I don't understand what you mean. In my unit tests involving ParseFormatUtils for instance Rails is never loaded and my application doesn't even use ActiveRecord.

But my tests weren't complaining anyway because they don't autoload ActionView/Helpers.

Also, even if I explicitly required as/rails it wouldn't fix the situation for my case.

This is what's happening in a simplified way:


./test.rb:
autoload :A, 'a'
require 'a/b'

./lib/a.rb:
module A
  autoload :B, 'a/b'
  include B
end

./lib/a/b.rb:
module A
  module B
  end
end

ruby -I lib test.rb


This is enough to create the circular dependency error. Maybe this is one of the reasons why Matz wants to remove autoload from Ruby...

Sorry but I don't have any suggestions right now that would make require 'a/b' work if 'a' is set to be autoloaded and 'a' requires 'b' which depends on 'a'...

Unless we create some 'action_view/helpers/all.rb' file. Would that be acceptable?

Best,
Rodrigo.

Em 08-02-2013 15:26, Xavier Noria escreveu:
No, no, as/rails.rb is already required by the entry point
of every component (except AS). That is a given in the
context of a Rails application, and

    gem 'active_record'

does that if standalone.

Sent from my iPhone

On 08/02/2013, at 18:12, Rodrigo Rosenfeld Rosas <[email protected] <mailto:[email protected]>> wrote:

Em 08-02-2013 15:00, Xavier Noria escreveu:
Some very common files are loaded at the entry point of every component, to avoid repeating their require again and again:

https://github.com/rails/rails/blob/master/activesupport/lib/active_support/rails.rb

But shouldn't helpers.rb require 'active_support/rails' then instead of just 'active_support/benchmarkable'?

Otherwise it should be documented that we're not supposed to require specific parts of some libraries included in Rails... That way I'd know (although surprised) that I'm not supposed to require 'action_view/helpers/number_helper' but simply 'action_view/helpers' (or just 'action_view'?)


As for the autoload + include, I don't really know, maybe it is a fancy way to avoid writing a file path. Seems unnecessary to me at first glance. Maybe someone else from the team has a better justification?

Sent from my iPhone

On 08/02/2013, at 17:45, Rodrigo Rosenfeld Rosas <[email protected] <mailto:[email protected]>> wrote:

Em 08-02-2013 13:03, Xavier Noria escreveu:
On Fri, Feb 8, 2013 at 3:18 PM, Rodrigo Rosenfeld Rosas
<[email protected]>  wrote:

Em 08-02-2013 12:06, Xavier Noria escreveu:

Seems unrelated to dependencies.rb, most likely a missing require
somewhere within Rails.

It can be the case that it does not show up in production because of eager
loading.
Any ideas why helpers.rb is loaded when you write code like below?

module ActionView
   module Helpers
     module NumberHelper

Is this normal MRI behavior or is this caused by dependencies.rb?
Ruby on Rails itself does not use dependencies.rb to load its code. It
is a regular Ruby library that uses requires and Kernel#autoload with
some added sugar. AS::Dependencies only covers application constant
autoloading.

The thing goes like this: When an application boots in any environment
action_view.rb is loaded. When that file is executed an autoload for
:Helpers is configured under ActionView. In a default setup,
helpers.rb is not yet loaded. That is, if you run

     rails runner 1

helpers.rb is not loaded (at least in 3-2-stable, not that we are
explaining any contract, only load order execution to follow what
happens in your exception).

But if you force the evaluation of the constant as in your example above:

     module ActionView
       module Helpers
         ...
       end
     end

that autoload is triggered because the interpreter checks whether
"Helpers" is a constant defined in the module object stored in
ActionView. Therefore, helpers.rb is interpreted and sets in turn an
autoload for NumberHelper below AV::Helpers.

So, module Helpers in that snippet *reopens* a module object defined
via the autoload, rather than creating the module object. The
execution follows and the same happens with the "NumberHelper"
constant down below. The interpreter checks whether it belongs to the
module object stored in AV::Helpers. Since it is unknown and there is
an autoload for it it gets triggered, and loads... well the very
number_helper.rb whose execution we were in the middle of (not sure
this sentence is valid English :).

I suspect there is a circularity here that is showing up that way.

Would need to dig deeper to fully explain how this ends up in an
exception, maybe I'll do it tonight, but in the meantime here's some
context in case it helps.

It makes total sense. What doesn't make sense is the source of helpers.rb to me:

https://github.com/rails/rails/blob/master/actionpack/lib/action_view/helpers.rb

First it should explicitly require (or require_dependency) 'active_support/autoload' and 'active_support/concern', right?

But then, why using autoload if you're just including all modules next?

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