Improve refine+super tests: add more corner cases & check the whole super chain

Author: ssnickolay

spec/ruby/core/module/fixtures/refine.rb

@@ -3,6 +3,10 @@ class ClassWithFoo
     def foo; "foo" end
   end
 
+  class ClassWithSuperFoo
+    def foo; [:C] end
+  end
+
   module PrependedModule
     def foo; "foo from prepended module"; end
   end
@@ -11,7 +15,9 @@ module IncludedModule
     def foo; "foo from included module"; end
   end
 
-  def self.build_refined_class
-    Class.new(ClassWithFoo)
+  def self.build_refined_class(for_super: false)
+    return Class.new(ClassWithSuperFoo) if for_super
+
+    return Class.new(ClassWithFoo)
   end
 end

spec/ruby/core/module/refine_spec.rb

@@ -731,24 +731,49 @@ def foo
       result.should == "foo"
     end
 
+    it "looks in the refined class from included module" do
+      refined_class = ModuleSpecs.build_refined_class(for_super: true)
+
+      a = Module.new do
+        def foo
+           [:A] + super
+        end
+      end
+
+      refinement = Module.new do
+        refine refined_class do
+          include a
+        end
+      end
+
+      result = nil
+      Module.new do
+        using refinement
+
+        result = refined_class.new.foo
+      end
+
+      result.should == [:A, :C]
+    end
+
     # super in a method of a refinement invokes the method in the refined
     # class even if there is another refinement which has been activated
     # in the same context.
-    it "looks in the refined class even if there is another active refinement" do
-      refined_class = ModuleSpecs.build_refined_class
+    it "looks in the refined class first if called from refined method" do
+      refined_class = ModuleSpecs.build_refined_class(for_super: true)
 
       refinement = Module.new do
         refine refined_class do
           def foo
-            "foo from refinement"
+            [:R1]
           end
         end
       end
 
       refinement_with_super = Module.new do
         refine refined_class do
           def foo
-            super
+            [:R2] + super
           end
         end
       end
@@ -760,7 +785,142 @@ def foo
         result = refined_class.new.foo
       end
 
-      result.should == "foo"
+      result.should == [:R2, :C]
+    end
+
+    it "looks only in the refined class even if there is another active refinement" do
+      refined_class = ModuleSpecs.build_refined_class(for_super: true)
+
+      refinement = Module.new do
+        refine refined_class do
+          def bar
+            "you cannot see me from super because I belongs to another active R"
+          end
+        end
+      end
+
+      refinement_with_super = Module.new do
+        refine refined_class do
+          def bar
+            super
+          end
+        end
+      end
+
+
+      Module.new do
+        using refinement
+        using refinement_with_super
+        -> {
+          refined_class.new.bar
+        }.should raise_error(NoMethodError)
+      end
+    end
+
+    it "does't have access to refinement from included module" do
+      refined_class = ModuleSpecs.build_refined_class
+
+      a = Module.new do
+        def foo
+          super + bar
+        end
+      end
+
+      refinement = Module.new do
+        refine refined_class do
+          include a
+
+          def bar
+            "bar is not seen from A methods"
+          end
+        end
+      end
+
+
+      Module.new do
+        using refinement
+        -> {
+          refined_class.new.foo
+        }.should raise_error(NameError)
+      end
+    end
+
+    # https://bugs.ruby-lang.org/issues/16977
+    it "looks in the another active refinement if super called from included modules" do
+      refined_class = ModuleSpecs.build_refined_class(for_super: true)
+
+      a = Module.new do
+        def foo
+          [:A] + super
+        end
+      end
+
+      b = Module.new do
+        def foo
+          [:B] + super
+        end
+      end
+
+      refinement = Module.new do
+        refine refined_class do
+          include a
+        end
+      end
+
+      refinement1 = Module.new do
+        refine refined_class do
+          include b
+        end
+      end
+
+      result = nil
+      Module.new do
+        using refinement
+        using refinement1
+        result = refined_class.new.foo
+      end
+
+      result.should == [:B, :A, :C]
+    end
+
+    it "looks in the current active refinement from included modules" do
+      refined_class = ModuleSpecs.build_refined_class(for_super: true)
+
+      a = Module.new do
+        def foo
+          [:A] + super
+        end
+      end
+
+      b = Module.new do
+        def foo
+          [:B] + super
+        end
+      end
+
+      refinement = Module.new do
+        refine refined_class do
+          def foo
+            [:LAST] + super
+          end
+        end
+      end
+
+      refinement1 = Module.new do
+        refine refined_class do
+          include a
+          include b
+        end
+      end
+
+      result = nil
+      Module.new do
+        using refinement
+        using refinement1
+        result = refined_class.new.foo
+      end
+
+      result.should == [:B, :A, :LAST, :C]
     end
   end