如何编写插入rspec示例的方法？

In a bunch of rspec rails unit specifications I do something like:

在一堆rspec rails单元规格中,我做了类似的事情:

describe Foo do
  [:bar, :baz].each do |a|
    it "should have many #{a}" do
      Foo.should have_many(a)
    end
  end
end

For cleaner code I'd rather do something like:

为了更清洁的代码,我宁愿做类似的事情:

describe Foo do
  spec_has_many Foo, :bar, :baz
end

So how do I write a helper method like spec_has_many() for inserting DSL code like rspec's it() method? If it were for an ordinary instance method I'd do something like:

那么如何编写像spec_has_many()这样的辅助方法来插入DSL代码,如rspec的it()方法?如果它是一个普通的实例方法,我会做类似的事情:

def spec_has_many(model, *args)
  args.each do |a|
    define_method("it_should_have_many_#{a}") do
      model.should have_many(a)
    end
  end
end

What would be the equivalent for defining rspec examples?

什么是定义rspec示例的等价物?

1 个解决方案

#1

Ok, this took some messing around, but I think I got it working. It's a bit of metaprogramming hackery, and I personally would just use the first thing you described, but it's what you wanted :P

好吧,这需要一些麻烦,但我认为我得到了它的工作。这是一个元编程的hackery,我个人会使用你描述的第一件事,但这是你想要的:P

module ExampleMacros
  def self.included(base)
    base.extend(ClassMethods)
  end

  module ClassMethods
    # This will be available as a "Class Macro" in the included class
    def should_have_many(*args)
      args.each do |a|
        # Runs the 'it' block in the context of the current instance
        instance_eval do
          # This is just normal RSpec code at this point
          it "should have_many #{a.to_s}" do
            subject.should have_many(a)
          end
        end
      end
    end
  end
end

describe Foo do
  # Include the module which will define the should_have_many method
  # Can be done automatically in RSpec configuration (see below)
  include ExampleMacros

  # This may or may not be required, but the should_have_many method expects
  # subject to be defined (which it is by default, but this just makes sure
  # it's what we expect)
  subject { Foo }

  # And off we go. Note that you don't need to pass it a model
  should_have_many :a, :b
end

My specs fail because Foo doesn't have a has_many? method, but both tests run, so it should work.

我的规格失败了,因为Foo没有has_many?方法,但两个测试运行,所以它应该工作。

You can define (and rename) the ExampleMacros module in your spec_helper.rb file and it will be available for inclusion. You want to call include ExampleMacros in your describe blocks (and not any others).

您可以在spec_helper.rb文件中定义(并重命名)ExampleMacros模块,它可以包含在内。您想在描述块(而不是其他任何块)中调用包含ExampleMacros。

To make all of your specs include the module automatically, configure RSpec like so:

要使所有规范自动包含模块,请像这样配置RSpec:

# RSpec 2.0.0
RSpec.configure do |c|
  c.include ExampleMacros
end

#1