ruby-on-rails - 类型错误 : wrong argument type String (expected Module)

Question

我有以下代码:

class ProfileLookup < ActiveRecord::Base
  class << self
    ProfileLookup.select("DISTINCT category").map{|c| c.category}.each do |category|
      define_method("available_#{category.pluralize}".to_sym) do
        ProfileLookup.where(category: category).order(:value).all.collect{|g| g.value}
      end
    end
  end
end

基本上包含大量查找数据，按类别拆分。目的是为数据库中的每个类别创建一个方法。通过 Rails 控制台，此代码按预期工作:

ruby-1.9.3@hub :002 > ProfileLookup.available_genders
  ProfileLookup Load (0.6ms)  SELECT "profile_lookups".* FROM "profile_lookups" WHERE "profile_lookups"."category" = 'gender' ORDER BY value
 => ["Female", "Male"] 

但是，我的规范不合格。以下规范:

require "spec_helper"

describe ProfileLookup do

  its(:available_genders).should include("Male")
  its(:available_age_groups).should include("0-17")
  its(:available_interests).should include("Autos & Vehicles")
  its(:available_countries).should include("United States")

end

失败:

Exception encountered: #<TypeError: wrong argument type String (expected Module)>
backtrace:
/Users/fred/code/my_app/spec/models/profile_lookup_spec.rb:5:in `include'

这里有什么问题？

Answer 1

首先，你的its语法是错误的，你应该use the block form :

its(:available_genders) { should include("Male") }

其次，当您描述一个类时，您要匹配的主题是该类的一个实例:

https://www.relishapp.com/rspec/rspec-core/docs/subject/implicit-subject :

If the first argument to the outermost example group is a class, an instance of that class is exposed to each example via the subject() method.

您可以明确说明主题，一切都会奏效:

require "spec_helper"

describe ProfileLookup do

  subject { ProfileLookup }

  its(:available_genders) { should include("Male") }
  its(:available_age_groups) { should include("0-17") }
  its(:available_interests) { should include("Autos & Vehicles") }
  its(:available_countries) { should include("United States") }

end