fsa-promises

Web File System API to Node fs promises API.

Learn more about: File System API

Note

This library was originally implemented for use with isomorphic-git. But the actual test found that the performance was so bad and there were inexplicable problems, so I gave up. ☹️

Install

# npm
npm install @tsuk1ko/fsa-promises

# yarn
yarn add @tsuk1ko/fsa-promises

# bun
bun add @tsuk1ko/fsa-promises

Usage

import { FsaPromises } from 'fsa-promises';

// Use `navigator.storage.getDirectory()` as root
const fs = new FsaPromises();

// Use directory "path/to/some/dir" of `navigator.storage.getDirectory()` as root,
// will be create recursively if not exists
const fs = new FsaPromises('path/to/some/dir');

// Use `showDirectoryPicker()` to select a directory as root
const fs = new FsaPromises(showDirectoryPicker({ mode: 'readwrite' }));

// Use almost the same way as node fsPromises module
await fs.writeFile('file.txt', 'hello world');

APIs

new FsaPromises([options])

options can be string, FileSystemDirectoryHandle, Promise<FileSystemDirectoryHandle> or an FsaPromisesOptions object.

interface FsaPromisesOptions {
  root?: string | FileSystemDirectoryHandle | Promise<FileSystemDirectoryHandle>;
  useSyncAccessHandleForFile?: boolean;
}

useSyncAccessHandleForFile

When it is true, the library will use createSyncAccessHandle() instead of createWritable() to write file.

It is only usable inside dedicated Web Workers with the origin private file system.

For more information, please check here.

readFile(path[, options])

Refer to fsPromises.readFile.

flag and signal are not supported.

writeFile(file, data[, options])

Refer to fsPromises.writeFile.

mode is not supported.

flush is usable only when useSyncAccessHandleForFile is true.

signal is not usable when useSyncAccessHandleForFile is true.

unlink(path)

Refer to fsPromises.unlink.

readdir(path[, options])

Refer to fsPromises.readdir.

encoding only support undefine, null or "buffer".

mkdir(path[, options])

Refer to fsPromises.mkdir.

mode is not supported.

rmdir(path[, options])

Refer to fsPromises.rmdir.

maxRetries and retryDelay are not supported.

exist(path)

This API does not exist in node fsPromises. It is provided for convenience.

stat(path[, options])

Refer to fsPromises.stat.

lstat(path[, options])

Same as stat() because symlink isn't implemented.

readlink(path[, options])

Not implemented, don't use.

symlink(target, path[, type])

Not implemented, don't use.

chmod(path, mode)

Do nothing, just for compatibility.