Rails系统测试中Turbo Action Cable关联Job未执行的原因及解决

问题 #

基于Rails、Turbo和Action Cable开发的项目，开发环境运行正常，但系统测试环节Action Cable无响应。排查发现系统测试中Action Job既未入队也未执行，在create动作调试时甚至无法找到变量。测试断言expect(PlayJob).to have_been_enqueued失败，报错信息：

Failure/Error: expect(PlayJob).to have_been_enqueued
       expected to enqueue exactly 1 jobs, but enqueued 0

相关代码 #

系统测试代码（spec/system/grids_spec.rb）

RSpec.describe 'Grids', type: :system do
  it 'creates grid' do
    visit root_path

    click_on 'Create Grid'

    expect do
      sleep 0.2
    end.to change { find('#grid').html }
  end
end

控制器代码（app/controllers/grids_controller.rb）

class GridsController < ApplicationController
  def create
    @grid_data = GridData.new(**grid_params)

    if @grid_data.valid?
      play
    else
      render :new, status: :unprocessable_entity
    end
  end

  private
  
  def play
    render :play, status: :created
    PlayJob.perform_later(**@grid_data.attributes)
  end
end

Job代码（app/jobs/play_job.rb）

class PlayJob < ApplicationJob
  queue_as :default

  def perform(**grid_attributes)
    GridData.new(grid_attributes).to_grid.play
  end
end

Grid类代码（lib/grid.rb）

class Grid
  def play
    print
    2.upto(@phases) do
      sleep(@phase_duration)
      next_phase
      print
    end
  end

  def print
    Turbo::StreamsChannel.broadcast_update_to(
      'play',
      target: 'grid',
      partial: 'grids/grid',
      locals: { grid: self }
    )
  end
end

解决方案 #

1. 配置系统测试的Job环境 #

Rails系统测试默认未启用Job队列断言支持，且不会自动执行Job。需在spec/spec_helper.rb或spec/system_helper.rb中添加配置：

RSpec.configure do |config|
  config.before(:each, type: :system) do
    # 启用Job队列测试匹配器
    require 'rspec/rails/matchers/active_job'
    # 配置Job入队模式：:test用于断言，:inline则立即执行Job
    ActiveJob::Base.queue_adapter = :test
  end
end

若需要Job在测试中立即执行以触发Action Cable更新，可将适配器改为:inline。

2. 确保表单参数正确提交 #

测试中点击"Create Grid"时，若未填充必要表单字段，会导致@grid_data验证失败，跳过play方法执行。需补充表单填充步骤：

it 'creates grid' do
  visit root_path

  # 根据实际表单字段填充参数，示例为rows/columns
  fill_in 'Rows', with: 5
  fill_in 'Columns', with: 5
  click_on 'Create Grid'

  expect(PlayJob).to have_been_enqueued
  expect do
    sleep 0.5
  end.to change { find('#grid').html }
end

3. 验证@grid_data的有效性 #

若@grid_data.valid?返回false，play方法不会被调用。可在控制器中添加日志排查验证问题：

def create
  @grid_data = GridData.new(**grid_params)
  Rails.logger.debug "GridData验证错误：#{@grid_data.errors.full_messages}"
  if @grid_data.valid?
    play
  else
    render :new, status: :unprocessable_entity
  end
end

4. 启用系统测试的Action Cable支持 #

需确保测试环境配置了Cable连接，在spec/system_helper.rb中添加：

RSpec.configure do |config|
  config.before(:each, type: :system) do
    driven_by :selenium, using: :chrome, screen_size: [1400, 1400]
    # 用Puma启动服务器以支持Action Cable
    Capybara.server = :puma, { Silent: true }
  end
end

同时检查config/cable.yml的测试环境配置：

test:
  adapter: async

内容的提问来源于stack exchange，提问作者Chiara Ani