# @ruby2js/ruby2js

> Ruby to Javascript transpiler

Latest version **5.1.2** (published 2024-05-11) · MIT license · 0 weekly downloads

## Install

```sh
npm install @ruby2js/ruby2js
pnpm add @ruby2js/ruby2js
yarn add @ruby2js/ruby2js
bun add @ruby2js/ruby2js
```

## Health

**Score 30/100 (F)** — status: abandoned.

Positive: esm support; no vulnerabilities.

Warnings: low downloads; no types.

Negative: abandoned.

## Facts

| | |
|---|---|
| Version | 5.1.2 |
| Published | 2024-05-11 |
| First published | 2021-02-28 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | ESM + CommonJS |
| Node | >= 14 |
| Dependencies | 0 |
| Unpacked size | 4.3 MB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 491 |
| Maintainers | jaredwhite, rubys |
| Keywords | ruby2js |

## Links

- npm: https://www.npmjs.com/package/@ruby2js/ruby2js
- Repository: https://github.com/ruby2js/ruby2js
- Homepage: https://www.ruby2js.com/
- Issues: https://github.com/ruby2js/ruby2js/issues
- npm.io page: https://npm.io/package/@ruby2js/ruby2js

## Recent versions

- 5.1.2 (latest) — 2024-05-11
- 5.1.1 — 2024-01-05
- 5.1.0 — 2023-02-20
- 5.0.1 — 2022-05-14
- 5.0.0 — 2022-05-14
- 0.2.1 — 2021-11-13
- 0.2.0 — 2021-10-11
- 0.1.10 — 2021-09-21
- 0.1.9 — 2021-09-19
- 0.1.8 — 2021-08-19
- 0.1.7 — 2021-08-14
- 0.1.6 — 2021-04-13
- 0.1.5 — 2021-04-11
- 0.1.4 — 2021-03-30
- 0.1.3 — 2021-03-26
- … 7 more at https://npm.io/package/@ruby2js/ruby2js/versions

## README

# Ruby2JS

Minimal yet extensible Ruby to JavaScript conversion.

[![Gem Version](https://badge.fury.io/rb/ruby2js.svg)](https://badge.fury.io/rb/ruby2js)
[![CI](https://github.com/ruby2js/ruby2js/actions/workflows/ci.yml/badge.svg)](https://github.com/ruby2js/ruby2js/actions/workflows/ci.yml)

**[Documentation](https://www.ruby2js.com)** | **[Live Demo](https://ruby2js.com/demo?preset=true)**

## Installation

```ruby
# Gemfile
gem 'ruby2js'
```

Or install directly:

```sh
gem install ruby2js
```

## Examples

Ruby2JS converts Ruby syntax to clean, readable JavaScript:

```ruby
# Ruby                              # JavaScript
a = { age: 3 }                      # let a = {age: 3}
a.age += 1                          # a.age++

items.map { |x| x * 2 }             # items.map(x => x * 2)

class Dog < Animal                  # class Dog extends Animal {
  def bark                          #   bark() {
    puts "woof!"                    #     console.log("woof!")
  end                               #   }
end                                 # }
```

## Quick Start

```ruby
require 'ruby2js'

puts Ruby2JS.convert("a = {age: 3}; a.age += 1", preset: true)
# => let a = {age: 3}; a.age++
```

### Command Line

```sh
ruby2js --preset file.rb
echo "puts 'hello'" | ruby2js --preset
```

## Features

- **[Filters](https://www.ruby2js.com/docs/filters)** - Transform Ruby methods to JavaScript equivalents (e.g., `.each` → `.forEach`)
- **[ES Level Support](https://www.ruby2js.com/docs/eslevels)** - Target specific JavaScript versions (ES2020 through ES2025)
- **[Framework Integrations](https://www.ruby2js.com/docs/integrations)** - Rails, Stimulus, React, Lit, and more
- **[Live Demo](https://ruby2js.com/demo?preset=true)** - Try it in your browser (runs entirely client-side via Opal)

## Demos

- **[Opal Demo](https://ruby2js.com/demo?preset=true)** - Full-featured demo using Opal (~5MB)
- **[Selfhost Demo](https://ruby2js.com/demo/selfhost/)** - Lightweight demo using transpiled Ruby2JS (~200KB + Prism WASM)
- **[Ruby2JS-on-Rails](https://ruby2js.com/demo/ruby2js-on-rails/)** - Rails-like blog app running entirely in JavaScript

The selfhost demo runs Ruby2JS transpiled to JavaScript, demonstrating that Ruby2JS can convert itself. The Ruby2JS-on-Rails demo shows a complete Rails-style MVC application with ActiveRecord, controllers, and ERB views running in the browser or on Node.js/Bun/Deno.

## Contributing

### Running Tests

```sh
bundle install
bundle exec rake test_all
```

### Running the Website Locally

The [ruby2js.com](https://www.ruby2js.com) website (including the live demo) can be run locally from the `docs` folder:

```sh
cd docs
bundle install
yarn install
bundle exec rake            # build demo assets (Opal-compiled ruby2js, etc.)
bin/bridgetown start        # run the site's dev server
```

The site will be available at `http://localhost:4000`.

## Release Process for Maintainers

1. Update the version in both `packages/ruby2js/package.json` and `lib/ruby2js/version`, ensuring they match.
2. Run `bundle exec rake release_core`

## License

MIT License - Copyright (c) 2009, 2025 Macario Ortega, Sam Ruby, Jared White

See [LICENSE](LICENSE) for details.

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_Source: https://npm.io/package/@ruby2js/ruby2js · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._