Agile Web Development with Rails, Edition 4

7.2 Iteration B2: Unit Testing 6.3 Playtime

7.1 Iteration B1: Validation and Unit Testing

Augment the model with a few vailidity checks.

Various validations: required, numeric, positive, and unique

edit app/models/product.rb
class Product < ActiveRecord::Base
  validates :title, :description, :image_url, :presence => true
  validates :price, :numericality => {:greater_than_or_equal_to => 0.01}
  validates :title, :uniqueness => true
  validates :image_url, :allow_blank => true, :format => {
    :with    => %r{\.(gif|jpg|png)\Z}i,
    :message => 'must be a URL for GIF, JPG or PNG image.'
  }
end

Demonstrate failures.

get /products/new

New product





Back
post /products

New product

4 errors prohibited this product from being saved:

  • Title can't be blank
  • Description can't be blank
  • Image url can't be blank
  • Price must be greater than or equal to 0.01




Back

Demonstrate more failures.

get /products/new

New product





Back
post /products

New product

1 error prohibited this product from being saved:

  • Price is not a number




Back
edit app/models/product.rb
class Product < ActiveRecord::Base
  validates :title, :description, :image_url, :presence => true
  validates :price, :numericality => {:greater_than_or_equal_to => 0.01}
  validates :title, :uniqueness => true
  validates :image_url, :format => {
    :with    => %r{\.(gif|jpg|png)\Z}i,
    :message => 'must be a URL for GIF, JPG or PNG image.'
  }
end

Now run the tests... and watch them fail :-(

rake test
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p374/gems/rake-10.1.1/lib/rake/rake_test_loader
Started
.
Finished in 0.163057 seconds.
 
1 tests, 1 assertions, 0 failures, 0 errors
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p374/gems/rake-10.1.1/lib/rake/rake_test_loader
Started
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
F.....F
Finished in 0.553359 seconds.
 
  1) Failure:
test_should_create_product(ProductsControllerTest) [test/functional/products_controller_test.rb:20]:
"Product.count" didn't change by 1.
<3> expected but was
<2>.
 
  2) Failure:
test_should_update_product(ProductsControllerTest) [test/functional/products_controller_test.rb:39]:
Expected response to be a <:redirect>, but was <200>
 
7 tests, 9 assertions, 2 failures, 0 errors
Errors running test:functionals!

Solution is simple, provide valid data.

edit test/functional/products_controller_test.rb
require 'test_helper'
 
class ProductsControllerTest < ActionController::TestCase
  setup do
    @product = products(:one)
    @update = {
      :title       => 'Lorem Ipsum',
      :description => 'Wibbles are fun!',
      :image_url   => 'lorem.jpg',
      :price       => 19.95
    }
  end
 
  test "should get index" do
    get :index
    assert_response :success
    assert_not_nil assigns(:products)
  end
 
  test "should get new" do
    get :new
    assert_response :success
  end
 
  test "should create product" do
    assert_difference('Product.count') do
      post :create, :product => @update
    end
 
    assert_redirected_to product_path(assigns(:product))
  end
 
  # ...
  test "should update product" do
    put :update, :id => @product.to_param, :product => @update
    assert_redirected_to product_path(assigns(:product))
  end
 
  # ...
end

Tests now pass again :-)

rake test
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p374/gems/rake-10.1.1/lib/rake/rake_test_loader
Started
.
Finished in 0.164459 seconds.
 
1 tests, 1 assertions, 0 failures, 0 errors
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p374/gems/rake-10.1.1/lib/rake/rake_test_loader
Started
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
.......
Finished in 0.263317 seconds.
 
7 tests, 10 assertions, 0 failures, 0 errors

7.2 Iteration B2: Unit Testing 6.3 Playtime