Error when providing a class argument to ActiveJob for classes that implement permitted?

[adnanrh]

Steps to reproduce

1. Write a class MyClass that implements a class method named permitted?
2. Write a job BuggyJob with a perform method that accepts a class as a parameter
3. Enqueue a BuggyJob job with MyClass as an argument: BuggyJob.perform_later(MyClass)

The issue seems to be here: https://github.com/rails/rails/blob/main/activejob/lib/active_job/arguments.rb#L93
It seems in the switch statement to choose the correct serializer for the argument, we attempt to call serialize_indifferent_hash on argument.to_h if it responds to permitted?. I suppose the assumption here is that if the argument responds to permitted?, it should be an instance of ActionController::Parameters? In our app, we have a module that defines a class method named permitted? for some other business logic and it's used in a few classes.

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "activejob", "~> 7.0.0"
end

require "minitest/autorun"
require "active_job"

class MyClass
  def self.permitted?
    # noop
  end
end

class BuggyJob < ActiveJob::Base
  def perform(klass)
    puts "performed"
  end
end

class BuggyJobTest < ActiveJob::TestCase
  def test_stuff
    error = assert_raises(NoMethodError) { BuggyJob.perform_later(MyClass) }
    assert_match /undefined method `to_h' for MyClass:Class/, error.message
  end
end

Expected behavior

A BuggyJob job should successfully be queued, with the MyClass argument serialized using ActiveJob::Serializers::ModuleSerializer.

Actual behavior

A NoMethodError is raised:

Failed enqueuing BuggyJob to DelayedJob(default): NoMethodError (undefined method `to_h' for MyClass:Class
Did you mean?  to_s)
.../ruby/3.0.0/gems/activejob-6.1.7.3/lib/active_job/arguments.rb:120:in `serialize_argument': undefined method `to_h' for MyClass:Class (NoMethodError)
Did you mean?  to_s

System configuration

Rails version: Tested on 6.1.x, 7.0.x

Ruby version: Tested on 3.0.4

[abaldwin88]

Removing these two lines allows BuggyJob.perform_later(MyClass) to be called in the test case without an error being raised

rails/activejob/lib/active_job/arguments.rb

Lines 93 to 94 in 06da26a

	when -> (arg) { arg.respond_to?(:permitted?) }
	serialize_indifferent_hash(argument.to_h)

[sampatbadhe]

How about checking argument is responding to to_h along with permitted?

rails/activejob/lib/active_job/arguments.rb

Line 93 in 06da26a

when -> (arg) { arg.respond_to?(:permitted?) }

-        when -> (arg) { arg.respond_to?(:permitted?) }
+        when -> (arg) { arg.respond_to?(:permitted?) && arg.respond_to?(:to_h) }

[abaldwin88]

It'd be nice to explicitly check whether the class is ActionController::Parameters ?

The drawback with that approach though is ActiveJob would become tightly coupled to ActionController. We'd need to require "action_controller/metal/strong_parameters".

Adding to_h seems like the best course. I'll open a PR and add you as a co-author @sampatbadhe