Rails集成测试创建会话时遇NoMethodError问题求助

执行集成测试时，创建用户登录会话失败，报错如下：

Finished tests in 0.273092s, 3.6618 tests/s, 0.0000 assertions/s.

  1) Error:
ListCategoriesTest#test_should_create_category:
NoMethodError: undefined method `[]' for nil:NilClass

    app/controllers/session_controller.rb:8:in `create'
    test/test_helper.rb:16:in `sign_in_as'
    test/integration/list_categories_test.rb:20:in `block in <class:ListCategoriesTest>'

集成测试文件（test/integration/list_categories.rb） #

require 'test_helper'

class ListCategoriesTest < ActionDispatch::IntegrationTest
  def setup
    @category=Category.create(name: "Sports")
    @admin_user = User.create(username: "fardeen", email: "fardeenmhs@hotmail.com", password: "fardeen", admin: true)
  end

  test "should create category" do
    sign_in_as(@admin_user)
    assert_difference('Category.count',1) do
      post :create, category: { name:"Travel" }
    end

    assert_redirected_to category_path(Category.last)
  end
end

测试辅助函数（test/test_helper.rb） #

ENV["RAILS_ENV"] ||= "test"
require File.expand_path('../../config/environment', __FILE__)
require 'rails/test_help'

class ActiveSupport::TestCase
  ActiveRecord::Migration.check_pending!

  fixtures :all

  def sign_in_as(user)
    post login_path, params:{ session:{"email"=> user.email, "password"=> "fardeen"} }
  end
end

Session控制器（app/controllers/session_controller.rb） #

class SessionController < ApplicationController

  def new
    render 'new'
  end

  def create
    user=User.find_by(email: params[:session][:email].downcase)
    if user and user.authenticate(params[:session][:password])
        flash[:info]="You have been successfully logged in!!!"
        session[:user_id]=user.id
        redirect_to user
    else
        flash[:notice]="Invalid Creds!!!"
        render 'new'
    end
  end

  def destroy
    session[:user_id]=nil
    flash[:info]="You have been logged out!!!"
    redirect_to users_path
  end

end

已尝试的解决方法及结果 #

我尝试过多种传参形式，但都未能解决问题：

1. 调整sign_in_as方法的传参格式：

post login_path, "session"=>{"email"=> user.email, "password"=> "fardeen"} 

无效果，仍报错。

2. 尝试分开传递params和session：

post login_path, params:{}, session:{"email"=> user.email, "password"=> "fardeen"} 

出现新错误：

1) Error:
ListCategoriesTest#test_should_create_category:
ArgumentError: bad argument (expected URI object or URI string)
    test/integration/list_categories_test.rb:22:in `block (2 levels) in <class:ListCategoriesTest>'
    test/integration/list_categories_test.rb:21:in `block in <class:ListCategoriesTest>'

对应的日志：

ListCategoriesTest: test_should_create_category
-----------------------------------------------
  (1.0ms)  SAVEPOINT active_record_1
  Category Exists (0.0ms)  SELECT 1 AS one FROM "categories" WHERE "categories"."name" = 'Sports' LIMIT 1
  SQL (28.1ms)  INSERT INTO "categories" ("created_at", "name", "updated_at") VALUES (?, ?, ?)  [["created_at", Sat, 19 Aug 2023 15:30:44 UTC +00:00], ["name", "Sports"], ["updated_at", Sat, 19 Aug 2023 15:30:44 UTC +00:00]]
  (0.0ms)  RELEASE SAVEPOINT active_record_1
  (0.0ms)  SAVEPOINT active_record_1
  (0.0ms)  ROLLBACK TO SAVEPOINT active_record_1
Started POST "/login" for 127.0.0.1 at 2023-08-19 21:00:44 +0530
Processing by SessionController#create as HTML
  Parameters: {"params"=>{"session"=>{"email"=>"fardeenmhs@hotmail.com", "password"=>"[FILTERED]"}}}
Completed 500 Internal Server Error in 41ms
  (3.0ms)  rollback transaction

3. 尝试简化传参：

def sign_in_as(user)
  post login_path, { session: { email: user.email, password: "fardeen" } }
end

日志显示参数已传递，但登录验证失败，页面重新渲染登录页：

Started POST "/login" for 127.0.0.1 at 2023-08-21 22:14:59 +0530
Processing by SessionController#create as HTML
  Parameters: {"session"=>{"email"=>"fardeenmhs@hotmail.com", "password"=>"[FILTERED]"}}
  User Load (0.0ms)  SELECT "users".* FROM "users" WHERE "users"."email" = 'fardeenmhs@hotmail.com' LIMIT 1
  Rendered users/_footer.html.erb (0.0ms)
  Rendered session/new.html.erb within layouts/application (2.0ms)
  Rendered layouts/_messages.html.erb (0.0ms)
Completed 200 OK in 8ms (Views: 6.0ms | ActiveRecord: 0.0ms)
  (0.0ms)  SELECT COUNT(*) FROM "categories"
  (3.0ms)  rollback transaction

核心疑问 #

我无法理解为什么会出现参数为nil的情况，或者说session哈希无法通过POST请求正确传递？

内容的提问来源于stack exchange，提问作者Fardeen