Jeanine

A Ruby micro-web-framework that gives you enough training wheels to be productive, while being as nearly as fast as Rack itself.

Its design (and some parts of the code) is influenced by/inherited from (thanks!) Ruby on Rails, Rack::App, Hobbit, and Cuba. Without them this is nothing.

Name

Named after my mom. Because she was the best.

Installation

Add this line to your application's Gemfile:

gem 'jeanine'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install jeanine

Basic usage

Drop this into config.ru:

require 'bundler/setup'
require 'jeanine'

class App < Jeanine::App
  root do
    "Hello world"
  end
end

run App 

$ rackup

Or generate a new app:

$ gem install jeanine
$ jeanine new my_api
$ cd my_api
$ bundle
$ rackup 

Advanced usage

class App < Jeanine::App 
  path "/posts" do 
    get do 
      if request.json?
        render json: []
      else
        "Posts index"
      end
    end 
    
    get "new" do 
      "Posts new"
    end
    
    post do 
      "Posts post"
    end 
    
    path ":id" do 
      get do 
        "Posts #{params[:id]}"
      end
      
      match via: [:put, :patch] do 
        "Posts #{request.via} #{params[:id]}"
      end
      
      delete do
        "Posts delete #{params[:id]}" 
      end 
      
      path "/comments" do
        get do 
          "Posts #{params[:id]} comments"
        end 
      end
    end 
  end 
end 

Plugins

Callbacks

Supports before and after callbacks (same DSL):

class App < Jeanine::App
  plugin :Callbacks 
  
  before do 
    puts "All"
  end
  
  before /posts/ do
    puts "Before posts"
  end 
  
  before /posts\/\d*/, /comments\/\d*/  do 
    puts "Before posts/:id, comments/:id"
    response.headers['X-Thing-Id'] = params[:id]
  end 
end 

Rendering

Basic support for rendering. Be explicit.

class App < Jeanine::App
  plugin :Rendering 
  
  # loads views/root.html.erb and views/layouts/application.html.erb
  root do 
    @title = "My cool app"
    render template: "root.html.erb", layout: "application.html.erb"
  end
end 

Sessions

Uses Rack's session management.

class App < Jeanine::App
  plugin :Session
  
  root do 
    session[:uid] = SecureRandom.hex
  end
end 

Error handling

class App < Jeanine::App
  plugin :Rescuable 
  
  rescue_from NoMethodError, RuntimeError do |exception|
    response.status = 500
    "Oh no!"
  end
  
  rescue_from StandardError, with: :handle_error!
  
  root do 
    @title = "My cool app"
    raise NoMethodError 
    render template: "root.html.erb", layout: "application.html.erb"
  end

  private 
  
  def handle_error!(exception)
    response.status = 500
    render template: "error.html.erb" 
  end
end 

Development

Ideologies

• No meaningless metaprogramming = fast

Benchmarks

Requests/second

Benched on a Intel Core i7-8700B / 64GB RAM.

Framework            Requests/sec  % from best
----------------------------------------------
rack                     17299.31      100.00%
jeanine                  16022.71       92.62%
rack-response            15462.50       89.38%
syro                     15416.13       89.11%
watts                    15307.52       88.49%
roda                     14550.56       84.11%
hanami-router            14342.92       82.91%
cuba                     14246.23       82.35%
hobbit                   14132.20       81.69%
rambutan                 12526.40       72.41%
rack-app                 11696.66       67.61%
flame                     7931.61       45.85%
rails-metal               7761.75       44.87%
sinatra                   4616.81       26.69%
grape                     2401.66       13.88%
hobby                     1805.93       10.44%
rails-api                 1593.77        9.21%

Memory

Framework       Allocs/Req Memsize/Req
--------------------------------------
rack                    40        3408
roda                    43        4016
syro                    44        4288
cuba                    44        4056
watts                   46        3648
hobbit                  48        4416
jeanine                 52        4576
hobby                   52        5416
rack-response           55        5128
rails-metal             59        5848
hanami-router           63        5184
rambutan                79        6944
rack-app                80        8424
flame                  115        9648
sinatra                179       13440
grape                  250       26704
rails-api              383       34949

Todo

• Callback constraints
• File downloads

Contributing

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

License

The gem is available as open source under the terms of the MIT License.