factory_girl和sprintf

Question

首先，我对Ruby很新，虽然我有很强的Java背景（没有帮助:)。我创建了我的第一个Rails应用程序，我正在使用FactoryGirl。我遇到了一些奇怪的东西（对我来说），我无法弄清楚为什么它会像这样。

在工厂内使用sprintf（参见上一个测试）会引发以下错误：

Failures:
  1) Test raises an ArgumentError
     Failure/Error: sprintf('Product %05d', n)
     ArgumentError:
       wrong number of arguments (3 for 2)
     # ./spec/models/fg_spec.rb:6:in `fff'
     # ./spec/models/fg_spec.rb:31:in `block (3 levels) in <top (required)>'
     # ./spec/models/fg_spec.rb:62:in `block (2 levels) in <top (required)>'

以下是演示此行为的完整规范：

def fff(n)
    sprintf('WWW Product %05d', n)
end

b1 = proc { |n| fff(n) }
b2 = proc { |n| sprintf('WWW Product %05d', n) }

FactoryGirl.define do

    factory :product1, :class => Product do
        sequence(:name) { |n| 'Product %05d' % "#{n}" }
    end

    factory :product2, :class => Product do
        sequence(:name) { |n| sprintf('WWW Product %05d', n) }
    end

    factory :product3, :class => Product do
        sequence(:name, 1, &b1)
    end

    factory :product4, :class => Product do
        sequence(:name, 1, &b2)
    end

    factory :product5, :class => Product do
        sequence(:name) { |n| fff(n) }
    end

end

describe Test do

    it "works with %" do
        p = Factory.create(:product1)
        puts p.inspect
    end

    it "does not work with sprintf" do
        expect { Factory.create(:product2) }.to raise_error(ArgumentError)
    end

    it "works with a block with a function" do
        p = Factory.create(:product3)
        puts p.inspect
    end

    it "works with a block with sprintf" do
        p = Factory.create(:product4)
        puts p.inspect
    end

    it "does not work with a function with sprintf" do
        expect { Factory.create(:product5) }.to raise_error(ArgumentError)
    end

end

当然我可以使用％表示法，但我对此非常好奇。

谢谢，

大卫

Answer 1

您需要使用其完整命名空间访问sprintf：

b2 = proc { |n| Kernel.sprintf('WWW Product %05d', n) }

这是因为有问题的代码是在未定义sprintf的不同上下文中调用的。