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, allow_blank: true, 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
Run options: --seed 51296
 
# Running:
 
.F...F.
 
Finished in 0.386701s, 18.1018 runs/s, 25.8598 assertions/s.
 
  1) Failure:
ProductsControllerTest#test_should_update_product [/home/rubys/git/awdwr/edition4/work-226-42/depot/test/controllers/products_controller_test.rb:39]:
Expected response to be a <redirect>, but was <200>
 
 
  2) Failure:
ProductsControllerTest#test_should_create_product [/home/rubys/git/awdwr/edition4/work-226-42/depot/test/controllers/products_controller_test.rb:20]:
"Product.count" didn't change by 1.
Expected: 3
  Actual: 2
 
7 runs, 10 assertions, 2 failures, 0 errors, 0 skips

Solution is simple, provide valid data.

edit test/controllers/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
    patch :update, id: @product, product: @update
    assert_redirected_to product_path(assigns(:product))
  end
 
  # ...
end

Onto the next failure...

rake test
Run options: --seed 6648
 
# Running:
 
.......
 
Finished in 0.314974s, 22.2241 runs/s, 41.2732 assertions/s.
 
7 runs, 13 assertions, 0 failures, 0 errors, 0 skips

Update test data

edit test/fixtures/products.yml
# Read about fixtures at
# http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
 
one:
  title: MyString
  description: MyText
  image_url: lorem.jpg
  price: 9.99
 
two:
  title: MyString
  description: MyText
  image_url: lorem.jpg
  price: 9.99

Tests now pass again :-)

rake test
Run options: --seed 19642
 
# Running:
 
.......
 
Finished in 0.283363s, 24.7033 runs/s, 45.8775 assertions/s.
 
7 runs, 13 assertions, 0 failures, 0 errors, 0 skips

7.2 Iteration B2: Unit Testing 6.3 Playtime