Make chains comparable by #== based on contents

This is useful behavior on its own, but is also necessary to ensure callbacks from a base app-level Hanami::Action class propogate all the way through a slice-level base class to an individual action class.

hanami-utils.gemspec

@@ -20,6 +20,7 @@ Gem::Specification.new do |spec|
   spec.metadata["rubygems_mfa_required"] = "true"
   spec.required_ruby_version = ">= 3.0"
 
+  spec.add_dependency "dry-core", "~> 1.0", "< 2"
   spec.add_dependency "dry-transformer", "~> 1.0", "< 2"
   spec.add_dependency "concurrent-ruby", "~> 1.0"
 

lib/hanami/utils/callbacks.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "concurrent/array"
+require "dry/core"
 
 module Hanami
   module Utils
@@ -14,6 +15,8 @@ module Callbacks
       # @since 0.1.0
       # @private
       class Chain
+        include Dry.Equalizer(:chain)
+
         # Returns a new chain
         #
         # @return [Hanami::Utils::Callbacks::Chain]
@@ -235,6 +238,8 @@ def self.fabricate(callback)
       # @since 0.1.0
       # @api private
       class Callback
+        include Dry.Equalizer(:callback)
+
         # @api private
         attr_reader :callback
 

spec/unit/hanami/utils/callbacks_spec.rb

@@ -282,6 +282,17 @@ def set_article(params) # rubocop:disable Naming/AccessorMethodName
       expect {  @chain.append :authenticate! }.to raise_error RuntimeError
     end
   end
+
+  describe "#==" do
+    it "is equal to another chain based on its contents" do
+      @chain.append :callback_a, :callback_b
+
+      other = @chain.class.new
+      other.append :callback_a, :callback_b
+
+      expect(@chain).to eq other
+    end
+  end
 end
 
 RSpec.describe Hanami::Utils::Callbacks::Factory do