ruby-on-rails - 在 Rails 2.3+ 中测试(rspec)嵌套模型部分

Question

借助嵌套模型的 2.3.x+ Rails 功能，我认为我需要访问表单构建器实例以正确指定部分以渲染嵌套模型。从复杂形式示例中提取:

例如，下面是一个封闭表单，它创建表单构建器并将其传递给嵌套模型渲染 View :

<div class="children_fields tasks" id="<%= dom_id(f.object) %>_tasks"  
   data-context="<%= f.object_name %>">
  <% f.fields_for :tasks do |task_form| %>
    <%= render :partial => 'task', :locals => { :f => task_form } %>
  <% end %>    
</div>

任务部分是:

<%= f.label :name, "Task" %>
<%= f.text_field :name %>
<%= remove_child_link "remove", '#', f %>
<div class="children_fields assignments" id="<%= dom_id(f.object) %>_assignments"  
     data-context="<%= f.object_name %>">
  <% f.fields_for :assignments do |assignment_form| %>
    <%= render :partial => 'assignment', :locals => { :f => assignment_form } %>
  <% end %>
</div>

当我尝试指定这样的部分时，我尝试通过执行以下操作将表单生成器捕获为实例变量:

before(:each) do
  ... # setup for target object
  form_for [:foo, :bar, @project] do |f|
    @f = f
  end
end

这会在使用 form_for 时引发错误

undefined method `polymorphic_path' for #<Spec::Rails::Example::ViewExampleGroup::Subclass_1:0x2cfeafc>
/Users/adamaig/.rvm/gems/ruby/1.8.7/gems/actionpack-2.3.5/lib/action_controller/test_process.rb:511:in `method_missing'
/Users/adamaig/.rvm/gems/ruby/1.8.7/gems/actionpack-2.3.5/lib/action_view/helpers/form_helper.rb:298:in `apply_form_for_options!'
/Users/adamaig/.rvm/gems/ruby/1.8.7/gems/actionpack-2.3.5/lib/action_view/helpers/form_helper.rb:272:in `form_for'

那么，正确的方法是什么: 1)获取这样规范的 FormBuilder 实例？ 2) 规范嵌套模型及其 View 形式？

这对于正确名称的生成很重要。

Answer 1

解决方案是:

describe 'tasks/_form' do
  attr_accessor :output_buffer

  before do
    task = mock_model(Task, :mumbo_jumbo => 'foo bar')
    @output_buffer = ''
    form_for(task, :url => task_path(task)) do |f|
      @f = f
    end
  end

  it 'should have input mumbo_jumbo' do
    render_partial_with_locals
    response.should have_tag('input[name=?]', 'task[mumbo_jumbo]')
  end

  private

    def render_partial_with_locals
      render :partial => 'tasks/form', :locals => {:f => @f}
    end

    def protect_against_forgery?
      false
    end
end