Rack Web Console is a simple Rack app class that allows one to run arbitrary Ruby code on a given
binding, which may be useful in development mode to test some code in a given context. This is
similar to the rails-web-console
(it was indeed extracted from it with a few enhancements) but
works for any Rack based application, including Rails.
Add this line to your application's Gemfile:
gem 'rack_web_console'
And then execute:
$ bundle
Or install it yourself as:
$ gem install rack_web_console
The hello world is not much useful, but here you are:
# config.ru
require 'rack_web_console'
run RackConsole.new binding
Usually, you'd be more interested in learning about the binding which is usually a controller
or something like that. For example, if you want to test code from inside a Roda's route
block:
# config.ru
require 'roda'
require 'rack_web_console'
class App < Roda
route do |r|
r.on('console'){ halt RackConsole.new(binding) } if ENV['RACK_ENV'] == 'development'
'default response'
end
end
run App
The local variable r
would be available in the console for example in this case. Some
frameworks may not have a method like Roda's halt
, so in a Rails application for example,
you may have to do this:
# app/controllers/console_controller.rb:
require 'rack_web_console'
class ConsoleController < ApplicationController
skip_before_action :verify_authenticity_token
def index
status, headers, body = RackConsole.new(binding).call(request.env)
response.headers.merge headers
render inline: body.join("\n"), status: status
end
end
# routes.rb:
Rails.application.routes.draw do
# ...
match 'console' => 'console#index', via: [:get, :post] if Rails.env.development?
end
This example demonstrates how to use it with a Rails project, but it could be used with basically any framework. If you're not really interested on some specific binding, you can simply mount it directly in config.ru:
# config.ru
require_relative 'config/environment'
require 'rack_web_console'
map('/console'){ run RackConsole.new }
run Rails.application
By default, only the output of the request thread is sent to the POST request response. If you
want to spawn new threads from the script and see the output of all threads, set the
:rack_console_capture_all
thread local to true:
Thread.current[:rack_console_capture_all] = true
Thread.start{ puts 'now it should be displayed in the browser' }.join
- Ctrl+Enter: Run code
- Esc, Esc: Clear output
After checking out the repo, run bin/setup
to install dependencies. Then, run rake spec
to run the tests. You can also run bin/console
for an interactive prompt that will allow
you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a
new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and
push the .gem
file to rubygems.org.
Bug reports and pull requests are welcome on GitHub.
The gem is available as open source under the terms of the MIT License.