Rails%203%20In%20Action

Deleting projects
The file for this controller test, spec/controllers/projects_controller_spec.rb, was
automatically generated when you ran the controller generator because you have the
rspec-rails gem in your Gemfile. 4 Open this controller spec file and take a look. It
should look like the following listing.
require 'spec_helper'
describe ProjectsController do
end
Listing 4.16 spec/controllers/projects_controller_spec.rb
The spec_helper.rb file it references is located at spec/spec_helper.rb and it, like the
previous examples of spec/spec_helper.rb (in chapter 2), is responsible for setting up
the environment for your tests. This time, however, it already has code, which includes
the Rails environment and the Rails-associated RSpec helpers as well as any file inside
the spec/support directory or its subdirectories.
In this controller spec, you want to test that you get redirected to the Projects page
if you attempt to access a resource that no longer exists. You also want to ensure that a
flash[:alert] is set.
To do all this, you put the following code inside the describe block:
it "displays an error for a missing project" do
get :show, :id => "not-here"
response.should redirect_to(projects_path)
message = "The project you were looking for could not be found."
flash[:alert].should eql(message)
end
The first line inside this RSpec test—more commonly called an example—tells RSpec to
make a GET request to the show action for the ProjectsController. How does it
know which controller should receive the GET request? RSpec infers it from the class
used for the describe block.
In the next line, you tell RSpec that you expect the response to take you back to
the projects_path through a redirect_to call. If it doesn’t, the test fails, and nothing
more in this test is executed: RSpec stops in its tracks.
The final line tells RSpec that you expect the flash[:alert] to contain a useful
messaging explaining the redirection to the index action. 5
To run this spec, use the bin/rspec spec/controllers/projects_controller
_spec.rb command.
It may seem like nothing is happening at first, because RSpec must load the Rails
environment and your application, and loading takes time. The same delay occurs
when you start running a Rails server.
4 The rspec-rails gem automatically generates the file using a Railtie, the code of which can be found at
https://github.com/rspec/rspec-rails/blob/master/lib/rspec-rails.rb.
5 The lines for the flash[:alert] are separated into two lines to accommodate the page width of this book.
You can put it on one line if you like. We won’t yell at you.
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