execjs

ExecJS lets you run JavaScript code from Ruby.

$gem install execjs

Official docs outline

Extra Credit builds an outline of execjs's docs the first time your work uses it. Until then, start at the official documentation.

logger Provides a simple logging utility for outputting messages.
hashdiff Hashdiff is a diff lib to compute the smallest difference between two hashes.
webmock WebMock allows stubbing HTTP requests and setting expectations on HTTP requests.
terminal-table Simple, feature rich ascii table generation library
faraday-retry Catches exceptions and retries each request a limited number of times.
crack Really simple JSON and XML parsing, ripped from Merb and Rails.
retriable Retriable is a simple DSL to retry failed code blocks with randomized exponential backoff. This is especially useful when interacting with e
rspec-rails rspec-rails integrates the Rails testing helpers into RSpec.
faraday-multipart Perform multipart-post requests using Faraday.
listen The Listen gem listens to file modifications and notifies you about the changes. Works everywhere!
sawyer Secret User Agent of HTTP
faraday-excon Faraday adapter for Excon