Ruby on Rails: testing – Notes and Random Stuff

$ rake db:test:prepare

Ensures that the db in development environment is propagated to the test environment.

To have pending RSpec tests, you do the following:
require ‘spec_helper’
describe User do
pending “add some examples to (or delete) #{__FILE__}”
end
…

If you want to prepare data prior to testing:
before(:each) do
@attr = { :name => “Example User”, :email => “user@example.com” }
end

When checking for validity of records, you can do it as:
no_name_user.should_not be_valid
or
no_name_user.valid?.should_not == true

With the code below, we are testing that a certain object has a certain attribute (with responds_to):
it “should have an encrypted password attribute” do
@user.should respond_to(:encrypted_password)
end

Adding factories to create testing objects can save a lot of time, there is a gem that can be added to your Gemfile, in the test environment to do this:
group :test do
. . .
gem ‘factory_girl_rails’, ‘1.0’
end

Once the gem is install (bundle install), you can create the following file:
spec/factories.rb
And here’s a sample content:
# By using the symbol ‘:user’, we get Factory Girl to simulate the User model.
Factory.define :user do |user|
user.name “Michael Hartl”
user.email “mhartl@example.com”
user.password “foobar”
user.password_confirmation “foobar”
end

So now, factory objects of the order :user can be created for testing purposes as follows:
@user = Factory(:user)

Here’s an example of a Factory that contains associations between two different objects:
# By using the symbol ‘:user’, we get Factory Girl to simulate the User model.
Factory.define :user do |user|
user.name “Michael Hartl”
user.email “mhartl@example.com”
user.password “foobar”
user.password_confirmation “foobar”
end

Factory.sequence :email do |n|
“person-#{n}@example.com”
end

Factory.define :micropost do |micropost|
micropost.content “Foo bar”
micropost.association :user
end

If you want to clear the test database of any user data still hanging there, use:
$ rake db:reset

Rails 4 update

Example of a model test (creating an article). The test resides in /test/models/

require 'test_helper'

class ArticleTest < ActiveSupport::TestCase
  test "should create article" do
    article = Article.new

    article.user  = users(:eugene)
    article.title = "Test article"
    article.body  = "Test body"

    assert article.save
  end
end

Some of the most used available assertions:

assert(boolean, message=nil)
assert_block(message="assert_block failed.") do ... end
assert_equal(expected, actual, message=nil)
assert_in_delta(expected_float, actual_float, delta, message="")
assert_instance_of(klass, object, message="")
assert_kind_of(klass, object, message="")
assert_match(pattern, string, message="")
assert_nil(object, message="")
assert_no_match(regexp, string, message="")
assert_not_equal(expected, actual, message="")
assert_not_nil(object, message="")
assert_not_same(expected, actual, message="")
assert_nothing_raised(*args) do ... end
assert_nothing_thrown(message="") do ... end
assert_operator(object1, operator, object2, message="")
assert_raise(expected_exception_klass, message="") do ... end
assert_respond_to(object, method, message="")
assert_same(expected, actual, message="")
assert_send(send_array, message="")
assert_throws(expected_symbol, message="") do ... end

To run it:

$ rake test:models

In order to generate a template for integration testing:

$rails generate test_unit:integration UserStories

To run that particular test:
$ruby -Itest test/integration/user_stories_test.rb

And, to run the full test suite:
$rake

$bundle exec rspec [name of the spec you want to run, optional]

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