Raises exception instead of emitting warning.

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+
+jobs:
+  tests:
+    name: Tests
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby-version: ['3.0', '3.2']
+
+    steps:
+    - name: Check out repository
+      uses: actions/checkout@v2
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby-version }}
+        bundler: 2.3
+        bundler-cache: true
+      env:
+        BUNDLE_GITHUB__COM: ${{ secrets.BUNDLE_GITHUB__COM }}:x-oauth-basic
+    - name: Run tests
+      run: bundle exec rake

.gitignore

@@ -3,7 +3,6 @@
 .bundle
 .config
 .yardoc
-Gemfile.lock
 InstalledFiles
 _yardoc
 coverage

Gemfile.lock

@@ -0,0 +1,24 @@
+PATH
+  remote: .
+  specs:
+    memoist (0.16.0)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    benchmark-ips (2.11.0)
+    minitest (5.18.0)
+    rake (13.0.6)
+
+PLATFORMS
+  x86_64-linux
+
+DEPENDENCIES
+  benchmark-ips
+  bundler
+  memoist!
+  minitest (~> 5.10)
+  rake
+
+BUNDLED WITH
+   2.4.3

lib/memoist.rb

@@ -50,11 +50,11 @@ def self.escape_punctuation(string)
     string
   end
 
-  def self.memoist_eval(klass, *args, &block)
+  def self.memoist_eval(klass, *args, **kwargs, &block)
     if klass.respond_to?(:class_eval)
-      klass.class_eval(*args, &block)
+      klass.class_eval(*args, **kwargs, &block)
     else
-      klass.singleton_class.class_eval(*args, &block)
+      klass.singleton_class.class_eval(*args, **kwargs, &block)
     end
   end
 
@@ -132,8 +132,9 @@ def memoize(*method_names)
         include InstanceMethods
 
         if method_defined?(unmemoized_method)
-          warn "Already memoized #{method_name}"
-          return
+          default = "AnIdentifier"
+          suggestion = respond_to?(:name) ? name || default : default
+          raise "Already memoized :#{method_name}. Try `memoize :#{method_name}, identifier: '#{suggestion}'` or use `@#{method_name} ||= compute` pattern instead."
         end
         alias_method unmemoized_method, method_name
 
@@ -203,21 +204,21 @@ def #{method_name}(reload = false)
           # end
 
           module_eval <<-EOS, __FILE__, __LINE__ + 1
-            def #{method_name}(*args)
+            def #{method_name}(*args, **kwargs)
               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))
+              skip_cache = reload || !(instance_variable_defined?(#{memoized_ivar.inspect}) && #{memoized_ivar} && #{memoized_ivar}.has_key?(args+kwargs.to_a))
               set_cache = skip_cache && !frozen?
 
               if skip_cache
-                value = #{unmemoized_method}(*args)
+                value = #{unmemoized_method}(*args, **kwargs)
               else
-                value = #{memoized_ivar}[args]
+                value = #{memoized_ivar}[args+kwargs.to_a]
               end
 
               if set_cache
                 #{memoized_ivar} ||= {}
-                #{memoized_ivar}[args] = value
+                #{memoized_ivar}[args+kwargs.to_a] = value
               end
 
               value

test/memoist_test.rb

@@ -87,6 +87,26 @@ def update_attributes_calls
       @counter.count(:update_attributes)
     end
 
+    def do_with_special(_regular = 10, special_one: true, special_two: true)
+      @counter.call(:do_with_special)
+      true
+    end
+    memoize :do_with_special
+
+    def do_with_special_calls
+      @counter.count(:do_with_special)
+    end
+
+    def format_metadata(metadata)
+      @counter.call(:format_metadata)
+      "#{metadata[:grade]}: #{metadata[:comment]}"
+    end
+    memoize :format_metadata
+
+    def format_metadata_calls
+      @counter.count(:format_metadata)
+    end
+
     protected
 
     def memoize_protected_test
@@ -265,6 +285,35 @@ def test_memoize_with_options_hash
     assert_equal 4, @person.update_attributes_calls
   end
 
+  def test_memoize_with_kwargs
+    assert_equal true, @person.do_with_special(1, special_one: true)
+    assert_equal 1, @person.do_with_special_calls
+
+    3.times { assert_equal true, @person.do_with_special(1, special_one: true) }
+    assert_equal 1, @person.do_with_special_calls
+
+    assert_equal true, @person.do_with_special(2)
+    assert_equal 2, @person.do_with_special_calls
+
+    assert_equal true, @person.do_with_special(1, special_one: false)
+    assert_equal 3, @person.do_with_special_calls
+
+    assert_equal true, @person.do_with_special(1, special_two: false)
+    assert_equal 4, @person.do_with_special_calls
+  end
+
+  def test_memoize_with_hash_for_ruby3
+    metadata = { grade: 42, comment: 'The meaning.' }
+    assert_equal '42: The meaning.', @person.format_metadata(metadata)
+    assert_equal 1, @person.format_metadata_calls
+
+    assert_equal '42: The meaning.', @person.format_metadata(metadata)
+    assert_equal 1, @person.format_metadata_calls
+
+    assert_equal '44: The name.', @person.format_metadata({ grade: 44, comment: 'The name.'})
+    assert_equal 2, @person.format_metadata_calls
+  end
+
   def test_memoization_with_punctuation
     assert_equal true, @person.name?
 
@@ -348,7 +397,7 @@ def test_all_memoized_structs
     # Student < Person   memoize :name, :identifier => :student
     # Teacher < Person   memoize :seniority
 
-    expected = %w[age is_developer? memoize_protected_test name name? sleep update update_attributes]
+    expected = %w[age do_with_special format_metadata is_developer? memoize_protected_test name name? sleep update update_attributes]
     structs = Person.all_memoized_structs
     assert_equal expected, structs.collect(&:memoized_method).collect(&:to_s).sort
     assert_equal '@_memoized_name', structs.detect { |s| s.memoized_method == :name }.ivar
@@ -547,4 +596,35 @@ def test_private_method_memoization
     assert_equal 'Yes', person.send(:is_developer?)
     assert_equal 1, person.is_developer_calls
   end
+
+  def test_exception_when_subclass_without_identifier
+    err = assert_raises(StandardError) do
+      Class.new(Person) do
+        def self.name
+          "Staff"
+        end
+        def name
+          'Overwritten'
+        end
+        memoize :name
+      end
+    end
+    assert_equal(
+      "Already memoized :name. Try `memoize :name, identifier: 'Staff'` or use `@name ||= compute` pattern instead.",
+      err.message
+    )
+
+    err = assert_raises(StandardError) do
+      Class.new(Person) do
+        def name
+          'Overwritten'
+        end
+        memoize :name
+      end
+    end
+    assert_equal(
+      "Already memoized :name. Try `memoize :name, identifier: 'AnIdentifier'` or use `@name ||= compute` pattern instead.",
+      err.message
+    )
+  end
 end