Top Related Projects
Simple one-liner tests for common Rails functionality
Acceptance test framework for web applications
Rails Generators for Cucumber with special support for Capybara and DatabaseCleaner
A library for setting up Ruby objects as test data.
A library for generating fake data such as names, addresses, and phone numbers.
Quick Overview
RSpec-Rails is a testing framework for Ruby on Rails applications. It integrates RSpec, a popular behavior-driven development (BDD) tool for Ruby, with the Rails framework, providing a comprehensive suite of testing tools and helpers specifically designed for Rails projects.
Pros
- Seamless integration with Rails, offering Rails-specific matchers and helpers
- Encourages readable and expressive test code through its descriptive syntax
- Provides a wide range of testing tools, including mocks, stubs, and expectations
- Supports different types of tests: unit, integration, and system tests
Cons
- Steeper learning curve compared to Rails' built-in testing framework (Minitest)
- Can be slower than Minitest for large test suites
- Some developers find the DSL too "magical" or abstract
- Occasional compatibility issues with certain Rails versions or gems
Code Examples
- Testing a model:
RSpec.describe User, type: :model do
it "is valid with valid attributes" do
user = User.new(name: "John Doe", email: "john@example.com")
expect(user).to be_valid
end
it "is not valid without a name" do
user = User.new(email: "john@example.com")
expect(user).to_not be_valid
end
end
- Testing a controller:
RSpec.describe UsersController, type: :controller do
describe "GET #index" do
it "returns a success response" do
get :index
expect(response).to be_successful
end
end
end
- Testing a feature with Capybara:
RSpec.feature "User signs up", type: :feature do
scenario "with valid email and password" do
visit new_user_registration_path
fill_in "Email", with: "user@example.com"
fill_in "Password", with: "password"
fill_in "Password confirmation", with: "password"
click_button "Sign up"
expect(page).to have_text("Welcome! You have signed up successfully.")
end
end
Getting Started
To get started with RSpec-Rails, add it to your Gemfile:
group :development, :test do
gem 'rspec-rails', '~> 5.0'
end
Then, run the following commands:
bundle install
rails generate rspec:install
This will install RSpec and generate the necessary configuration files. You can now start writing tests in the spec
directory of your Rails application.
Competitor Comparisons
Simple one-liner tests for common Rails functionality
Pros of shoulda-matchers
- Provides concise, one-liner matchers for common Rails validations and associations
- Offers a more readable and expressive syntax for testing model attributes
- Integrates seamlessly with RSpec and other testing frameworks
Cons of shoulda-matchers
- Limited to model testing, while rspec-rails covers a broader range of Rails components
- May require additional setup and configuration compared to rspec-rails
- Less frequently updated and maintained compared to rspec-rails
Code Comparison
rspec-rails:
RSpec.describe User, type: :model do
it { should validate_presence_of(:name) }
it { should validate_uniqueness_of(:email) }
it { should have_many(:posts) }
end
shoulda-matchers:
RSpec.describe User, type: :model do
it { is_expected.to validate_presence_of(:name) }
it { is_expected.to validate_uniqueness_of(:email) }
it { is_expected.to have_many(:posts) }
end
Both examples demonstrate similar functionality, but shoulda-matchers provides a more readable syntax with is_expected.to
instead of should
. The shoulda-matchers syntax is often considered more expressive and easier to understand, especially for developers new to testing.
While rspec-rails offers a comprehensive testing solution for Rails applications, shoulda-matchers excels in providing concise and readable matchers for model testing. The choice between the two depends on the specific testing needs and preferences of the development team.
Acceptance test framework for web applications
Pros of Capybara
- Provides a high-level API for simulating user interactions, making it easier to write expressive and readable tests
- Supports multiple drivers (e.g., Selenium, Rack::Test) allowing for flexibility in testing different types of applications
- Offers built-in waiting mechanisms for asynchronous operations, reducing test flakiness
Cons of Capybara
- Limited to testing web applications, while RSpec-Rails can be used for various types of tests (unit, integration, etc.)
- Steeper learning curve for developers new to acceptance testing frameworks
- May require additional setup and configuration compared to RSpec-Rails, especially when using different drivers
Code Comparison
RSpec-Rails:
describe "User authentication" do
it "logs in a user" do
user = create(:user)
visit login_path
fill_in "Email", with: user.email
fill_in "Password", with: user.password
click_button "Log in"
expect(page).to have_content("Welcome back!")
end
end
Capybara:
feature "User authentication" do
scenario "logs in a user" do
user = create(:user)
visit login_path
fill_in "Email", with: user.email
fill_in "Password", with: user.password
click_button "Log in"
expect(page).to have_content("Welcome back!")
end
end
The code examples are similar, but Capybara uses more descriptive language (feature/scenario) for acceptance testing, while RSpec-Rails uses its standard describe/it syntax.
Rails Generators for Cucumber with special support for Capybara and DatabaseCleaner
Pros of cucumber-rails
- More readable for non-technical stakeholders, using plain English descriptions
- Encourages behavior-driven development (BDD) and collaboration between developers and business analysts
- Supports a wide range of programming languages beyond Ruby
Cons of cucumber-rails
- Steeper learning curve due to additional syntax and structure
- Can be slower to execute compared to RSpec tests
- Requires more setup and maintenance for feature files and step definitions
Code Comparison
cucumber-rails:
Feature: User authentication
Scenario: Successful login
Given I am on the login page
When I enter valid credentials
Then I should be logged in
rspec-rails:
RSpec.describe "User authentication" do
it "allows successful login" do
visit login_path
fill_in "Username", with: "user@example.com"
fill_in "Password", with: "password"
click_button "Log In"
expect(page).to have_content("Welcome back!")
end
end
Both frameworks provide powerful testing capabilities for Rails applications. cucumber-rails excels in readability and collaboration, while rspec-rails offers a more concise and faster testing experience. The choice between them often depends on project requirements and team preferences.
A library for setting up Ruby objects as test data.
Pros of Factory Bot
- Focused on creating test data, making it easier to set up complex object graphs
- More flexible and expressive syntax for defining factories
- Supports traits and callbacks for advanced data creation scenarios
Cons of Factory Bot
- Limited to data creation, while RSpec Rails provides a full testing framework
- Steeper learning curve for beginners compared to RSpec's more intuitive syntax
- May encourage overuse of factories, potentially slowing down test suites
Code Comparison
Factory Bot:
FactoryBot.define do
factory :user do
name { "John Doe" }
email { "john@example.com" }
trait :admin do
admin { true }
end
end
end
RSpec Rails:
RSpec.describe User, type: :model do
it "is valid with valid attributes" do
user = User.new(name: "John Doe", email: "john@example.com")
expect(user).to be_valid
end
end
Factory Bot excels at creating test data with a clean, declarative syntax, while RSpec Rails provides a comprehensive testing framework with a focus on behavior description. Factory Bot is often used in conjunction with RSpec Rails to enhance test data creation, combining the strengths of both libraries for more effective testing in Ruby on Rails applications.
A library for generating fake data such as names, addresses, and phone numbers.
Pros of Faker
- Lightweight and focused on generating fake data
- Easier to integrate into non-Rails projects
- Extensive library of data types and locales
Cons of Faker
- Limited to data generation, not a full testing framework
- Less integrated with Rails ecosystem
- Requires additional setup for use in testing scenarios
Code Comparison
RSpec-Rails example:
RSpec.describe User, type: :model do
it "is valid with valid attributes" do
user = User.new(name: "John Doe", email: "john@example.com")
expect(user).to be_valid
end
end
Faker example:
require 'faker'
name = Faker::Name.name
email = Faker::Internet.email
user = User.new(name: name, email: email)
Summary
RSpec-Rails is a comprehensive testing framework for Rails applications, offering a wide range of testing capabilities. Faker, on the other hand, is a library specifically designed for generating fake data, which can be used in various contexts, including testing.
While RSpec-Rails provides a complete testing solution for Rails projects, Faker excels in creating realistic sample data quickly and easily. Faker can be used alongside RSpec-Rails or other testing frameworks to enhance test data generation.
The choice between the two depends on the specific needs of your project. For full Rails application testing, RSpec-Rails is more suitable. For generating fake data in any Ruby project, Faker is the go-to solution.
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rspec-rails
rspec-rails
brings the RSpec testing framework to Ruby on Rails
as a drop-in alternative to its default testing framework, Minitest.
In RSpec, tests are not just scripts that verify your application code. Theyâre also specifications (or specs, for short): detailed explanations of how the application is supposed to behave, expressed in plain English.
According to RSpec Rails new versioning strategy use:
rspec-rails
7.x for Rails 7.x.rspec-rails
6.x for Rails 6.1, 7.0 or 7.1.rspec-rails
5.x for Rails 5.2 or 6.x.rspec-rails
4.x for Rails from 5.x or 6.x.rspec-rails
3.x for Rails earlier than 5.0.rspec-rails
1.x for Rails 2.x.
Installation
IMPORTANT This README / branch refers to the current development build.
See the 7-0-maintenance
branch on Github if you want or require the latest stable release.
-
Add
rspec-rails
to both the:development
and:test
groups of your appâsGemfile
:# Run against this stable release group :development, :test do gem 'rspec-rails', '~> 7.0.0' end # Or, run against the main branch # (requires main-branch versions of all related RSpec libraries) group :development, :test do %w[rspec-core rspec-expectations rspec-mocks rspec-rails rspec-support].each do |lib| gem lib, git: "https://github.com/rspec/#{lib}.git", branch: 'main' end end
(Adding it to the
:development
group is not strictly necessary, but without it, generators and rake tasks must be preceded byRAILS_ENV=test
.) -
Then, in your project directory:
# Download and install $ bundle install # Generate boilerplate configuration files # (check the comments in each generated file for more information) $ rails generate rspec:install create .rspec create spec create spec/spec_helper.rb create spec/rails_helper.rb
Upgrading
If your project is already using an older version of rspec-rails
,
upgrade to the latest version with:
$ bundle update rspec-rails
RSpec follows semantic versioning,
which means that âmajor versionâ upgrades (e.g., 2.x â 3.x)
come with breaking changes.
If youâre upgrading from version 2.x or below,
read the rspec-rails
upgrade notes to find out what to watch out for.
Be sure to check the general RSpec upgrade notes as well.
Usage
Creating boilerplate specs with rails generate
# RSpec hooks into built-in generators
$ rails generate model user
invoke active_record
create db/migrate/20181017040312_create_users.rb
create app/models/user.rb
invoke rspec
create spec/models/user_spec.rb
# RSpec also provides its own spec file generators
$ rails generate rspec:model user
create spec/models/user_spec.rb
# List all RSpec generators
$ rails generate --help | grep rspec
Running specs
# Default: Run all spec files (i.e., those matching spec/**/*_spec.rb)
$ bundle exec rspec
# Run all spec files in a single directory (recursively)
$ bundle exec rspec spec/models
# Run a single spec file
$ bundle exec rspec spec/controllers/accounts_controller_spec.rb
# Run a single example from a spec file (by line number)
$ bundle exec rspec spec/controllers/accounts_controller_spec.rb:8
# See all options for running specs
$ bundle exec rspec --help
Optional: If bundle exec rspec
is too verbose for you,
you can generate a binstub at bin/rspec
and use that instead:
$ bundle binstubs rspec-core
RSpec DSL Basics (or, how do I write a spec?)
In RSpec, application behavior is described first in (almost) plain English, then again in test code, like so:
RSpec.describe 'Post' do #
context 'before publication' do # (almost) plain English
it 'cannot have comments' do #
expect { Post.create.comments.create! }.to raise_error(ActiveRecord::RecordInvalid) # test code
end
end
end
Running rspec
will execute this test code,
and then use the plain-English descriptions
to generate a report of where the application
conforms to (or fails to meet) the spec:
$ rspec --format documentation spec/models/post_spec.rb
Post
before publication
cannot have comments
Failures:
1) Post before publication cannot have comments
Failure/Error: expect { Post.create.comments.create! }.to raise_error(ActiveRecord::RecordInvalid)
expected ActiveRecord::RecordInvalid but nothing was raised
# ./spec/models/post.rb:4:in `block (3 levels) in <top (required)>'
Finished in 0.00527 seconds (files took 0.29657 seconds to load)
1 example, 1 failure
Failed examples:
rspec ./spec/models/post_spec.rb:3 # Post before publication cannot have comments
For an in-depth look at the RSpec DSL, including lots of examples, read the official Cucumber documentation for RSpec Core.
Helpful Rails Matchers
In RSpec, assertions are called expectations,
and every expectation is built around a matcher.
When you expect(a).to eq(b)
, youâre using the eq
matcher.
In addition to the matchers that come standard in RSpec, here are some extras that make it easier to test the various parts of a Rails system:
RSpec matcher | Delegates to | Available in | Notes |
---|---|---|---|
be_a_new | all | primarily intended for controller specs | |
render_template | assert_template | request / controller / view | use with expect(response).to |
redirect_to | assert_redirect | request / controller | use with expect(response).to |
route_to | assert_recognizes | routing / controller | use with expect(...).to route_to |
be_routable | routing / controller | use with expect(...).not_to be_routable | |
have_http_status | request / controller / feature | ||
match_array | all | for comparing arrays of ActiveRecord objects | |
have_been_enqueued | all | requires config: ActiveJob::Base.queue_adapter = :test | |
have_enqueued_job | all | requires config: ActiveJob::Base.queue_adapter = :test |
Follow the links above for examples of how each matcher is used.
What else does RSpec Rails add?
For a comprehensive look at RSpec Railsâ features, read the official Cucumber documentation.
What tests should I write?
RSpec Rails defines ten different types of specs
for testing different parts of a typical Rails application.
Each one inherits from one of Railsâ built-in TestCase
classes,
meaning the helper methods provided by default in Rails tests
are available in RSpec, as well.
Spec type | Corresponding Rails test class |
---|---|
model | |
controller | ActionController::TestCase |
mailer | ActionMailer::TestCase |
job | |
view | ActionView::TestCase |
routing | |
helper | ActionView::TestCase |
request | ActionDispatch::IntegrationTest |
feature | |
system | ActionDispatch::SystemTestCase |
Follow the links above to see examples of each spec type,
or for official Rails API documentation on the given TestCase
class.
Note: This is not a checklist.
Ask a hundred developers how to test an application, and youâll get a hundred different answers.
RSpec Rails provides thoughtfully selected features to encourage good testing practices, but thereâs no ârightâ way to do it. Ultimately, itâs up to you to decide how your test suite will be composed.
When creating a spec file,
assign it a type in the top-level describe
block, like so:
# spec/models/user_spec.rb
RSpec.describe User, type: :model do
...
System specs, feature specs, request specsâwhatâs the difference?
RSpec Rails provides some end-to-end (entire application) testing capability to specify the interaction with the client.
System specs
Also called acceptance tests, browser tests, or end-to-end tests, system specs test the application from the perspective of a human client. The test code walks through a userâs browser interactions,
visit '/login'
fill_in 'Name', with: 'jdoe'
and the expectations revolve around page content.
expect(page).to have_text('Welcome')
Because system specs are a wrapper around Railsâ built-in SystemTestCase
,
theyâre only available on Rails 5.1+.
(Feature specs serve the same purpose, but without this dependency.)
Feature specs
Before Rails introduced system testing facilities, feature specs were the only spec type for end-to-end testing. While the RSpec team now officially recommends system specs instead, feature specs are still fully supported, look basically identical, and work on older versions of Rails.
On the other hand, feature specs require non-trivial configuration to get some important features working, like JavaScript testing or making sure each test runs with a fresh DB state. With system specs, this configuration is provided out-of-the-box.
Like system specs, feature specs require the Capybara gem.
Rails 5.1+ includes it by default as part of system tests,
but if you donât have the luxury of upgrading,
be sure to add it to the :test
group of your Gemfile
first:
group :test do
gem "capybara"
end
Request specs
Request specs are for testing the application from the perspective of a machine client. They begin with an HTTP request and end with the HTTP response, so theyâre faster than feature specs, but do not examine your appâs UI or JavaScript.
Request specs provide a high-level alternative to controller specs. In fact, as of RSpec 3.5, both the Rails and RSpec teams discourage directly testing controllers in favor of functional tests like request specs.
When writing them, try to answer the question, âFor a given HTTP request (verb + path + parameters), what HTTP response should the application return?â
Contributing
Once youâve cloned the repo and set up the environment, you can run the specs and Cucumber features, or submit a pull request.
See Also
RSpec base libraries
- https://github.com/rspec/rspec
- https://github.com/rspec/rspec-core
- https://github.com/rspec/rspec-expectations
- https://github.com/rspec/rspec-mocks
Recommended third-party extensions
-
Capybara (Included by default in Rails 5.1+. Note that additional configuration is required to use the Capybara DSL anywhere other than system specs and feature specs.)
Top Related Projects
Simple one-liner tests for common Rails functionality
Acceptance test framework for web applications
Rails Generators for Cucumber with special support for Capybara and DatabaseCleaner
A library for setting up Ruby objects as test data.
A library for generating fake data such as names, addresses, and phone numbers.
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Introducing Visual Copilot: A new AI model to turn Figma designs to high quality code using your components.
Try Visual Copilot