Load Parameters configurations on :action_controller only once

[albertoalmagro]

Summary

This PR fixes the regression where ActionController::UnpermittedParameters exceptions are not being raised.

To accomplish that the following has been made:

• Allow ActiveSupport::LazyLoadHooks to be executed only once.
  Provide run_once: true option to on_load in case you want a hook only to be executed once. This may be useful in cases where executing a hook several times may have undesired side effects. Example: ActiveSupport.on_load(:action_controller, run_once: true)
• Load Parameters configurations on :action_controller only once.
  By using the new ActiveSupport::LazyLoadHooksfunctionality described above fixes regression ActionController::UnpermittedParameters not raised. The inner hook was being executed twice, once when ActionController::Base was loaded and again when ActionController::API was loaded. As options.delete operations inside the block are not idempotent, the second time it was run there was no configuration option available.

Other Information

More information can be found in Issue 30025.

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[betesh]

Does ActionController::API not use strong parameters?

[rafaelfranca]

So the problem is because we run this block twice and after the first one we delete the values, so the second one we get the default values (which is false).

Yeah, we still need to make sure it will run for ActionController::API.

I think we need an new concept that are lazy load hooks that are only executed once. Something like:

ActiveSupport.on_load(:action_controller_base, only_once: true) do

Could you implement that?

[albertoalmagro]

Yes you are right, it doesn't cover ActionController::API.

@rafaelfranca where do you see that it is executed twice? Is the same hook registered twice?

[rafaelfranca]

No, it is executed twice. One for ActionController::Base and other for ActionController::API. This is why changing to on_load(:action_controller_base) fix the problem, because it only run for ActionController::Base

[albertoalmagro]

Now I see @rafaelfranca, the first time the hook is executed this line deletes the value for :action_on_unpermitted_parameters and the next time it gets executed options[:action_on_unpermitted_parameters] is nil and the value gets overwritten.

I will correct the PR accordingly.

[kirs]

What if we stop deleting / mutating the values in the callback? Then we wouldn't need to introduce the complexity of only_once.

[albertoalmagro]

@rafaelfranca @betesh changes done and PR description updated.

[rafaelfranca]

This is great! I made a commend about the implementation that I think can be simpler.

[rafaelfranca]

I wonder if we can delete the hook from @load_hooks just after it is executed if :only_once is true instead of adding a new hash.

[albertoalmagro]

Hey! Sure I will try tomorrow, now it is 1:10 am here. Thanks!!!

[albertoalmagro]

Hi @rafaelfranca , I have been trying this and it gets tricky. The main issue is that on_load and run_load_hooks can be called in any given order and both execute hooks. If you run_load_hooks for two objects like I do in this test, when on_load gets executed, you don't check @load_hooks so you will need some extra structure to know if the hook was ever executed. Having tried this I find the @only_once hash more intention revealing and I like how it separates the :only_once logic without interfering with the already existing functionality. What do you think?

[rafaelfranca]

That makes sense to me.

[rafaelfranca]

This method can be private

[rafaelfranca]

This method can be private

[rafaelfranca]

This method can be private

[rafaelfranca]

This method can be private

[albertoalmagro]

@rafaelfranca done, I made methods private and rebased. Thanks!

[kaspth]

This seems a little too abstracted for my taste. I think it would be clearer if we kept the once checking responsibility within the same method:

def execute_hook(name, base, options, block)
  with_once_execution(name, block, options[:only_once]) do
    if options[:yield]
      block.call(base)
    else
      base.instance_eval(&block)
    end
  end
end

def with_once_execution(name, block, once)
  unless @only_once[name].include?(block)
    @only_once[name] << block if once

    yield
  end
end

(I'd probably just call the option once: true since the only_ is already implied.)

[albertoalmagro]

@kaspth I really like your proposal, I have applied it but changing the method's name to with_execution_control instead of with_once_execution. with_execution_control suggests me that we are doing some control to determine if the hook will be executed or not whereas with_once_execution feels to me like it will always be one single execution.

I have also renamed the option to :run_once because I think it expresses better its intention.

@rafaelfranca please also review last changes.

[rafaelfranca]

Just to confirm, does the application that you are reproducing this bug has ActionController::Api classes?

[albertoalmagro]

Yes @rafaelfranca , I can confirm it. I have debugged it and I see how the hook is registered for both ActionController::Base and ActionController::API. I have also created a Rails app using this branch and reproduced the bug without using :run_once. After adding :run_once the problem is solved 😄

[kaspth]

Where is name coming from here? Previously execute_hook was changed to pass it in.

[albertoalmagro]

Good catch @kaspth I wonder why tests didn't blow up. Since this is merged, please tell me how should I fix it?

[albertoalmagro]

@kaspth I already have a branch to pass the name. Should I open a new PR and reference this one?

[rafaelfranca]

Yes please

[albertoalmagro]

@rafaelfranca @kaspth Done please check PR #30285