ruby-on-rails-3 - Rspec/Rails 和测试 validates_uniquess_of 范围

Question

这是我的测试代码:

require 'spec_helper'

describe Classroom, focus: true do

  let(:user) { build_stubbed(:user) }

  describe "associations" do
    it { should belong_to(:user) }
  end

  describe "validations" do
    it { should validate_presence_of(:user) }
    it { should validate_uniqueness_of(:name).scoped_to(:user_id) }

    context "should create a unique classroom per user" do

      before(:each) do
        @class = build_stubbed(:classroom, name: "Hello World", user: user)
        @class2 = build_stubbed(:classroom, name: "Hello World", user: user)
      end

      it "should not create the second classroom" do
        @class2.should have(1).errors_on(:name)
      end
    end
  end

  describe "instance methods" do

    before(:each) do
      @classroom = build_stubbed(:classroom)
    end

    describe "archive!" do

      context "when a classroom is active" do
        it "should mark classroom as inactive" do
          @classroom.stub(:archive!)
          @classroom.active.eql? false
        end
      end

    end

  end

end

这是我的类模型:

class Classroom < ActiveRecord::Base
  attr_accessible :user, :name

  belongs_to :user

  validates :user, presence: true
  validates_uniqueness_of :name, scope: :user_id, message: "already exists"

  def archive!
    update_attribute(:active, false)
  end
end

当我运行测试时，我收到以下错误:

1) Classroom validations 
     Failure/Error: it { should validate_uniqueness_of(:name).scoped_to(:user_id) }
       Expected errors to include "has already been taken" when name is set to "arbitrary_string", got errors: ["user can't be blank (nil)", "name already exists (\"arbitrary_string\")"]
     # ./spec/models/classroom_spec.rb:13:in `block (3 levels) in <top (required)>'

  2) Classroom validations should create a unique classroom per user should not create the second classroom
     Failure/Error: @classroom2.should have(1).errors_on(:name)
       expected 1 errors on :name, got 0
     # ./spec/models/classroom_spec.rb:24:in `block (4 levels) in <top (required)>'

我对编写测试相当陌生(尤其是使用 Rspec)。只是想找人就我做错了什么给我一些建议。

Answer 1

1. 第一次验证失败 :
   在您的模型中，您已经覆盖了 rspec 为唯一性验证生成的默认消息。因此，在测试此类验证时，您必须使用 shoulda 的 'with_message' 选项。所以测试应该像
   “它{应该 validate_uniqueness_of(:name).scoped_to(:user_id) }.with_message('already exists')”

2. 第二次验证失败:
   当您像第二个示例一样自己编写唯一性验证规范时，您必须创建一个已经存在于数据库中的记录，并使用类似的参数构建第二个记录。那么这条重复的记录将无效，并且会出现预期的错误。
   所以在 before(:each) block 中，将第一条@classroom 记录保存在数据库中，而不是仅仅构建它