# metro-memory-fs

> 🚇 A memory-based implementation of `fs` useful for testing.

Latest version **0.82.5** (published 2025-07-06) · MIT license · 0 weekly downloads

## Install

```sh
npm install metro-memory-fs
pnpm add metro-memory-fs
yarn add metro-memory-fs
bun add metro-memory-fs
```

## Health

**Score 45/100 (D)** — status: stable.

Positive: esm support; no vulnerabilities; high maintenance score.

Warnings: low downloads; no types; pre 1.0.

Negative: stale.

## Facts

| | |
|---|---|
| Version | 0.82.5 |
| Published | 2025-07-06 |
| First published | 2018-03-07 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | ESM + CommonJS |
| Node | >=18.18 |
| Dependencies | 1 |
| Unpacked size | 82 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 5630 |
| Maintainers | fb, metro-bot |

## Links

- npm: https://www.npmjs.com/package/metro-memory-fs
- Repository: https://github.com/facebook/metro
- Homepage: https://github.com/facebook/metro#readme
- Issues: https://github.com/facebook/metro/issues
- npm.io page: https://npm.io/package/metro-memory-fs

## Dependencies (1)

- [flow-enums-runtime](https://npm.io/package/flow-enums-runtime.md) ^0.0.6

## Recent versions

- 0.82.5 (latest) — 2025-07-06
- 0.81.5 (0.81-stable) — 2025-05-06
- 0.81.0-alpha.2 (alpha) — 2024-09-25
- 0.80.12 (0.80-stable) — 2024-09-08
- 0.76.9 (0.76-stable) — 2024-01-30
- 0.82.4 — 2025-05-21
- 0.82.3 — 2025-05-06
- 0.82.2 — 2025-04-29
- 0.82.1 — 2025-03-27
- 0.81.4 — 2025-03-20
- 0.82.0 — 2025-03-06
- 0.81.3 — 2025-03-03
- 0.81.2 — 2025-02-25
- 0.81.1 — 2025-01-30
- 0.81.0 — 2024-10-14
- … 139 more at https://npm.io/package/metro-memory-fs/versions

## README

# Metro

[![MIT licensed](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/react/metro/blob/HEAD/LICENSE)
[![npm package version](https://img.shields.io/npm/v/metro?color=brightgreen)](https://www.npmjs.com/package/metro)
[![react/metro/nightly-tests](https://github.com/react/metro/actions/workflows/nightly-tests.yml/badge.svg)](https://github.com/react/metro/actions/workflows/nightly-tests.yml)
[![Code coverage](https://codecov.io/gh/react/metro/branch/main/graph/badge.svg?token=oMHdoKhFZB)](https://codecov.io/gh/react/metro)
[![Follow @MetroBundler on Twitter](https://img.shields.io/twitter/follow/MetroBundler?style=social)](https://twitter.com/intent/follow?screen_name=MetroBundler)

🚇 The JavaScript bundler for React Native.

- **🚅 Fast**: We aim for sub-second reload cycles, fast startup and quick bundling speeds.
- **⚖️ Scalable**: Works with thousands of modules in a single application.
- **⚛️ Integrated**: Supports every React Native project out of the box.

## Installation

Metro is included with React Native — see the [React Native docs](https://reactnative.dev/docs/getting-started) to quickly get started ⏱️.

To add Metro to an existing project, see our [Getting Started guide](https://metrobundler.dev/docs/getting-started).

## Documentation

All available documentation, including on [configuring Metro](https://metrobundler.dev/docs/configuration), can be found on the [Metro website](https://metrobundler.dev/docs/getting-started).

Source code for documentation is located in this repository under `docs/`.

## Contributing

Metro was previously part of the [react-native](https://github.com/facebook/react-native) repository. In this standalone repository it is easier for the team working on Metro to respond to issues and pull requests. See [react-native#13976](https://github.com/facebook/react-native/issues/13976) for the initial announcement.

### [Code of Conduct](https://code.fb.com/codeofconduct)

Meta has adopted a Code of Conduct that we expect project participants to adhere to. Please read [the full text](https://code.fb.com/codeofconduct) so that you can understand what actions will and will not be tolerated.

### [Contributing guide](https://github.com/react/metro/blob/main/CONTRIBUTING.md)

Read our [contributing guide](https://github.com/react/metro/blob/main/CONTRIBUTING.md) to learn about our development process, how to propose bug fixes and improvements, and how to build and test your changes to Metro.

### Discussions

Larger discussions and proposals concerning React Native and Metro are discussed in [**@react-native-community/discussions-and-proposals**](https://github.com/react-native-community/discussions-and-proposals).

## License

Metro is MIT licensed, as found in the LICENSE file.

---
_Source: https://npm.io/package/metro-memory-fs · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._