schmooze 0.1.2

# 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](https://nodejs.org/en/) installed and in the `$PATH`. ## Gem Installation Add this line to your application's Gemfile: ```ruby gem 'schmooze' ``` And then execute: $ bundle ## 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](https://babeljs.io/): ```ruby 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](#caveats)). ```ruby $ 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: ```ruby 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): ```ruby 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). ## Contributing Bug reports and pull requests are welcome on GitHub at https://github.com/Shopify/schmooze.