Schmooze

Schmooze lets Ruby and Node.js work together intimately. It has a DSL that allows you to define what methods you need, and it executes code by spawning a Node.js process and sending messages back and forth.

Requirements

Schmooze requires that you have nodejs installed and in the $PATH.

Gem Installation

Add this line to your application's Gemfile:

gem 'schmooze'

And then execute:

$ bundle

Using the speee/schmooze fork

If you need the latest bug fixes (including the finalizer freeze fix), you can use the speee/schmooze fork:

gem 'schmooze', github: 'speee/schmooze', tag: 'v26.1.1'

Usage

To use Schmooze, you first need to create a sublcass of Schmooze::Base. Your subclass needs to list all of the package dependencies, and methods that you want to have available. For example, here is a Schmooze class that interfaces with Babel:

require 'schmooze'

class BabelSchmoozer < Schmooze::Base
  dependencies babel: 'babel-core'

  method :transform, 'babel.transform'
  method :version, 'function() { return [process.version, babel.version]; }'
end

Note that the babel-core package is available under the name babel, because that's how we requested it.

To define a method, you simply give it a name and pass in a JavaScript string that should resolve to a function. Let's put this class to use!

First we need to make sure we install any needed packages.

$ npm install babel-core babel-preset-es2015

All we need to do next is to instantiate the class with a path to where the node modules are installed, and then we can call the methods! (Note that we need to pass in ast: false because of a caveat).

$ pry
Ruby 2.2.2
pry> load './babel_schmoozer.rb'
pry> babel = BabelSchmoozer.new(__dir__)
pry> babel.version
=> ["v5.5.0", "6.5.2"]
pry> puts babel.transform('a = () => 1', ast: false, presets: ['es2015'])['code']
"use strict";

a = function a() {
  return 1;
};

This could easily be turned into a Sprockets plugin.

Error handling

Errors happen, and Schmooze tries to make them as painless as possible to handle. If there is a dependency missing, Schmooze will throw a helpful Error when you try to initialize the class. Here is an example from the tests:

class ErrorSchmoozer < Schmooze::Base
  dependencies nonexistant: 'this-package-is-not-here'
end
ErrorSchmoozer.new(__dir__)

This will raise

Schmooze::DependencyError: Cannot find module 'this-package-is-not-here'.
You need to add it to '/Users/bouke/code/schmooze/test/fixtures/uninstalled_package/package.json' and run 'npm install'

Any JavaScript errors that happen get converted to Ruby errors under the Schmooze::Javascript namespace. For example (once again, from the tests):

class CoffeeSchmoozer < Schmooze::Base
  dependencies coffee: 'coffee-script'
  method :compile, 'coffee.compile'
end

CoffeeSchmoozer.new(__dir__).compile('<=> 1')

This will raise

Schmooze::JavaScript::SyntaxError: [stdin]:1:1: error: unexpected <=
 <=> 1
 ^^

Caveats

• Because we serialize the return values from JavaScript to JSON, you can't return circular data structures (like the Babel AST).

Changes in speee/schmooze fork

The speee/schmooze fork includes the following improvements:

• Fix close() method hanging - Fixed an issue where the close() method would hang indefinitely when used with long-running Node.js processes (e.g., processes using setTimeout or event listeners). The fix ensures the process is terminated before waiting for it to exit.
• Ruby 3.4 and 4.0 support - Added support for Ruby 3.4 and Ruby 4.0 with minitest 6.x compatibility.
• Docker test setup - Added Docker configuration for testing across multiple Ruby versions (2.6 - 4.0).
• CI improvements - Updated GitHub Actions workflow with Ruby 3.4/4.0 support and dependency updates.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Shopify/schmooze.

For the speee fork, please submit issues and pull requests at https://github.com/speee/schmooze.

Make sure the tests pass

Run the setup script

$ ./script/setup

Run the tests

$ ./script/test