麻煩經過rspec的

Question

我想通過這個rspec的

describe "title" do 
it "should capitalize the first letter" do 
    @book.title = "inferno" 
    expect(@book.title).to eq("Inferno") 
end 

it "should capitalize every word" do 
    @book.title = "stuart little" 
    expect(@book.title).to eq("Stuart Little") 
end 

有了這個代碼

class Book 
    attr_accessor :title 

    def initialize(title="") 
    @title = capital(title) 
    end 

    def capital(title) 
    articles = %w(the a an and of in the) 
    new_title = [] 

    title.split.each do |w| 
     articles.include?(w)? new_title << w : new_title << w.capitalize 
     end 

    new_title[0] = new_title[0].capitalize 
    new_title.join(" ") 
    end 

end 

book = Book.new("stuart little") 
puts book.title 

我也得到「精靈鼠小弟」，當我運行的代碼，但我不斷收到錯誤當我通過rspec運行它時。 （例如，它只是作爲「斯圖特小」返回）。

我很困惑爲什麼會發生這種情況，所以我希望有人能爲我揭開一些光。

Answer 1

當您爲new方法分配標題時，只有在將其分配給title=設置方法時，纔會運行capital方法。

我將取代attr_accessor與attr_reader並添加自定義title= setter方法：

class Book 
    attr_reader :title 

    def initialize(title = '') 
    self.title = title # calls the setter below 
    end 

    def title=(title) 
    @title = capital(title) 
    end 

private 

    def capital(string) 
    articles = %w(a an and in of the) 

    words = title.split.map do |word| 
     articles.include?(word) ? word : w.capitalize 
    end 

    words.join(' ').capitalize 
    end 
end