Add specs for Struct and Data initialize with empty kwargs

See jruby#9214 and jruby#9224.

Author: headius

spec/ruby/core/data/fixtures/classes.rb

@@ -1,13 +1,20 @@
 module DataSpecs
   if Data.respond_to?(:define)
     Measure = Data.define(:amount, :unit)
+    Single = Data.define(:value)
 
     class MeasureWithOverriddenName < Measure
       def self.name
         "A"
       end
     end
 
+    class SingleWithOverriddenName < Single
+      def self.name
+        "A"
+      end
+    end
+
     class DataSubclass < Data; end
 
     MeasureSubclass = Class.new(Measure) do

spec/ruby/core/data/initialize_spec.rb

@@ -37,6 +37,17 @@
     data.unit.should == "km"
   end
 
+  it "accepts positional arguments with empty keyword arguments" do
+    data = DataSpecs::Single.new(42, **{})
+
+    data.value.should == 42
+
+    data = DataSpecs::Measure.new(42, "km", **{})
+
+    data.amount.should == 42
+    data.unit.should == "km"
+  end
+
   it "raises ArgumentError if no arguments are given" do
     -> {
       DataSpecs::Measure.new
@@ -111,6 +122,17 @@ def initialize(*, **)
       ScratchPad.recorded.should == [:initialize, [], {amount: 42, unit: "m"}]
     end
 
+      it "accepts positional arguments with empty keyword arguments" do
+        data = DataSpecs::SingleWithOverriddenName.new(42, **{})
+
+        data.value.should == 42
+
+        data = DataSpecs::MeasureWithOverriddenName.new(42, "km", **{})
+
+        data.amount.should == 42
+        data.unit.should == "km"
+      end
+
     # See https://github.com/ruby/psych/pull/765
     it "can be deserialized by calling Data.instance_method(:initialize)" do
       d1 = DataSpecs::Area.new(width: 2, height: 3)

spec/ruby/core/struct/fixtures/classes.rb

@@ -3,6 +3,7 @@ module StructClasses
   class Apple < Struct; end
 
   Ruby = Struct.new(:version, :platform)
+  Single = Struct.new(:value)
 
   Car = Struct.new(:make, :model, :year)
 

spec/ruby/core/struct/initialize_spec.rb

@@ -48,4 +48,15 @@
     positional_args.version.should == keyword_args.version
     positional_args.platform.should == keyword_args.platform
   end
+
+  it "accepts positional arguments with empty keyword arguments" do
+    data = StructClasses::Single.new(42, **{})
+
+    data.value.should == 42
+
+    data = StructClasses::Ruby.new("3.2", "OS", **{})
+
+    data.version.should == "3.2"
+    data.platform.should == "OS"
+  end
 end