Add step definitions for removing book

Similarly, we are going to add "remove_book.rb" under "features/step_definations".

cd step_definations

touch remove_book.rb

Then edit it to contain following content:

# encoding: utf-8
When /^I remove the book from my shopping cart$/ do
    openShoppingCart
    removeTheFirstItem
end

Then /^I should not see the book in my shopping cart$/ do
    verifyItemRemovedFromShoppingCart
    verifyItemRemovedNotShownInShoppingCart
end
def openShoppingCart
    clickElementBy("id","nav-cart")
end
def removeTheFirstItem
    sleep (10) #it's better to wait for js or AJAX executed complete, but there is not a general way we can follow in industry
    clickElementBy("xpath","//span[@class=\"a-declarative\"]/input")
end
def verifyItemRemovedFromShoppingCart
    confirm=findElementBy("class", "a-size-base")
    confirm.text.include?("was removed from Shopping Cart")
end
def verifyItemRemovedNotShownInShoppingCart
    book=findElementBy("xpath", "//span[@class=\"a-size-medium a-text-bold\"]")
    book.text.should == "Subtotal (0 item): $0.00"
end