rspec-rails-2

rspec-2 for rails-3 with lightweight extensions to each

Note: Use rspec-rails-1.3 for rails-2.

Install

gem install rspec-rails

This installs the following gems:

rspec
rspec-core
rspec-expectations
rspec-mocks
rspec-rails

Configure

Add rspec-rails to the :test and :development groups in the Gemfile:

group :test, :development do
  gem "rspec-rails", "~> 2.6"
end

It needs to be in the :development group to expose generators and rake
tasks without having to type RAILS_ENV=test.

Now you can run:

rails generate rspec:install

This adds the spec directory and some skeleton files, including
the “rake spec” task.

Generators

If you type script/rails generate, the only RSpec generator you’ll actually
see is rspec:install. That’s because RSpec is registered with Rails as the
test framework, so whenever you generate application components like models,
controllers, etc, RSpec specs are generated instead of Test::Unit tests.

Please note that the generators are there to help you get started, but they are
no substitute for writing your own examples, and they are only guaranteed to
work out of the box for the default scenario (ActiveRecord & Webrat).

Webrat and Capybara

You can choose between webrat or capybara for simulating a browser, automating
a browser, or setting expectations using the matchers they supply. Just add
your preference to the Gemfile:

gem "webrat"
gem "capybara"

Living on edge

Bundler makes it a snap to use the latest code for any gem your app depends on. For
rspec-rails, you’ll need to point bundler to the git repositories for rspec-rails
and the other rspec related gems it depends on:

gem "rspec-rails",        :git => "git://github.com/rspec/rspec-rails.git"
gem "rspec",              :git => "git://github.com/rspec/rspec.git"
gem "rspec-core",         :git => "git://github.com/rspec/rspec-core.git"
gem "rspec-expectations", :git => "git://github.com/rspec/rspec-expectations.git"
gem "rspec-mocks",        :git => "git://github.com/rspec/rspec-mocks.git"

Run bundle install and you’ll have whatever is in git right now. Any time you
want to update to a newer head, just run bundle update.

Keep in mind that each of these codebases is under active development, which
means that its entirely possible that you’ll pull from these repos and they won’t
play nice together. If playing nice is important to you, stick to the published
gems.

Backwards compatibility

This is a complete rewrite of the rspec-rails extension designed to work with
rails-3.x and rspec-2.x. It will not work with older versions of either rspec
or rails. Many of the APIs from rspec-rails-1 have been carried forward,
however, so upgrading an app from rspec-1/rails-2, while not pain-free, should
not send you to the doctor with a migraine.

Known issues

See http://github.com/rspec/rspec-rails/issues

Request Specs

Request specs live in spec/requests, and mix in behavior
ActionDispatch::Integration::Runner,
which is the basis for Rails’ integration
tests. The
intent is to specify one or more request/response cycles from end to end using
a black box approach.

describe "home page" do
  it "displays the user's username after successful login" do
    user = User.create!(:username => "jdoe", :password => "secret")
    get "/login"
    assert_select "form.login" do
      assert_select "input[name=?]", "username"
      assert_select "input[name=?]", "password"
      assert_select "input[type=?]", "submit"
    end

    post "/login", :username => "jdoe", :password => "secret"
    assert_select ".header .username", :text => "jdoe"
  end
end

This example uses only standard Rails and RSpec API’s, but many RSpec/Rails
users like to use extension libraries like FactoryGirl and Capybara:

describe "home page" do
  it "displays the user's username after successful login" do
    user = Factory(:user, :username => "jdoe", :password => "secret")
    visit "/login"
    fill_in "Username", :with => "jdoe"
    fill_in "Password", :with => "secret"
    click_button "Log in"

    page.should have_selector(".header .username", :text => "jdoe")
  end
end

FactoryGirl decouples this example from changes to validation requirements,
which can be encoded into the underlying factory definition without requiring
changes to this example.

Among other benefits, Capybara binds the form post to the generated HTML, which
means we don’t need to specify them separately.

There are several other Ruby libs that implement the factory pattern or provide
a DSL for request specs (a.k.a. acceptance or integration specs), but
FactoryGirl and Capybara seem to be the most widely used. Whether you choose
these or other libs, we strongly recommend using something for each of these
roles.

Controller Specs

Controller specs live in spec/controllers, and mix in
ActionController::TestCase::Behavior, which is the basis for Rails’ functional
tests.

with fixtures

describe WidgetsController do
  describe "GET index" do
    fixtures :widgets

    it "assigns all widgets to @widgets" do
      get :index
      assigns(:widgets).should eq(Widget.all)
    end
  end
end

with a factory

describe WidgetsController do
  describe "GET index" do
    it "assigns all widgets to @widgets" do
      widget = Factory(:widget)
      get :index
      assigns(:widgets).should eq([widget])
    end
  end
end

with stubs

describe WidgetsController do
  describe "GET index" do
    it "assigns all widgets to @widgets" do
      widget = stub_model(Widget)
      Widget.stub(:all) { [widget] }
      get :index
      assigns(:widgets).should eq([widget])
    end
  end
end

matchers

In addition to the stock matchers from rspec-expectations, controller
specs add these matchers, which delegate to rails’ assertions:

response.should render_template(*args)
# => delegates to assert_template(*args)

response.should redirect_to(destination)
# => delegates to assert_redirected_to(destination)

isolation from views

RSpec’s preferred approach to spec'ing controller behaviour is to isolate
the controller from its collaborators. By default, therefore, controller
example groups do not render the views in your app. Due to the way Rails
searches for view templates, the template still needs to exist, but it
won’t actually be loaded.

NOTE that this is different from rspec-rails-1 with rails-2, which did not
require the presence of the file at all. Due to changes in rails-3, this
was no longer feasible in rspec-rails-2.

render_views

If you prefer a more integrated approach, similar to that of Rails’
functional tests, you can tell controller groups to render the views in the
app with the render_views declaration:

describe WidgetsController do
  render_views
  # ...

Upgrade note

render_views replaces integrate_views from rspec-rails-1.3

assigns

Use assigns(key) to express expectations about instance variables that a controller
assigns to the view in the course of an action:

get :index
assigns(:widgets).should eq(expected_value)

View specs

View specs live in spec/views, and mix in ActionView::TestCase::Behavior.

describe "events/index" do
  it "renders _event partial for each event" do
    assign(:events, [stub_model(Event), stub_model(Event)])
    render
    view.should render_template(:partial => "_event", :count => 2)
  end
end

describe "events/show" do
  it "displays the event location" do
    assign(:event, stub_model(Event,
      :location => "Chicago"
    ))
    render
    rendered.should contain("Chicago")
  end
end

View specs infer the controller name and path from the path to the view
template. e.g. if the template is “events/index.html.erb” then:

controller.controller_path == "events"
controller.request.path_parameters[:controller] == "events"

This means that most of the time you don’t need to set these values. When
spec'ing a partial that is included across different controllers, you may
need to override these values before rendering the view.

To provide a layout for the render, you’ll need to specify both the template
and the layout explicitly. For example:

render :template => "events/show", :layout => "layouts/application"

assign(key, val)

Use this to assign values to instance variables in the view:

assign(:widget, stub_model(Widget))
render

The code above assigns stub_model(Widget) to the @widget variable in the view, and then
renders the view.

Note that because view specs mix in ActionView::TestCase behavior, any
instance variables you set will be transparently propagated into your views
(similar to how instance variables you set in controller actions are made
available in views). For example:

@widget = stub_model(Widget)
render # @widget is available inside the view

RSpec doesn’t officially support this pattern, which only works as a
side-effect of the inclusion of ActionView::TestCase. Be aware that it may be
made unavailable in the future.

Upgrade note

# rspec-rails-1.x
assigns[key] = value

# rspec-rails-2.x
assign(key, value)

rendered

This represents the rendered view.

render
rendered.should =~ /Some text expected to appear on the page/

Upgrade note

# rspec-rails-1.x
render
response.should xxx

# rspec-rails-2.x
render
rendered.should xxx

Model specs

Model specs live in spec/models.

describe Articles do
  describe ".recent" do
    it "includes articles published less than one week ago" do
      article = Article.create!(:published_at => Date.today - 1.week + 1.second)
      Article.recent.should eq([article])
    end

    it "excludes articles published at midnight one week ago" do
      article = Article.create!(:published_at => Date.today - 1.week)
      Article.recent.should be_empty
    end

    it "excludes articles published more than one week ago" do
      article = Article.create!(:published_at => Date.today - 1.week - 1.second)
      Article.recent.should be_empty
    end
  end
end

Routing specs

Routing specs live in spec/routing.

describe "routing to profiles" do
  it "routes /profile/:username to profile#show for username" do
    { :get => "/profiles/jsmith" }.should route_to(
      :controller => "profiles",
      :action => "show",
      :username => "jsmith"
    )
  end

  it "does not expose a list of profiles" do
    { :get => "/profiles" }.should_not be_routable
  end
end

Upgrade note

route_for from rspec-rails-1.x is gone. Use route_to and be_routable instead.

Helper specs

Helper specs live in spec/helpers, and mix in ActionView::TestCase::Behavior.

Provides a helper object which mixes in the helper module being spec’d, along
with ApplicationHelper (if present).

describe EventsHelper do
  describe "#link_to_event" do
    it "displays the title, and formatted date" do
      event = Event.new("Ruby Kaigi", Date.new(2010, 8, 27))
      # helper is an instance of ActionView::Base configured with the
      # EventsHelper and all of Rails' built-in helpers
      helper.link_to_event.should =~ /Ruby Kaigi, 27 Aug, 2010/
    end
  end
end

Matchers

rspec-rails exposes domain-specific matchers to each of the example group types. Most
of them simply delegate to Rails’ assertions.

be_a_new

  • Available in all specs.
  • Primarily intended for controller specs
object.should be_a_new(Widget)

Passes if the object is a Widget and returns true for new_record?

render_template

  • Delegates to Rails’ assert_template.
  • Available in request, controller, and view specs.

In request and controller specs, apply to the response object:

response.should render_template("new")

In view specs, apply to the view object:

view.should render_template(:partial => "_form", :locals => { :widget => widget } )

redirect_to

  • Delegates to assert_redirect
  • Available in request and controller specs.
response.should redirect_to(widgets_path)

route_to

  • Delegates to Rails’ assert_routing.
  • Available in routing and controller specs.
{ :get => "/widgets" }.should route_to(:controller => "widgets", :action => "index")

be_routable

Passes if the path is recognized by Rails’ routing. This is primarily intended
to be used with should_not to specify routes that should not be routable.

{ :get => "/widgets/1/edit" }.should_not be_routable

Contribute

See http://github.com/rspec/rspec-dev

Also see