Create base page to contains all methods

Let's create a base page first: touch base_page.rb

We will edit the "base_page.rb" and can simple copy all the methods start from def openSite (site) in the "buy_book.rb" and def openShoppingCart in "remove_book.rb" into it. It should contains following content:

# encoding: utf-8
def openSite (site)
    @driver.get site
end

def loginAs (username,password)
    clickElementBy("id", "nav-signin-text")
    inputToElementWith("id", "ap_email", username)
    inputToElementWith("id", "ap_password", password)
    clickElementBy("id","signInSubmit-input")
end
def searchByKeyword (keyword)
    searchKeyword=findElementBy("id","twotabsearchtextbox")
    searchKeyword.clear
    searchKeyword.send_keys keyword
    clickElementBy("class", "nav-submit-input")
end
def openTheFirstItemInSearchResult
    clickElementBy("xpath", "//div[@id=\"result_0\"]//span[@class=\"lrg bold\"]")
end
def getCurrentItemTitle
    @bookTitle=findElementBy("id", "productTitle").text
end
def addToWishList
    clickElementBy("id","add-to-wishlist-button-submit")
end
def openWishList
    clickElementBy("class","w-button-inner")
end
def openShoppingCart
    clickElementBy("id","nav-cart")
end
def addToShoppingCart
    clickElementBy("name", "submit.add-to-cart")
end
def addToShoppingCartFromWishList
    clickElementBy("xpath", "//a[@class=\"a-button-text a-declarative\"]")
end
def verifyItemAddedToShoppingCart
    confirm=findElementBy("id", "confirm-text")
    confirm.text.include?("1 item added to Cart")
end
def verifyItemAddedShownInShoppingCart
    book=findElementBy("xpath", "//div[@class=\"a-row a-size-base word-break\"]/a")
    book.attribute("title").should == @bookTitle
    @driver.save_screenshot ("screenshot.png")
end
def clickElementBy (type, value)
    findElementBy(type, value).click
end
def inputToElementWith (type, value, input)
    inputElement=findElementBy(type, value)
    inputElement.clear
    inputElement.send_keys input
end
def findElementBy (type, value)
    if type=="class"
        @element=@driver.find_element :class => value
    elsif type=="css"
        @element=@driver.find_element :css => value
    elsif type=="id"
        @element=@driver.find_element :id => value
    elsif type=="link"
        @element=@driver.find_element :link => value
    elsif type=="name"
        @element=@driver.find_element :name => value
    elsif type=="partial_link"
        @element=@driver.find_element :partial_link_text => value
    elsif type=="tag"
        @element=@driver.find_element :tag_name => value
    elsif type=="xpath"
        @element=@driver.find_element :xpath => value
    else
        p "incorrect selector type"
    end
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

Ruby will load the pages according to their name ascendingly, so it's better to name your base page to be loaded first.

Please DO remember to delete the methods we copied in "buy_book.rb" and "remove_book.rb". they should look like: