Rails - Sep 2005 - Automatic functional testing for ajax?

I''ve found that I sometimes forget to provide an action for handling an
ajax request. Of course the problem immediately becomes apparent, when 
I do something to the user interface that triggers the ajax request. 
The problem is that I have to do it manually. I''d feel better if I had 
an automatic way to check that required controllers/actions do exist.

My current idea is as follows:
(1) Forget about the general case, consider only ajax requests related 
to specific helper methods.
(2) Redefine these helper methods in a sandbox environment to write test 
methods.
(3) Render all views and collect the test methods.

I''m not sure whether this approach is workable. Redefining the helper 
methods to do something different, is probably no big deal. The 
scaffold generator uses this technique to write ERb/Rails source code 
instead of HTML.

The catch is (3). What I don''t yet see is how to more or less neuter 
everything apart from the methods I''m interested in. In a tool, I
can''t
provide the same environment for the views that they get when rendered 
from a controller. Rampant use of method_missing and const_missing come 
to mind, still I doubt this is enough.

Ideas? Suggestions? I appreciate your comments.

Michael

-- 
Michael Schuerig                           The more it stays the same,
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org                       
The less it changes!
http://www.schuerig.de/michael/      --Spinal Tap, The Majesty of Rock

On Friday 16 September 2005 02:56, Michael Schuerig wrote:
> (3) Render all views and collect the [ajax] methods.
> The catch is (3). What I don''t yet see is how to more or less
neuter
> everything apart from the methods I''m interested in. In a tool, I
> can''t provide the same environment for the views that they get
when
> rendered from a controller. Rampant use of method_missing and
> const_missing come to mind, still I doubt this is enough.
The first steps proved easier than expected. My main aim is to check the 
ajaxian helper methods I''m using in BoilerPlate. The code below does 
this for two methods. Right now it doesn''t do anymore than simply 
listing the ajax actions required to support the views. I don''t think 
tests can be generated from this automatically, but from the list it is 
pretty easy to write tests for the respective actions anyway. Also, the 
code is imperfect, it gets thrown off its tracks easily. As all the 
stubbed method calls return nil, e.g., operators expecting some other 
type will raise an exception.

Michael


require ''erb''
require ''active_support''


class NilClass
  def method_missing(method, *args)
  end
end

class Sandbox
  def initialize(checker)
    @checker = checker
  end

  def _sandbox_binding
    binding
  end

  def method_missing(method, *args)
  end

  def self.const_missing(const)
  end

  def association_target_chooser_widget(object_name, association_name, 
options = {}, chooser_options = {})
    controller = chooser_options[:controller]  || association_name.to_s
    action     = chooser_options[:ajax_action] || 
"#{association_name}_candidates"
    @checker.collect_ajax_action(controller, action)
  end

  def tree_navigator_widget(object_name, association_name, options = {}, 
navigator_options = {})
    controller = navigator_options[:controller]  || 
association_name.to_s
    action     = navigator_options[:ajax_action] || 
"child_#{Inflector.pluralize(association_name)}"
    @checker.collect_ajax_action(controller, action)
  end
end


class Checker
  def initialize
    @ajax_actions = Hash.new([])
  end

  def collect_ajax_actions
    ARGV.each do |view_file|
      begin
        @current_view = view_file
        ERB.new(File.read(view_file), nil,
''-'').result(sandbox_binding)
#      rescue
#        $stderr.puts "Error while looking for calls in #{view_file}: 
#{$!}"
      end
    end
  end

  def collect_ajax_action(controller, action)
    ca = [ controller.to_s, action.to_s ]
    @ajax_actions[ca] = @ajax_actions[ca] + [ @current_view ]
  end

  def check_ajax_actions
    @ajax_actions.each do |ca, views|
      controller, action = ca
      puts "CHECKING #{controller}/#{action}: #{views.inspect}"

    end
  end

  def check
    collect_ajax_actions
    check_ajax_actions
  end

  def self.check
    Checker.new.check
  end

  def sandbox_binding
    Sandbox.new(self)._sandbox_binding
  end
end

Checker.check


-- 
Michael Schuerig                             Those who call the shots
mailto:michael-q5aiKMLteq4b1SvskN2V4Q@public.gmane.org              Are never in
the line of fire
http://www.schuerig.de/michael/           --Ani DiFranco, Not So Soft