Iteration B2.

app/models/product.rb

@@ -1,7 +1,7 @@
 class Product < ApplicationRecord
   validates :title, :description, :image_url, :price, presence: true
   validates :price, numericality: {greater_than_or_equal_to: 0.01}
-  validates :title, uniqueness: true
+  validates :title, uniqueness: true, length: { minimum: 5, maximum: 30 }
   validates :image_url, allow_blank: true, format: {
     with: %r{\.(gif|jpg|png)\Z}i,
     message: 'must be URL for GIF, JPG or PNG image.'

test/fixtures/products.yml

@@ -11,3 +11,12 @@ two:
   description: MyText
   image_url: MyString
   price: 9.99
+
+ruby:
+  title: Programming Ruby 1.9
+  description:
+    Ruby is the fastes growing and most exciting dynamic language out
+    there. If you need to get working programs delivered fast, you should
+    add Ruby to your toolbox.
+  price: 49.50
+  image_url: ruby.png

test/models/product_test.rb

@@ -1,7 +1,76 @@
 require 'test_helper'
 
 class ProductTest < ActiveSupport::TestCase
+  # Rails is already doing this! (convention over configuration!)
+  fixtures :products
   # test "the truth" do
   #   assert true
   # end
+
+  test "product attributes must not be empty" do
+    product = Product.new
+    assert product.invalid?
+    assert product.errors[:title].any?
+    assert product.errors[:description].any?
+    assert product.errors[:image_url].any?
+    assert product.errors[:price].any?
+  end
+
+  test "product price be positive" do
+    product = Product.new(title: 'My Book Title',
+                          description: 'My Description.',
+                          image_url: 'image.jpg')
+
+    product.price = -1
+    assert product.invalid?
+    assert_equal ['must be greater than or equal to 0.01'],
+                  product.errors[:price]
+
+    product.price = 0
+    assert product.invalid?
+    assert_equal ['must be greater than or equal to 0.01'],
+                  product.errors[:price]
+
+    product.price = 1
+    assert product.valid?
+  end
+
+  def new_product(image_url)
+    product = Product.new(title: 'My Book Title',
+                          description: 'My Description.',
+                          image_url: image_url,
+                          price: 1)
+  end
+
+  test "image url" do
+    ok = %w{ fred.jpg hans.png paul.Png peter.JPG
+              http://a.b.c.d/images/foo.gif }
+    bad =%w{ fred.doc hans.gif/more }
+
+    ok.each { |name| assert new_product(name).valid? "#{name} shouldn't be invalid" }
+
+    bad.each do |name|
+      assert new_product(name).invalid? "#{name} shouldn't be valid"
+    end
+  end
+
+  test "product is not valid without a unique title - i18n" do
+    product = Product.new(title: products(:ruby).title,
+                          description: 'Foo.',
+                          price: 1,
+                          image_url: "foo.jpg")
+    assert product.invalid?
+    assert_equal [I18n.translate('errors.messages.taken')],
+                  product.errors[:title]
+  end
+
+  test "product is not valid without minimum 5 characters in title" do
+    product = Product.new(title: 'Shrt',
+                          description: 'A short work.',
+                          price: 0.99,
+                          image_url: 'short.jpg')
+    assert product.invalid?
+    assert_equal ['is too short (minimum is 5 characters)'],
+                  product.errors[:title]
+  end
 end