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A generic file system abstraction for Dart.

This package is currently experimental and subject to change

Like dart:io, package:file supplies a rich Dart idiomatic API for accessing a file system.

Unlike dart:io, package:file:

  • Does not mix synchronous and asynchronous API in one. It is up to users to choose one, the other, or both.

  • Has explicit factory classes for different implementations.
  • Can be used to implement custom file systems.
  • Comes with in-memory implementation out-of-the-box, making it super-easy to test code that works with the file system.


Implement your own custom file system:

import 'package:file/file.dart';

class FooBarFileSystem implements FileSystem { ... }

Use the in-memory file system:

import 'package:file/file.dart';

var fs = new InMemoryFileSystem();

Use the local file system (requires dart:io access):

import 'package:file/io.dart';

var fs = const LocalFileSystem();

The synchronous counterparts can be imported from:

// API and in-memory implementation
import `package:file/sync.dart`;
// Implementation based on "dart:io"
import `package:file/sync_io.dart`;



The synchronous clone of the file.dart API.

Common tests that can be re-used across backends.