11.1 Iteration F1: Moving the Cart 10.3 Iteration E3: Finishing the Cart
Once again, get the tests working, and add tests for the smarter cart.
See that the tests fail.
rake test
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader
Started
.......
Finished in 0.405601 seconds.
7 tests, 25 assertions, 0 failures, 0 errors
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader
Started
.F....................
Finished in 0.818704 seconds.
1) Failure:
test_should_destroy_cart(CartsControllerTest) [test/functional/carts_controller_test.rb:43]:
"Cart.count" didn't change by -1.
<1> expected but was
<2>.
22 tests, 34 assertions, 1 failures, 0 errors
Errors running test:functionals!
Substitute names of products and carts for numbers
edit test/fixtures/line_items.yml
# Read about fixtures at http://ar.rubyonrails.org/classes/Fixtures.html
one:
product: ruby
cart: one
two:
product: ruby
cart: one
Update expected target of redirect: Cart#destroy.
edit test/functional/carts_controller_test.rb
test "should destroy cart" do
assert_difference('Cart.count', -1) do
session[:cart_id] = @cart.id
delete :destroy, :id => @cart.to_param
end
assert_redirected_to store_path
end
Test both unique and duplicate products.
edit test/unit/cart_test.rb
require 'test_helper'
class CartTest < ActiveSupport::TestCase
test "add unique products" do
cart = Cart.create
book_one = products(:one)
book_two = products(:two)
cart.add_product(book_one.id).save!
cart.add_product(book_two.id).save!
assert_equal 2, cart.line_items.size
assert_equal book_one.price + book_two.price, cart.total_price
end
test "add_duplicate_product" do
cart = Cart.create
ruby_book = products(:ruby)
cart.add_product(ruby_book.id).save!
cart.add_product(ruby_book.id).save!
assert_equal 2*book_one.price, cart.total_price
assert_equal 1, cart.line_items.size
assert_equal 2, cart.line_items[0].quantity
end
end
ruby -I test test/unit/cart_test.rb
Loaded suite test/unit/cart_test
Started
E.
Finished in 0.283719 seconds.
1) Error:
test_add_duplicate_product(CartTest):
NameError: undefined local variable or method `book_one' for #<CartTest:0x7fae9a8472b8>
test/unit/cart_test.rb:24:in `test_add_duplicate_product'
2 tests, 2 assertions, 0 failures, 1 errors
Refactor.
edit test/unit/cart_test.rb
require 'test_helper'
class CartTest < ActiveSupport::TestCase
def setup
@cart = Cart.create
@book_one = products(:ruby)
@book_two = products(:two)
end
test "add unique products" do
@cart.add_product(@book_one.id).save!
@cart.add_product(@book_two.id).save!
assert_equal 2, @cart.line_items.size
assert_equal @book_one.price + @book_two.price, @cart.total_price
end
test "add duplicate product" do
@cart.add_product(@book_one.id).save!
@cart.add_product(@book_one.id).save!
assert_equal 2*@book_one.price, @cart.total_price
assert_equal 1, @cart.line_items.size
assert_equal 2, @cart.line_items[0].quantity
end
end
ruby -I test test/unit/cart_test.rb
Loaded suite test/unit/cart_test
Started
..
Finished in 0.353828 seconds.
2 tests, 5 assertions, 0 failures, 0 errors
Verify that the tests pass.
rake test
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader
Started
........
Finished in 0.460853 seconds.
8 tests, 29 assertions, 0 failures, 0 errors
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader
Started
......................
Finished in 0.847638 seconds.
22 tests, 35 assertions, 0 failures, 0 errors
Add a test ensuring that non-empty carts can't be deleted.
edit test/functional/products_controller_test.rb
test "can't delete product in cart" do
assert_difference('Product.count', 0) do
delete :destroy, :id => products(:ruby).to_param
end
assert_redirected_to products_path
end
test "should destroy product" do
assert_difference('Product.count', -1) do
delete :destroy, :id => @product.to_param
end
assert_redirected_to products_path
end
Now the tests should pass.
rake test
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader
Started
........
Finished in 0.459348 seconds.
8 tests, 29 assertions, 0 failures, 0 errors
Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader
Started
.......................
Finished in 0.931106 seconds.
23 tests, 37 assertions, 0 failures, 0 errors
Add price to line item
rails generate migration add_price_to_line_item price:decimal
invoke active_record
create db/migrate/20120629163239_add_price_to_line_item.rb
edit db/migrate/20120629163239_add_price_to_line_item.rb
class AddPriceToLineItem < ActiveRecord::Migration
def self.up
add_column :line_items, :price, :decimal
LineItem.all.each do |li|
li.price = li.product.price
end
end
def self.down
remove_column :line_items, :price
end
end
rake db:migrate
mv 20120629163239_add_price_to_line_item.rb 20110711000006_add_price_to_line_item.rb
== AddPriceToLineItem: migrating =============================================
-- add_column(:line_items, :price, :decimal)
-> 0.0014s
== AddPriceToLineItem: migrated (0.0694s) ====================================
edit app/models/cart.rb
class Cart < ActiveRecord::Base
has_many :line_items, :dependent => :destroy
def add_product(product_id)
current_item = line_items.find_by_product_id(product_id)
if current_item
current_item.quantity += 1
else
current_item = line_items.build(:product_id => product_id)
current_item.price = current_item.product.price
end
current_item
end
def total_price
line_items.to_a.sum { |item| item.total_price }
end
end
git commit -a -m "Adding a Cart"
[master 8046ad0] Adding a Cart
6 files changed, 95 insertions(+), 11 deletions(-)
git tag iteration-d
11.1 Iteration F1: Moving the Cart 10.3 Iteration E3: Finishing the Cart