Rspec（用于 Michael Hartl 示例）用于定义跟随用户的关系

Question

我正在尝试对MHartl's example 进行规格测试。 如下所示，我的困难在于#Follows 用户。

class User < ActiveRecord::Base

  # Associations
  has_many :active_relationships, class_name:  "Relationship",
                                  foreign_key: "follower_id",
                                  dependent:   :destroy
  has_many :following, through: :active_relationships, source: :followed
  has_many :followers, through: :passive_relationships, source: :follower

  # Follows a user.
  def follow(other_user)
    active_relationships.create(followed_id: other_user.id)
  end

  # Unfollows a user.
  def unfollow(other_user)
    active_relationships.find_by(followed_id: other_user.id).destroy
  end

  # Returns true if the current user is following the other user.
  def following?(other_user)
    following.include?(other_user)
  end

对于我的规范：

require 'rails_helper'

RSpec.describe User, :type => :model do
  let(:user) { build(:user) }

  describe 'Validations' do
    it 'has a valid factory' do
      expect(user).to be_valid
    end

    it { should validate_presence_of(:email) }
    it { should validate_presence_of(:password) }
    it { should validate_confirmation_of(:password) }
  end


  let(:user) { create(:user) }
  let(:other_user) { create(:user) }

  describe '#following?' do
    it "expect relationship between two users to be empty" do
      expect(user.active_relationships).to be_empty
    end
  end

  describe '#follow' do
    it "creates the active relationship between two users" do
      user.follow(other_user)
      expect(user.active_relationships.first.followed_id).to eq(other_user.id)
    end

    it "creates the passive relationship between two users" do
      user.follow(other_user)
      expect(other_user.passive_relationships.first.follower_id).to eq(user.id)
    end
  end

  describe '#unfollow' do
    it "destroys the active relationship between two users" do
      user.follow(other_user)
      user.unfollow(other_user)
      expect(user.active_relationships.find_by.followed_id).to change(Relationship, :count).by(-1)
    end
  end

我的失败：

1) User#unfollow destroys the active relationship between two users
     Failure/Error: active_relationships.find_by(followed_id: other_user.id).destroy

     NoMethodError:
       undefined method `destroy' for nil:NilClass

  2) User#follow creates the passive relationship between two users
     Failure/Error: expect(other_user.passive_relationships.first.follower_id).to eq(user.id)

     NoMethodError:
       undefined method `passive_relationships' for #<User:0x0000010c4146e8>

如果您需要有关此帖子的更多信息，请随时询问！ 请告诉我，我可以了解更多有关此规格测试的信息吗？ 谢谢你的帮助:)

Answer 1

您在 User 模型中缺少 :passive_relationships 关系，该模型反映了 :active_relationships 关系：

has_many :passive_relationships, class_name:  "Relationship",
                                 foreign_key: "followed_id",
                                 dependent:   :destroy

Answer 2

最好在let 中创建此其他用户，并将build 替换为create，因为您没有验证新的未保存记录：

let(:user) { create(:user) }
let(:other_user) { create(:user) }

然后

user.follow(other_user)