Add StructClass#keyword_init?

Author: moste00

spec/ruby/core/struct/keyword_init_spec.rb

@@ -17,5 +17,24 @@
       struct = Struct.new(:arg)
       struct.keyword_init?.should be_nil
     end
+
+    it "returns nil for a struct that does specify keyword_init to be nil" do
+      struct = Struct.new(:arg,keyword_init: nil)
+      struct.keyword_init?.should be_nil
+    end
+
+    it "returns true or false for truthy values in general, not just true" do
+      struct = Struct.new(:arg,keyword_init: 1)
+      struct.keyword_init?.should be_true
+
+      struct = Struct.new(:arg,keyword_init: "")
+      struct.keyword_init?.should be_true
+
+      struct = Struct.new(:arg,keyword_init: [])
+      struct.keyword_init?.should be_true
+
+      struct = Struct.new(:arg,keyword_init: {})
+      struct.keyword_init?.should be_true
+    end
   end
 end

spec/tags/core/struct/keyword_init_tags.txt

@@ -33,7 +33,7 @@ class << self
     alias_method :subclass_new, :new
   end
 
-  def self.new(klass_name, *attrs, keyword_init: false, &block)
+  def self.new(klass_name, *attrs, keyword_init: nil, &block)
     if klass_name
       if Primitive.object_kind_of?(klass_name, Symbol) # Truffle: added to avoid exception and match MRI
         attrs.unshift klass_name
@@ -92,7 +92,15 @@ def self.inspect
 
       const_set :STRUCT_ATTRS, attrs
       const_set :KEYWORD_INIT, keyword_init
-    end
+
+      def self.keyword_init?
+        kw_init = self.const_get(:KEYWORD_INIT)
+        return nil if Primitive.nil?(kw_init)
+
+        Primitive.as_boolean(kw_init)
+      end
+
+      end
 
     const_set klass_name, klass if klass_name