Add a controller test for UserLimericksController#index

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In this part, we will make a controller test for the UserLimericksController#index controller action, which has some key differences from the LimericksController#index action we wrote a test for earlier.

• UserLimericksController#index displays only the limericks authored by one particular user.
• User authentication is required to access the UserLimericksController#index action.

These differences change how the controller test must be written.

Tasks

• Inspect the UserLimericksController#index controller action.
• Add a controller test for the index action.
• Run the controller test

Inspect the UserLimericksController#index controller action

Recall that we must (1) find the route for this controller action and (2) determine if user authentication is required to access the action.

• Open the config/routes.rb file, and locate the route that calls this index action. You should find this route:

  get 'users/:user_id/limericks', to: 'user_limericks#index', as: 'user_limericks'

• Note that, as per the as part of this route, the URL helper will be named user_limericks_url.

• Note that the URI pattern ('users/:user_id/limericks') contains a parameter (:user_id), so the URL helper will need to be passed an argument for that parameter (e.g., user_limericks_url(current_user)).

• Open the app/controllers/user_limericks_controller.rb file in VS Code, and inspect the UserLimericksController class defined within:

class UserLimericksController < ApplicationController

  before_action :authenticate_user!

  def index
    @user = User.find(params[:user_id])
    @limericks = @user.limericks.reverse_order
    render :index
  end

end

• Note that the before_action requires that the user be authenticated in order to access all the actions in this controller, including the index action.

Add a controller test for the index action

• Open the controller test file test/controller/user_limericks_controller_test.rb in VS Code. Since we have yet to edit this file, it contains only the commented-out test case generated by default, "the truth".

require "test_helper"

class UserLimericksControllerTest < ActionDispatch::IntegrationTest
  # test "the truth" do
  #   assert true
  # end
end

• Import a Devise mixin module into the controller test class, so that we can call Devise helpers when writing our test cases.

class UserLimericksControllerTest < ActionDispatch::IntegrationTest
  include Devise::Test::IntegrationHelpers

  # test "the truth" do
  #   assert true
  # end
end

• Uncomment the test case, and rename it as "should get index".

  test "should get index" do
    assert true
  end

• Note that it is OK that this test case has the same name as the one we made earlier because the test cases are members of different controller test classes.

• Arrange. Make the following changes to the test case to prepare the system to run the index action.

  • Retrieve the User fixture one from the database. The limericks for which this user is the author will be the focus of this test case. Recall from the fixture code that this user authored two limericks.
  • Store the size of this user’s collection of limericks in a variable limericks_size.
  • Sign in the user using the sign_in Devise helper, so the test will be able to execute the index method without error.

  test "should get index" do
    user = users(:one)
    limericks_size = user.limericks.size
    sign_in user
  end

• Note that the fixture methods, such as users, can be used to retrieve an individual fixture by passing a symbol with the name of the fixture, such as :one.

• Note that we must capture the size of this user’s set of limericks (rather than all the limericks stored in the database) as only this user’s limericks will be displayed on the page.

• Act. Use the get command to simulate an HTTP GET request with the URL for the index page as follows.

  test "should get index" do
    user = users(:one)
    limericks_size = user.limericks.size
    sign_in user
    get user_limericks_url(user)
  end

• Assert. Like before, replace the assert true call with calls to these two assertions:
  • assert_response: checks that the HTTP response produced by the app has a success code (a 2xx status code, like 200 OK).
  • assert_select: checks that the correct number of cards were rendered on the page.

  test "should get index" do
    user = users(:one)
    limericks_size = user.limericks.size
    sign_in user
    get user_limericks_url(user)
    assert_response :success
    assert_select 'div.card', limericks_size
  end

Run the controller test

• As before, run the following command to run all test cases defined in the project.

rails test -v

• Inspect the output, which should look like the following.

Running 2 tests in a single process (parallelization threshold is 50)
Run options: -v --seed 18500

# Running:

LimericksControllerTest#test_should_get_index = 2.37 s = .
UserLimericksControllerTest#test_should_get_index = 0.02 s = .

Finished in 2.398942s, 0.8337 runs/s, 1.6674 assertions/s.
2 runs, 4 assertions, 0 failures, 0 errors, 0 skips

• Note that UserLimericksControllerTest#test_should_get_index is now included in the list of test cases that ran.
  • 2 total test cases ran: this test and the previous one.
  • 4 assertions were checked: 2 from this test and 2 from the previous one.
  • 0 test assertions failed (“failures”) and 0 system errors occurred (“errors”).

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