使用cucumber测试时sql错误无法在事务内启动事务

我是黄瓜新手，正在学习 BDD

当我尝试填写表单并创建记录时，会显示此 sqlite 错误，尽管当我在浏览器中手动尝试代码时没有错误。

我正在使用 Rails 4。

这是我的控制器代码

class Admin::ItemsController < ApplicationController
    def index
        @items=Item.all
    end

    def new
        @item=Item.new
    end

    def create
        @item=Item.new items_params
            respond_to do |format|
                if @item.save
                    format.html { redirect_to admin_items_path }
                else
                    format.html { redirect_to new_admin_items_path }
                end
            end
    end

private
    def items_params
        params.require(:item).permit(:name,:price)      
    end
end

这是我的功能文件

Feature: Manage Items
  In order to make a store
  As an admin
  I want to create and manage items

  Scenario: Items List
    Given I go to the new admin item page
    And I fill in "Name" with "Shampoo"
    And I fill in "Price" with "50"
    When I press "Create"
    Then I should be on the admin items page
    And I should see "Shampoo"

和步骤定义

require File.expand_path(File.join(File.dirname(__FILE__), "..", "support", "paths"))

Given /^I go to the (.+)$/ do |page_name|
  visit path_to(page_name)
end

And /^I fill in "([^\"]*)" with "([^\"]*)"$/ do |field, value|
  fill_in(field.gsub(' ', '_'), :with => value)
end

When /^I press "([^\"]*)"$/ do |button|
  click_button(button)
end

Then /^I should be on the (.+)$/ do |page_name|
  current_path.should == path_to(page_name)
end

And /^I should see "(.*?)"$/ do |arg1|
  page.should have_content(arg1)
end

此错误显示在步骤 4 中，即单击“创建”按钮并调用 items#create 时。

我不知道代码有什么问题，希望有人能帮忙。

UPDATE:

我想问题出在 cucumber-rails 中的弃用https://github.com/cucumber/cucumber-rails/issues/231 https://github.com/cucumber/cucumber-rails/issues/231

完整轨迹：

Using the default profile...
WARNING: Nokogiri was built against LibXML version 2.7.8, but has dynamically loaded 2.9.0
DEPRECATION WARNING: ActionController::Integration is deprecated and will be removed, use ActionDispatch::Integration instead. (called from <module:Rails> at /home/phanindra/.gem/ruby/1.9.1/gems/cucumber-rails-1.3.0/lib/cucumber/rails/world.rb:9)
DEPRECATION WARNING: ActionController::IntegrationTest is deprecated and will be removed, use ActionDispatch::IntegrationTest instead. (called from <module:Rails> at /home/phanindra/.gem/ruby/1.9.1/gems/cucumber-rails-1.3.0/lib/cucumber/rails/world.rb:9)
Feature: Manage Items
  In order to make a store
  As an admin
  I want to create and manage items

  Scenario: Items List                       # features/manage_items.feature:6
DEPRECATION WARNING: #increment_open_transactions is deprecated and has no effect. (called from start at /home/phanindra/.gem/ruby/1.9.1/gems/database_cleaner-0.9.1/lib/database_cleaner/active_record/transaction.rb:11)
    Given I go to the new admin item page    # features/step_definitions/item_steps.rb:3
    And I fill in "Name" with "Shampoo"      # features/step_definitions/item_steps.rb:7
    And I fill in "Price" with "50"          # features/step_definitions/item_steps.rb:7
    When I press "Create"                    # features/step_definitions/item_steps.rb:11
      SQLite3::SQLException: cannot start a transaction within a transaction: begin transaction (ActiveRecord::StatementInvalid)
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb:353:in `block in begin_db_transaction'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb:305:in `block in log'
      /home/phanindra/rails/activesupport/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb:300:in `log'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb:353:in `begin_db_transaction'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb:129:in `initialize'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb:17:in `new'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/transaction.rb:17:in `begin'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb:231:in `begin_transaction'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb:208:in `within_new_transaction'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `transaction'
      /home/phanindra/rails/activerecord/lib/active_record/transactions.rb:209:in `transaction'
      /home/phanindra/rails/activerecord/lib/active_record/transactions.rb:319:in `with_transaction_returning_status'
      /home/phanindra/rails/activerecord/lib/active_record/transactions.rb:269:in `block in save'
      /home/phanindra/rails/activerecord/lib/active_record/transactions.rb:280:in `rollback_active_record_state!'
      /home/phanindra/rails/activerecord/lib/active_record/transactions.rb:268:in `save'
      /home/phanindra/rails/activerecord/lib/active_record/persistence.rb:37:in `create'
      ./app/controllers/admin/items_controller.rb:11:in `create'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
      /home/phanindra/rails/actionpack/lib/abstract_controller/base.rb:189:in `process_action'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/rendering.rb:10:in `process_action'
      /home/phanindra/rails/actionpack/lib/abstract_controller/callbacks.rb:18:in `block in process_action'
      /home/phanindra/rails/activesupport/lib/active_support/callbacks.rb:393:in `_run__143383953690284082__process_action__callbacks'
      /home/phanindra/rails/activesupport/lib/active_support/callbacks.rb:78:in `run_callbacks'
      /home/phanindra/rails/actionpack/lib/abstract_controller/callbacks.rb:17:in `process_action'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/rescue.rb:29:in `process_action'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
      /home/phanindra/rails/activesupport/lib/active_support/notifications.rb:158:in `block in instrument'
      /home/phanindra/rails/activesupport/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
      /home/phanindra/rails/activesupport/lib/active_support/notifications.rb:158:in `instrument'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/instrumentation.rb:30:in `process_action'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
      /home/phanindra/rails/activerecord/lib/active_record/railties/controller_runtime.rb:18:in `process_action'
      /home/phanindra/rails/actionpack/lib/abstract_controller/base.rb:136:in `process'
      /home/phanindra/rails/actionpack/lib/abstract_controller/rendering.rb:44:in `process'
      /home/phanindra/rails/actionpack/lib/action_controller/metal.rb:195:in `dispatch'
      /home/phanindra/rails/actionpack/lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
      /home/phanindra/rails/actionpack/lib/action_controller/metal.rb:231:in `block in action'
      /home/phanindra/rails/actionpack/lib/action_dispatch/routing/route_set.rb:77:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/routing/route_set.rb:77:in `dispatch'
      /home/phanindra/rails/actionpack/lib/action_dispatch/routing/route_set.rb:45:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/journey/router.rb:69:in `block in call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/journey/router.rb:57:in `each'
      /home/phanindra/rails/actionpack/lib/action_dispatch/journey/router.rb:57:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/routing/route_set.rb:614:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/params_parser.rb:30:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/flash.rb:233:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/cookies.rb:443:in `call'
      /home/phanindra/rails/activerecord/lib/active_record/query_cache.rb:36:in `call'
      /home/phanindra/rails/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb:632:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
      /home/phanindra/rails/activesupport/lib/active_support/callbacks.rb:373:in `_run__2084705409073281596__call__callbacks'
      /home/phanindra/rails/activesupport/lib/active_support/callbacks.rb:78:in `run_callbacks'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb:18:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
      /home/phanindra/rails/railties/lib/rails/rack/logger.rb:32:in `call_app'
      /home/phanindra/rails/railties/lib/rails/rack/logger.rb:16:in `block in call'
      /home/phanindra/rails/activesupport/lib/active_support/tagged_logging.rb:67:in `block in tagged'
      /home/phanindra/rails/activesupport/lib/active_support/tagged_logging.rb:25:in `tagged'
      /home/phanindra/rails/activesupport/lib/active_support/tagged_logging.rb:67:in `tagged'
      /home/phanindra/rails/railties/lib/rails/rack/logger.rb:16:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/request_id.rb:21:in `call'
      /home/phanindra/rails/activesupport/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
      /home/phanindra/rails/actionpack/lib/action_dispatch/middleware/static.rb:63:in `call'
      /home/phanindra/rails/railties/lib/rails/engine.rb:508:in `call'
      /home/phanindra/rails/railties/lib/rails/application.rb:95:in `call'
      ./features/step_definitions/item_steps.rb:12:in `/^I press "([^\"]*)"$/'
      features/manage_items.feature:10:in `When I press "Create"'
    Then I should be on the admin items page # features/step_definitions/item_steps.rb:15
    And I should see "Shampoo"               # features/step_definitions/item_steps.rb:19

Failing Scenarios:
cucumber features/manage_items.feature:6 # Scenario: Items List

1 scenario (1 failed)
6 steps (1 failed, 2 skipped, 3 passed)
0m3.476s

看起来您正在使用 DatabaseCleaner，它默认在事务中运行您的每个功能。同时，ActiveRecord 本身在保存项目时启动一个事务。不幸的是，SQLite 不支持嵌套事务。

If you 改变你的DatabaseCleaner策略 https://github.com/bmabey/database_cleaner#how-to-use to :truncation它应该避免这个错误。或者，您可以针对功能更强大的数据库（例如 PostgreSQL）进行测试。