proc.c: original arity

* proc.c (rb_mod_method_arity): return original arity of the method if
  aliased because of visibility change, like as Method#arity.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38967 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 37 insertions, 0 deletions

diff --git a/test/-ext-/method/test_arity.rb b/test/-ext-/method/test_arity.rb
new file mode 100644
index 0000000000..79ef23b34f
--- /dev/null
+++ b/test/-ext-/method/test_arity.rb
@@ -0,0 +1,37 @@
+require '-test-/method'
+require 'test/unit'
+
+class TestMethod < Test::Unit::TestCase
+  class TestArity < Test::Unit::TestCase
+    class A
+      def foo0()
+      end
+      def foom1(*a)
+      end
+      def foom2(a,*b)
+      end
+      def foo1(a)
+      end
+      def foo2(a,b)
+      end
+    end
+
+    class B<A
+      private :foo1, :foo2
+    end
+
+    METHODS = {foo0: 0, foo1: 1, foo2: 2, foom1: -1, foom2: -2}
+
+    def test_base
+      METHODS.each do |name, arity|
+        assert_equal(arity, Bug::Method.mod_method_arity(A, name), "A##{name}")
+      end
+    end
+
+    def test_zsuper
+      METHODS.each do |name, arity|
+        assert_equal(arity, Bug::Method.mod_method_arity(B, name), "B##{name}")
+      end
+    end
+  end
+end