Controller tests in Ruby on Rails - Mini Project: Build & Apply

Basic Controller Tests in Rails

📖 Scenario: You are building a simple blog application in Rails. You want to make sure your PostsController works correctly by writing tests for its main actions.

🎯 Goal: Write controller tests for the PostsController to check that the index and show actions respond successfully and render the correct templates.

📋 What You'll Learn

Create a test file for PostsController in test/controllers/posts_controller_test.rb

Write a test for the index action that checks for a successful HTTP response

Write a test for the show action that checks for a successful HTTP response

Use Rails built-in test framework syntax

💡 Why This Matters

🌍 Real World

Controller tests help ensure that your web app's pages load correctly and respond as expected before you deploy your app.

💼 Career

Writing controller tests is a common task for Rails developers to maintain code quality and prevent bugs in web applications.

1

Setup test data

Create a Post record in the test database with title set to 'Test Post' and body set to 'This is a test post.'. Write this inside the setup method of PostsControllerTest.

Ruby on Rails

require "test_helper"

class PostsControllerTest < ActionDispatch::IntegrationTest
  def setup
    # Create a Post record with title 'Test Post' and body 'This is a test post.'
    # Your code here
  end
end

Need a hint?

Use Post.create inside the setup method to create the test post.

2

Test the index action response

Add a test method called test_index_should_get_success that sends a get request to posts_url and asserts the response is successful using assert_response :success.

Ruby on Rails

require "test_helper"

class PostsControllerTest < ActionDispatch::IntegrationTest
  def setup
    @post = Post.create(title: "Test Post", body: "This is a test post.")
  end

  # Add a test for index action response
  # Your code here
end

Need a hint?

Use get posts_url and then assert_response :success inside the test method.

3

Test the show action response

Add a test method called test_show_should_get_success that sends a get request to post_url(@post) and asserts the response is successful using assert_response :success.

Ruby on Rails

require "test_helper"

class PostsControllerTest < ActionDispatch::IntegrationTest
  def setup
    @post = Post.create(title: "Test Post", body: "This is a test post.")
  end

  def test_index_should_get_success
    get posts_url
    assert_response :success
  end

  # Add a test for show action response
  # Your code here
end

Need a hint?

Use get post_url(@post) and assert_response :success inside the test method.

4

Complete the test file

Ensure the test file test/controllers/posts_controller_test.rb includes the setup method and both test methods test_index_should_get_success and test_show_should_get_success inside the PostsControllerTest class.

Ruby on Rails

require "test_helper"

class PostsControllerTest < ActionDispatch::IntegrationTest
  def setup
    @post = Post.create(title: "Test Post", body: "This is a test post.")
  end

  def test_index_should_get_success
    get posts_url
    assert_response :success
  end

  def test_show_should_get_success
    get post_url(@post)
    assert_response :success
  end

  # Confirm the class is closed properly
  # Your code here
end

Need a hint?

Make sure the class and methods are properly closed with end.