Add specs for rb_class_get_superclass

Author: andrykonchin

lib/truffle/truffle/cext.rb

@@ -604,6 +604,7 @@ def rb_class_real(ruby_class)
   end
 
   def rb_class_get_superclass(ruby_class)
+    return false unless Primitive.is_a?(ruby_class, Class)
     ruby_class.superclass || false
   end
 

spec/ruby/optional/capi/class_spec.rb

@@ -487,4 +487,16 @@ def obj.some_method() end
       @s.rb_class_real(0).should == 0
     end
   end
+
+  describe "rb_class_get_superclass" do
+    it "returns parent class for a provided class" do
+      a = Class.new
+      @s.rb_class_get_superclass(Class.new(a)).should == a
+    end
+
+    it "returns false when there is no parent class" do
+      @s.rb_class_get_superclass(BasicObject).should == false
+      @s.rb_class_get_superclass(Module.new).should == false
+    end
+  end
 end

spec/ruby/optional/capi/ext/class_spec.c

@@ -79,6 +79,10 @@ static VALUE class_spec_rb_class_real(VALUE self, VALUE object) {
   }
 }
 
+static VALUE class_spec_rb_class_get_superclass(VALUE self, VALUE klass) {
+  return rb_class_get_superclass(klass);
+}
+
 static VALUE class_spec_rb_class_superclass(VALUE self, VALUE klass) {
   return rb_class_superclass(klass);
 }
@@ -160,6 +164,7 @@ void Init_class_spec(void) {
   rb_define_method(cls, "rb_class_new_instance_kw", class_spec_rb_class_new_instance_kw, 2);
 #endif
   rb_define_method(cls, "rb_class_real", class_spec_rb_class_real, 1);
+  rb_define_method(cls, "rb_class_get_superclass", class_spec_rb_class_get_superclass, 1);
   rb_define_method(cls, "rb_class_superclass", class_spec_rb_class_superclass, 1);
   rb_define_method(cls, "rb_cvar_defined", class_spec_cvar_defined, 2);
   rb_define_method(cls, "rb_cvar_get", class_spec_cvar_get, 2);