RSpec 会话控制器规范中 nil:NilClass 的未定义方法“[]”

Question

我有一个简单的消息应用程序可以学习 RSpec 其中一个用户可以创建消息给另一个用户（只有登录的用户才能写消息）。我没有使用设计来登录或注册用户，这个应用程序尽可能简单只是为了rspec学习。

我想测试会话控制器中的创建方法：

class SessionsController < ApplicationController
  before_action :logged_in_redirect, only: %i[new create]

  def new; end

  def create
    user = User.find_by(username: params[:session][:username])
    if user && user.authenticate(params[:session][:password])
      session[:user_id] = user.id
      flash[:success] = 'You have successfully logged in'
      redirect_to root_path
    else
      flash.now[:error] = 'There was something wrong with your login'
      render 'new'
    end
  end

  def logged_in_redirect
    if logged_in?
      flash[:error] = 'You are already logged in'
      redirect_to root_path
    end
  end

这是我的会话控制器规范中的相关代码：

RSpec.describe SessionsController, type: :controller do
  describe 'POST #create' do
    context 'when password is correct' do
      let(:user) { User.create(username: 'John', password: 'test123') }
      it 'redirect to root path' do
        post :create, session: { username: 'John', password: 'test123' }

        expect(response).to have_http_status(:redirect)
      end
    end
  end
end

错误显示 nil:NilClass 的未定义方法“[]”。它在应用程序中按预期工作。我错过了什么？我应该在 let(:user) 之后使用 session[:user_id] 吗？

Answer 1

Use let to define a memoized helper method. The value will be cached across multiple calls in the same example but not across examples. Note that let is lazy-evaluated: it is not evaluated until the first time the method it defines is invoked. You can use let! to force the - List item

method's invocation before each example. xou can refer this to get further detailsrelish docs

可能性 1

RSpec.describe SessionsController, type: :controller do

      describe 'POST #create' do

        before :each do
         @user = User.create(username: 'John', password: 'test123') 
        end

        context 'when password is correct' do

          it 'redirect to root path' do
            post :create, params: {session: { username: @user.username, password: @user.password }}

            expect(response).to have_http_status(:redirect)
          end
        end
      end
    end

可能性2

RSpec.describe SessionsController, type: :controller do

        let(:create_user) do 
          @user = User.create(username: 'John', password: 'test123') 
        end

      describe 'POST #create' do
        context 'when password is correct' do

          it 'redirect to root path' do
            create_user

            post :create, params: {session: { username: @user.username, password: @user.password }}

            expect(response).to have_http_status(:redirect)
          end
        end
      end
    end

RSpec 会话控制器规范中 nil:NilClass 的未定义方法“[]”

RSpec undefined method `[]' for nil:NilClass in sessions controller spec

rspec

ruby-on-rails

rspec-rails