally for Node.js, memfs.

Building

I am using node v16. I recommend using Volta to automatically pick the right runtime version.

When you first check out, install the dependencies by running npm install

To build the library run: npm run build. The build output is ES6 compatible JavaScript. The files are using CommonJS module format.

Testing

To run tests: npm run test. Tests use the Jest test framework.

You can also keep the tests running when the files change: npm run test:watch.

The test output should include information about the code coverage.

How to use it

To use the in-memory file system, simply instantiate the FileSystem object.

The File System is very basic, has no concept of volumes or persistance. The FS is created with a root directory. The .. has a special meaning and allows you to traverse the path to the parent.

Example usage:

    import { FileSystem } from './src/fs.ts';

    const fs = new FileSystem();
    const rootDir = fs.root; // Pointer to the root directory

    // Create directories
    const dir = fs.createDir("/tmp/path"); // tmp and path were created

    // Create files and write
    const file = fs.createFile("/tmp/log.txt"); // log.txt was created
    file.write("Log line"); // Write log.txt to the file contents
    console.log(file.contents); // Prints Log Line

    // Change working dir
    fs.changeDir("/tmp");

    // List items in a dir
    fs.currentDir().items.forEach(item => console.log(item.name));

    // Remove a directory
    fs.removeDir("/tmp/path"); // path was removed

    // Find files
    const results = fs.find("log.txt"); // Returns [File] array

Features

Each file system item has a name and metadata (creation and modification timestamp)
Directories
- change current directory
- create a new directory
- list directory contents
- create new directories using relative and absolute paths
- remove directories
Files
- create files
- delete files
- write strings to files as UTF-8 byte array
You can search for files using exact match
File system is case sensitive
You can use / in the directory name if it's escaped with \ e.g. Foo \/ Bar is a valid dir name.

Ideas for more features