Add ruby 3 compatibility.

lib/memoist.rb

@@ -13,6 +13,16 @@ def self.memoized_methods
     end
   end
 
+  def self.extended(extender)
+    Memoist.memoist_eval(extender) do
+      unless singleton_class.method_defined?(:memoized_methods)
+        def self.memoized_methods
+          @_memoized_methods ||= []
+        end
+      end
+    end
+  end
+
   def self.memoized_ivar_for(method_name, identifier = nil)
     "@#{memoized_prefix(identifier)}_#{escape_punctuation(method_name)}"
   end
@@ -59,7 +69,7 @@ def self.memoist_eval(klass, *args, &block)
   end
 
   def self.extract_reload!(method, args)
-    if args.length == method.arity.abs + 1 && (args.last == true || args.last == :reload)
+    if args.length == method.arity.abs + 2 && (args.last == true || args.last == :reload)
       reload = args.pop
     end
     reload
@@ -123,6 +133,9 @@ def clear_structs
 
   def memoize(*method_names)
     identifier = method_names.pop[:identifier] if method_names.last.is_a?(Hash)
+    if method_names.last.is_a?(Hash)
+      identifier = method_names.pop[:identifier]
+    end
 
     method_names.each do |method_name|
       unmemoized_method = Memoist.unmemoized_method_for(method_name, identifier)
@@ -203,14 +216,17 @@ def #{method_name}(reload = false)
           # end
 
           module_eval <<-EOS, __FILE__, __LINE__ + 1
-            def #{method_name}(*args)
+            def #{method_name}(*positioned_args, **named_args)
+              args = [named_args, *positioned_args]
               reload = Memoist.extract_reload!(method(#{unmemoized_method.inspect}), args)
 
               skip_cache = reload || !(instance_variable_defined?(#{memoized_ivar.inspect}) && #{memoized_ivar} && #{memoized_ivar}.has_key?(args))
               set_cache = skip_cache && !frozen?
 
               if skip_cache
-                value = #{unmemoized_method}(*args)
+                named_args, *positioned_args = args
+                positioned_args.pop if !reload.nil? && [true, :reload].include?(positioned_args.last)
+                value = #{unmemoized_method}(*positioned_args, **named_args)
               else
                 value = #{memoized_ivar}[args]
               end

test/memoist/args_test.rb

@@ -0,0 +1,39 @@
+require 'pry-rails'
+require 'test_helper'
+require_relative '../support/named_args_helper'
+
+class MemoistNamedArgsTest < Minitest::Test
+  def test_named_args_class_initialization
+    instance1 = ::NamedArgsHelper.new(a1: 11)
+    instance2 = ::NamedArgsHelper.new(a1: 11)
+
+    refute_same instance1, instance2
+  end
+
+  def test_memoized_object_is_properly_caching_with_named_args
+    instance = ::NamedArgsHelper.new(a1: 11)
+    result1 = instance.calc_with_named_args(a2: 12, a3: 13)
+    _result2 = instance.calc_with_named_args(a2: 13, a3: 13)
+    result3 = instance.calc_with_named_args(a2: 12, a3: 13)
+
+    assert_same result1, result3
+  end
+
+  def test_memoized_object_is_properly_caching_with_positioned_args
+    instance = ::NamedArgsHelper.new(a1: 11)
+    result1 = instance.calc_with_positioned_args(12, 13)
+    _result2 = instance.calc_with_positioned_args(13, 13)
+    result3 = instance.calc_with_positioned_args(12, 13)
+
+    assert_same result1, result3
+  end
+
+  def test_memoized_object_is_properly_caching_with_mixed_args
+    instance = ::NamedArgsHelper.new(a1: 11)
+    result1 = instance.calc_with_mixed_args(12, a3: 13)
+    _result2 = instance.calc_with_mixed_args(13, a3: 13)
+    result3 = instance.calc_with_mixed_args(12, a3: 13)
+
+    assert_same result1, result3
+  end
+end

test/support/named_args_helper.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+require 'memoist'
+
+class NamedArgsHelper
+  extend Memoist
+
+  def initialize(a1:)
+    @a1 = a1
+  end
+
+  def calc_with_named_args(a2:, a3: nil)
+    create_object(a1: a1, a2: a2, a3: a3)
+  end
+  memoize :calc_with_named_args
+
+  def calc_with_positioned_args(a2, a3 = nil)
+    create_object(a1: a1, a2: a2, a3: a3)
+  end
+  memoize :calc_with_positioned_args
+
+  def calc_with_mixed_args(a2, a3: nil)
+    create_object(a1: a1, a2: a2, a3: a3)
+  end
+  memoize :calc_with_mixed_args
+
+  private
+
+  attr_reader :a1
+
+  def create_object(**named_args)
+    OpenStruct.new(**named_args)
+  end
+end