Fixed an error in Ruby 3 when specifying a method that takes keyword …

…arguments, such as event's before hook. (#777)

* Reproduction case added

* Allow keyword arguments to be passed to event before, etc. in Ruby 2.7.1 and above.

* refactoring

lib/aasm/base.rb

@@ -223,7 +223,20 @@ def safely_define_method(klass, method_name, method_definition)
         end
       end
 
-      klass.send(:define_method, method_name, method_definition)
+      klass.send(:define_method, method_name, method_definition).tap do |sym|
+        apply_ruby2_keyword(klass, sym)
+      end
+    end
+
+    def apply_ruby2_keyword(klass, sym)
+      if RUBY_VERSION >= '2.7.1'
+        if klass.instance_method(sym).parameters.find { |type, _| type.to_s.start_with?('rest') }
+          # If there is a place where you are receiving in *args, do ruby2_keywords.
+          klass.module_eval do
+            ruby2_keywords sym
+          end
+        end
+      end
     end
 
     def namespace?

spec/models/event_with_keyword_arguments.rb

@@ -0,0 +1,16 @@
+class EventWithKeywordArguments
+  include AASM
+
+  aasm do
+    state :open, :initial => true, :column => :status
+    state :closed
+
+    event :close do
+      before :_before_close
+      transitions from: :open, to: :closed
+    end
+  end
+
+  def _before_close(key:)
+  end
+end

spec/unit/event_with_keyword_arguments_spec.rb

@@ -0,0 +1,10 @@
+require 'spec_helper'
+
+describe EventWithKeywordArguments do
+  let(:example) { EventWithKeywordArguments.new }
+  describe 'enable keyword arguments' do
+    it 'should be executed correctly that method registered by "before hooks" for events with keyword arguments.' do
+      expect(example.close(key: 1)).to be_truthy
+    end
+  end
+end