Agile Web Development with Rails, Edition 5

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 < ApplicationRecord
  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 < ApplicationRecord
  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 :-(

rails test
Run options: --seed 31976
 
# Running:
 
..F
 
Failure:
ProductsControllerTest#test_should_create_product [/home/rubys/git/awdwr/edition4/work-233-50/depot/test/controllers/products_controller_test.rb:19]:
"Product.count" didn't change by 1.
Expected: 3
  Actual: 2
 
bin/rails test test/controllers/products_controller_test.rb:18
 
...F
 
Failure:
ProductsControllerTest#test_should_update_product [/home/rubys/git/awdwr/edition4/work-233-50/depot/test/controllers/products_controller_test.rb:38]:
Expected response to be a <3XX: redirect>, but was a <200: OK>
 
bin/rails test test/controllers/products_controller_test.rb:36
 
 
 
Finished in 0.608478s, 11.5041 runs/s, 13.1476 assertions/s.
 
7 runs, 8 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 < ActionDispatch::IntegrationTest
  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 products_url
    assert_response :success
  end
 
  test "should get new" do
    get new_product_url
    assert_response :success
  end
 
  test "should create product" do
    assert_difference('Product.count') do
      post products_url, params: { product: @update }
    end
 
    assert_redirected_to product_url(Product.last)
  end
 
  # ...
  test "should update product" do
    patch product_url(@product), params: { product: @update }
    assert_redirected_to product_url(@product)
  end
 
  # ...
end

Onto the next failure...

rails test
Run options: --seed 25123
 
# Running:
 
.......
 
Finished in 0.492874s, 14.2024 runs/s, 18.2602 assertions/s.
 
7 runs, 9 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 :-)

rails test
Run options: --seed 19709
 
# Running:
 
.......
 
Finished in 0.483876s, 14.4665 runs/s, 18.5998 assertions/s.
 
7 runs, 9 assertions, 0 failures, 0 errors, 0 skips

7.2 Iteration B2: Unit Testing 6.3 Playtime