Ruby on rails 测试此帖子和评论模型之间的关联？

在前面的问题中，我问了如何为

Post

和用户

model

构建测试。现在我想测试第三个模型，名为

Comment

schema.rb:

  create_table "posts", :force => true do |t|
    t.string   "title"
    t.string   "content"
    t.integer  "user_id"
    t.datetime "created_at",                               :null => false
    t.datetime "updated_at",                               :null => false
    t.integer  "comments_count",        :default => 0,     :null => false
    t.datetime "published_at"
    t.boolean  "draft",                 :default => false
  end

  create_table "comments", :force => true do |t|
    t.text     "content"
    t.integer  "post_id"
    t.integer  "user_id"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

class Comment < ActiveRecord::Base
  attr_accessible :content, :user_id

  belongs_to :post, :counter_cache => true
  belongs_to :user
end

FactoryGirl.define do
  factory :user do
    username     "Michael Hartl"
    email    "michael@example.com"
    password "foobar"
    password_confirmation "foobar"
  end
end

FactoryGirl.define do
  factory :post do
    title     "Sample Title"
    content    "Sample Content"
    published_at Time.now()
    comments_count 0
    draft false
    association :user
  end
end

require 'spec_helper'

describe Post do
  let(:post) { FactoryGirl.create(:post) }

  subject { post }

  it { should respond_to(:title) }
  it { should respond_to(:content) }
  it { should respond_to(:user_id) }
  it { should respond_to(:user) }
  it { should respond_to(:published_at) }
  it { should respond_to(:draft) }
  it { should respond_to(:comments_count) }

  its(:draft) { should == false }

  it { should be_valid }
end

我特别想测试

评论数

：我想在帖子中创建评论。他们之间已经有了联系（post

有很多评论）。并检查注释计数是否增加

有谁能给我举个测试的例子吗

当前代码：

comment.rb:

  create_table "posts", :force => true do |t|
    t.string   "title"
    t.string   "content"
    t.integer  "user_id"
    t.datetime "created_at",                               :null => false
    t.datetime "updated_at",                               :null => false
    t.integer  "comments_count",        :default => 0,     :null => false
    t.datetime "published_at"
    t.boolean  "draft",                 :default => false
  end

  create_table "comments", :force => true do |t|
    t.text     "content"
    t.integer  "post_id"
    t.integer  "user_id"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

class Comment < ActiveRecord::Base
  attr_accessible :content, :user_id

  belongs_to :post, :counter_cache => true
  belongs_to :user
end

FactoryGirl.define do
  factory :user do
    username     "Michael Hartl"
    email    "michael@example.com"
    password "foobar"
    password_confirmation "foobar"
  end
end

FactoryGirl.define do
  factory :post do
    title     "Sample Title"
    content    "Sample Content"
    published_at Time.now()
    comments_count 0
    draft false
    association :user
  end
end

require 'spec_helper'

describe Post do
  let(:post) { FactoryGirl.create(:post) }

  subject { post }

  it { should respond_to(:title) }
  it { should respond_to(:content) }
  it { should respond_to(:user_id) }
  it { should respond_to(:user) }
  it { should respond_to(:published_at) }
  it { should respond_to(:draft) }
  it { should respond_to(:comments_count) }

  its(:draft) { should == false }

  it { should be_valid }
end

规格/型号/后规格rb:

  create_table "posts", :force => true do |t|
    t.string   "title"
    t.string   "content"
    t.integer  "user_id"
    t.datetime "created_at",                               :null => false
    t.datetime "updated_at",                               :null => false
    t.integer  "comments_count",        :default => 0,     :null => false
    t.datetime "published_at"
    t.boolean  "draft",                 :default => false
  end

  create_table "comments", :force => true do |t|
    t.text     "content"
    t.integer  "post_id"
    t.integer  "user_id"
    t.datetime "created_at", :null => false
    t.datetime "updated_at", :null => false
  end

class Comment < ActiveRecord::Base
  attr_accessible :content, :user_id

  belongs_to :post, :counter_cache => true
  belongs_to :user
end

FactoryGirl.define do
  factory :user do
    username     "Michael Hartl"
    email    "michael@example.com"
    password "foobar"
    password_confirmation "foobar"
  end
end

FactoryGirl.define do
  factory :post do
    title     "Sample Title"
    content    "Sample Content"
    published_at Time.now()
    comments_count 0
    draft false
    association :user
  end
end

require 'spec_helper'

describe Post do
  let(:post) { FactoryGirl.create(:post) }

  subject { post }

  it { should respond_to(:title) }
  it { should respond_to(:content) }
  it { should respond_to(:user_id) }
  it { should respond_to(:user) }
  it { should respond_to(:published_at) }
  it { should respond_to(:draft) }
  it { should respond_to(:comments_count) }

  its(:draft) { should == false }

  it { should be_valid }
end

（顺便说一句，这是我第一次在我的应用程序中测试一些东西。我测试的是不需要测试的东西吗？是否缺少应该测试的东西？
我们可能需要一个工厂来提供意见：

FactoryGirl.define do
  factory :comment do
    content "Sample comemnt"
    association :user
    association :post
  end
end

下面的测试（我在请求测试中加入了该测试）将进行检查，以确保在用户向表单添加内容并单击右按钮时，确实添加了注释：

describe "New comments" do
  let(:post) FactoryGirl.create(:post)
  let(:user) FactoryGirl.create(:user)

  context "valid with content comment added to database" do

    before do
      visit post_path(post)
      fill_in 'Content', with: "A new comment."
    end

    expect { click_button 'Create Comment' }.to change(Comment, :count).by(1)
  end
end

此测试可能适用于注释模型规范：

describe Comment do
  let(:comment) { FactoryGirl.create(:comment) }

  subject { comment }

  it { should respond_to(:content) }
  it { should respond_to(:user_id) }
  it { should respond_to(:user) }
  it { should respond_to(:post_id) }

  it { should be_valid }

  it "should belong to a post which has a comment count of 1" do
    comment.post.comment_count.should equal 1
  end
end

然后，让这个测试通过的方法是在评论模型中放入一些东西，以便在创建新评论时，更新它所属的帖子中的comment\u count属性

我不能100%确定最后一次测试写得是否正确。我不确定您是否可以覆盖先前定义的主题。
我很好奇：comment\u count。您是否有不使用内置查询@post.comments.count的原因？@new2ruby
：counter\u cache=>true
提高性能。计数是缓存的，当发生更改时，只有一个查询。此时性能是一个巨大的考虑因素吗？一直在帮助我学习rails的那个家伙一直在唠叨我，说我不应该花时间优化那些可能永远不会成为问题的东西。即使我觉得他这样做很烦人，我也不得不用同样的方式来烦扰你@凯文哈，好吧，如果我没有这么做，我以后可能会忘记这么做。非常感谢！我会试试这个。