RSpec：未定义的方法`assert_difference'for ...（NoMethodError）

3 回答

• 5

  确保在spec / spec_helper.rb中包含AssertDifference：

  RSpec.configure do |config|
    ...   
    config.include AssertDifference
  end
  

  并将断言放在 it 块中：

  it 'event count should change' do
    assert_difference 'Event.count' do
      ...
    end
  end
  

  回复于 2024-05-03T09:01:45+08:00
• 4

  如果您正在使用RSPEC，那么绝对应该“改变” . 这里有两个例子，一个是负面的，一个是正面的，所以你可以理解一下语法：

  RSpec.describe "UsersSignups", type: :request do
    describe "signing up with invalid information" do
      it "should not work and should go back to the signup form" do
        get signup_path
        expect do
          post users_path, user: { 
            first_name:            "",
            last_name:             "miki",
            email:                 "user@triculi",
            password:              "buajaja",
            password_confirmation: "juababa" 
          }
        end.to_not change{ User.count }
        expect(response).to render_template(:new)
        expect(response.body).to include('errors')
      end
    end
  
    describe "signing up with valid information" do
      it "should work and should redirect to user's show view" do
        get signup_path
        expect do
          post_via_redirect users_path, user: { 
            first_name:            "Julito",
            last_name:             "Triculi",
            email:                 "triculito@mail.com",
            password:              "worldtriculi",
            password_confirmation: "worldtriculi"
          }
        end.to change{ User.count }.from(0).to(1)
        expect(response).to render_template(:show)
        expect(flash[:success]).to_not be(nil)
      end
    end
  

  回复于 2024-05-03T09:01:45+08:00
• 4

  我最好用change重写一下 .

  这在RSpec 3.x中确实有效，但也可能在旧版本中使用 .

  context 'with event_type is available create event' do
    let(:event_type) { EventType.where( name: 'visit_site').first }
  
    it "changes event counter" do
      expect { Event.fire_event(event_type, @sponge,{}) }.to change { Event.count }
    end
  end # with event_type is available create event
  

  回复于 2024-05-03T09:01:45+08:00