2 files changed, 135 insertions, 0 deletions
diff --git a/spec/ruby/core/module/ruby2_keywords_spec.rb b/spec/ruby/core/module/ruby2_keywords_spec.rb
new file mode 100644
index 0000000000..34c45cb1bc
--- /dev/null
+++ b/spec/ruby/core/module/ruby2_keywords_spec.rb
@@ -0,0 +1,112 @@
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+
+ruby_version_is "2.7" do
+  describe "Module#ruby2_keywords" do
+    it "marks the final hash argument as keyword hash" do
+      obj = Object.new
+
+      obj.singleton_class.class_exec do
+        def foo(*a) a.last end
+        ruby2_keywords :foo
+      end
+
+      last = obj.foo(1, 2, a: "a")
+      Hash.ruby2_keywords_hash?(last).should == true
+    end
+
+    ruby_version_is "2.7" ... "3.0" do
+      it "fixes delegation warnings when calling a method accepting keywords" do
+        obj = Object.new
+
+        obj.singleton_class.class_exec do
+          def foo(*a) bar(*a) end
+          def bar(*a, **b) end
+        end
+
+        -> { obj.foo(1, 2, {a: "a"}) }.should complain(/Using the last argument as keyword parameters is deprecated/)
+
+        obj.singleton_class.class_exec do
+          ruby2_keywords :foo
+        end
+
+        -> { obj.foo(1, 2, {a: "a"}) }.should_not complain
+      end
+    end
+
+    it "returns nil" do
+      obj = Object.new
+
+      obj.singleton_class.class_exec do
+        def foo(*a) end
+
+        ruby2_keywords(:foo).should == nil
+      end
+    end
+
+    it "raises NameError when passed not existing method name" do
+      obj = Object.new
+
+      -> {
+        obj.singleton_class.class_exec do
+          ruby2_keywords :not_existing
+        end
+      }.should raise_error(NameError, /undefined method `not_existing'/)
+    end
+
+    it "acceps String as well" do
+      obj = Object.new
+
+      obj.singleton_class.class_exec do
+        def foo(*a) a.last end
+        ruby2_keywords "foo"
+      end
+
+      last = obj.foo(1, 2, a: "a")
+      Hash.ruby2_keywords_hash?(last).should == true
+    end
+
+    it "raises TypeError when passed not Symbol or String" do
+      obj = Object.new
+
+      -> {
+        obj.singleton_class.class_exec do
+          ruby2_keywords Object.new
+        end
+      }.should raise_error(TypeError, /is not a symbol nor a string/)
+    end
+
+    it "prints warning when a method does not accept argument splat" do
+      obj = Object.new
+      def obj.foo(a, b, c) end
+
+      -> {
+        obj.singleton_class.class_exec do
+          ruby2_keywords :foo
+        end
+      }.should complain(/Skipping set of ruby2_keywords flag for/)
+    end
+
+    it "prints warning when a method accepts keywords" do
+      obj = Object.new
+      def obj.foo(a:, b:) end
+
+      -> {
+        obj.singleton_class.class_exec do
+          ruby2_keywords :foo
+        end
+      }.should complain(/Skipping set of ruby2_keywords flag for/)
+    end
+
+    it "prints warning when a method accepts keyword splat" do
+      obj = Object.new
+      def obj.foo(**a) end
+
+      -> {
+        obj.singleton_class.class_exec do
+          ruby2_keywords :foo
+        end
+      }.should complain(/Skipping set of ruby2_keywords flag for/)
+    end
+  end
+end
diff --git a/spec/ruby/core/module/to_s_spec.rb b/spec/ruby/core/module/to_s_spec.rb
index 29f6ecf726..6b1a615ef9 100644
--- a/spec/ruby/core/module/to_s_spec.rb
+++ b/spec/ruby/core/module/to_s_spec.rb
@@ -42,4 +42,27 @@ describe "Module#to_s" do
     obj = ModuleSpecs::NamedClass.new
     obj.singleton_class.to_s.should =~ /\A#<Class:#<ModuleSpecs::NamedClass:0x\h+>>\z/
   end
+
+  it "always show the refinement name, even if the module is named" do
+    module ModuleSpecs::RefinementInspect
+      R = refine String do
+      end
+    end
+
+    ModuleSpecs::RefinementInspect::R.name.should == 'ModuleSpecs::RefinementInspect::R'
+    ModuleSpecs::RefinementInspect::R.to_s.should == '#<refinement:String@ModuleSpecs::RefinementInspect>'
+  end
+
+  it 'does not call #inspect or #to_s for singleton classes' do
+    klass = Class.new
+    obj = klass.new
+    def obj.to_s
+      "to_s"
+    end
+    def obj.inspect
+      "inspect"
+    end
+    sclass = obj.singleton_class
+    sclass.to_s.should =~ /\A#<Class:#<#{Regexp.escape klass.to_s}:0x\h+>>\z/
+  end
 end