ShamRack

ShamRack plumbs HTTP requests into Rack.

What's it for, again?

Well, it makes it easy to stub out external (HTTP) services, which is handy in development and testing environments, or when you want to test your HTTP client code.

You can also use it to test your Rack application (or Sinatra, or Rails, or Merb) using a variety of HTTP client libraries, to check interoperability. For instance, you could test your app using:

all without having to boot it in a server.

Installing it

gem install sham_rack

Using it

A simple inline application

require 'sham_rack'

ShamRack.at("www.greetings.com") do |env|
  ["200 OK", { "Content-type" => "text/plain" }, ["Hello, world!"]]
end

require 'open-uri'
open("http://www.greetings.com/").read            #=> "Hello, world!"

Sinatra integration

ShamRack.at("sinatra.xyz").sinatra do
  get "/hello/:subject" do
    "Hello, #{params[:subject]}"
  end
end

open("http://sinatra.xyz/hello/stranger").read  #=> "Hello, stranger"

Rackup support

ShamRack.at("rackup.xyz").rackup do
  use Some::Middleware
  use Some::Other::Middleware
  run MyApp.new
end

Any old Rack app

ShamRack.at("google.com").mount(my_google_stub)

General-purpose stubbing

@stub_app = ShamRack.at("stubbed.com").stub
@stub_app.register_resource("/greeting", "Hello, world!", "text/plain")

open("http://stubbed.com/greeting").read       #=> "Hello, world!"
@stub_app.last_request.path                    #=> "/greeting"

On a specific port

ShamRack.at("example.com", 8080) do |env|
  ["200 OK", { "Content-type" => "text/plain" }, ["Hello, world!"]]
end

Or, just use Sinatra, as described above ... it's almost as succinct, and heaps more powerful.

Avoiding (accidental) real network connections

ShamRack.prevent_network_connections

When you're done testing

ShamRack.reset

open("http://stubbed.com/greeting").read       #=> OpenURI::HTTPError

Supported HTTP client libraries

Net::HTTP and friends

ShamRack supports requests made using Net::HTTP, or any of the numerous APIs built on top of it:

uri = URI.parse("http://www.greetings.com/")
Net::HTTP.get_response(uri).body                      #=> "Hello, world!"

require 'open-uri'
open("http://www.greetings.com/").read                #=> "Hello, world!"

require 'restclient'
RestClient.get("http://www.greetings.com/").to_s      #=> "Hello, world!"

require 'mechanize'
Mechanize.new.get("http://www.greetings.com/").body   #=> "Hello, world!"

Patron (experimental)

We've recently added support for Patron:

require 'sham_rack/patron'

patron = Patron::Session.new
patron.get("http://www.greetings.com/").body          #=> "Hello, world!"

What's the catch?

Your Rack request-handling code runs in the same Ruby VM, in fact the same Thread, as your request.

Thanks to

Blaine Cook for FakeWeb, which was an inspiration for ShamRack.
Perryn Fowler for his efforts plumbing Net::HTTP into ActionController::TestProcess.
Christian Neukirchen et al for the chewy goodness that is Rack.

mdub/sham_rack