Testing Sinatra with Rack::Test

All examples in the following sections assume that Test::Unit is being used in an attempt to be as general as possible. See the Test Framework Examples for information on using the test helpers in other testing environments. To use the Rack::Test library used when you require rack/test, you’ll need to install the rack-test gem:

gem install rack-test

You can also add it to your applications Gemfile like this:

gem 'rack-test'

Example App: `hello_world.rb`

The following example app is used to illustrate testing features. This is assumed to be in a file named hello_world.rb:

require 'sinatra'

get '/' do
  "Hello World #{params[:name]}".strip
end

Using The `Rack::Test::Methods` Mixin

The Rack::Test::Methods module includes a variety of helper methods for simulating requests against an application and asserting expectations about the response. It’s typically included directly within the test context and makes a few helper methods and attributes available.

The following is a simple example that ensures the hello world app functions properly:

ENV['APP_ENV'] = 'test'

require 'hello_world'
require 'test/unit'
require 'rack/test'

class HelloWorldTest < Test::Unit::TestCase
  include Rack::Test::Methods

  def app
    Sinatra::Application
  end

  def test_it_says_hello_world
    get '/'
    assert last_response.ok?
    assert_equal 'Hello World', last_response.body
  end

  def test_it_says_hello_to_a_person
    get '/', :name => 'Simon'
    assert last_response.body.include?('Simon')
  end
end

Using `Rack::Test` without the Mixin

For a variety of reasons you may not want to include Rack::Test::Methods into your own classes. Rack::Test supports this style of testing as well, here is the above example without using Mixin.

ENV['APP_ENV'] = 'test'

require 'hello_world'
require 'test/unit'
require 'rack/test'

class HelloWorldTest < Test::Unit::TestCase

  def test_it_says_hello_world
    browser = Rack::Test::Session.new(Rack::MockSession.new(Sinatra::Application))
    browser.get '/'
    assert browser.last_response.ok?
    assert_equal 'Hello World', browser.last_response.body
  end

  def test_it_says_hello_to_a_person
    browser = Rack::Test::Session.new(Rack::MockSession.new(Sinatra::Application))
    browser.get '/', :name => 'Simon'
    assert browser.last_response.body.include?('Simon')
  end
end

Rack::Test’s Mock Request Methods

The get, put, post, delete, and head methods simulate the respective type of request on the application. Tests typically begin with a call to one of these methods followed by one or more assertions against the resulting response.

All mock request methods have the same argument signature:

get '/path', params={}, rack_env={}

/path is the request path and may optionally include a query string.
params is a Hash of query/post parameters, a String request body, or nil.
rack_env is a Hash of Rack environment values. This can be used to set request headers and other request related information, such as session data. See the Rack SPEC for more information on possible key/values.

Asserting Expectations About The Response

Once a request method has been invoked, the following attributes are available for making assertions:

app - The Sinatra application class that handled the mock request.
last_request - The Rack::MockRequest used to generate the request.
last_response - A Rack::MockResponse instance with information on the response generated by the application.

Assertions are typically made against the last_response object. Consider the following examples:

def test_it_says_hello_world
  get '/'
  assert last_response.ok?
  assert_equal 'Hello World'.length.to_s, last_response.headers['Content-Length']
  assert_equal 'Hello World', last_response.body
end

Optional Test Setup

The Rack::Test mock request methods send requests to the return value of a method named app.

If you’re testing a modular application that has multiple Sinatra::Base subclasses, simply set the app method to return your particular class.

  def app
    MySinatraApp
  end

If you’re using a classic style Sinatra application, then you need to return an instance of Sinatra::Application.

  def app
    Sinatra::Application
  end

Making `Rack::Test` available to all test cases

If you’d like the Rack::Test methods to be available to all test cases without having to include it each time, you can include the Rack::Test module in the Test::Unit::TestCase class:

require 'test/unit'
require 'rack/test'

class Test::Unit::TestCase
  include Rack::Test::Methods
end

Now all TestCase subclasses will automatically have Rack::Test available to them.

Test Framework Examples

As of version 0.9.1, Sinatra no longer provides testing framework-specific helpers. Those found in sinatra/test/*.rb are deprecated and has been removed in Sinatra 1.0.

RSpec

Sinatra can be tested under plain RSpec. The Rack::Test module should be included within the describe block:

ENV['APP_ENV'] = 'test'

require 'hello_world'  # <-- your sinatra app
require 'rspec'
require 'rack/test'

RSpec.describe 'The HelloWorld App' do
  include Rack::Test::Methods

  def app
    Sinatra::Application
  end

  it "says hello" do
    get '/'
    expect(last_response).to be_ok
    expect(last_response.body).to eq('Hello World')
  end
end

Make Rack::Test available to all spec contexts by including it via RSpec:

require 'rspec'
require 'rack/test'

RSpec.configure do |conf|
  conf.include Rack::Test::Methods
end

Test::Spec

The Rack::Test module should be included within the context of the describe block:

ENV['APP_ENV'] = 'test'

require 'hello_world'  # <-- your sinatra app
require 'test/spec'
require 'rack/test'

describe 'The HelloWorld App' do
  include Rack::Test::Methods

  def app
    Sinatra::Application
  end

  it "says hello" do
    get '/'
    last_response.should.be.ok
    last_response.body.should.equal 'Hello World'
  end
end

Make Rack::Test available to all spec contexts by including it in Test::Unit::TestCase:

require 'test/spec'
require 'rack/test'

Test::Unit::TestCase.send :include, Rack::Test::Methods

Capybara

Capybara will use Rack::Test by default. You can use another driver, like Selenium, by setting the default_driver.

ENV['APP_ENV'] = 'test'

require 'hello_world'  # <-- your sinatra app
require 'capybara'
require 'capybara/dsl'
require 'test/unit'

class HelloWorldTest < Test::Unit::TestCase
  include Capybara::DSL
  # Capybara.default_driver = :selenium # <-- use Selenium driver

  def setup
    Capybara.app = Sinatra::Application.new
  end

  def test_it_works
    visit '/'
    assert page.has_content?('Hello World')
  end
end