Rspec（用於Michael Hartl示例）用於定義用戶之間的關係

Question

我試圖對MHartl's example進行規範測試。 如下圖所示，我的困難在於＃關注用戶。

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 

對於我的規格：

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 

我的錯誤：

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> 

如果您需要了解這個職位的詳細信息，請下跌免費問！ 請告訴我，我可以瞭解更多關於這個規格測試。 感謝您的幫助:)

Answer 1

您錯過User模型中的:passive_relationships關係，該模型反映:active_relationships關係：

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

Answer 2

可以更好地創造let這個其他用戶，並與create取代build，因爲你沒有確認一個新的未保存記錄：

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

然後

user.follow(other_user)