1 files changed, 88 insertions, 0 deletions
diff --git a/test/ruby/test_alias.rb b/test/ruby/test_alias.rb
index 271d552bf5..539cd49488 100644
--- a/test/ruby/test_alias.rb
+++ b/test/ruby/test_alias.rb
@@ -253,4 +253,92 @@ class TestAlias < Test::Unit::TestCase
     assert_equal(:foo, k.instance_method(:bar).original_name)
     assert_equal(:foo, name)
   end
+
+  def test_alias_suppressing_redefinition
+    assert_in_out_err(%w[-w], "#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      class A
+        def foo; end
+        alias foo foo
+        def foo; end
+      end
+    end;
+  end
+
+  class C2
+    public :system
+    alias_method :bar, :system
+    alias_method :system, :bar
+  end
+
+  def test_zsuper_alias_visibility
+    assert(C2.new.respond_to?(:system))
+  end
+
+  def test_alias_memory_leak
+    assert_no_memory_leak([], "#{<<~"begin;"}", "#{<<~'end;'}", rss: true)
+    begin;
+      class A
+        500.times do
+          1000.times do |i|
+            define_method(:"foo_#{i}") {}
+
+            alias :"foo_#{i}" :"foo_#{i}"
+
+            remove_method :"foo_#{i}"
+          end
+          GC.start
+        end
+      end
+    end;
+  end
+
+  def test_alias_complemented_method
+    assert_in_out_err(%w[-w], "#{<<~"begin;"}\n#{<<~'end;'}")
+    begin;
+      module M
+        def foo = 1
+        self.extend M
+      end
+
+      3.times{|i|
+        module M
+          alias foo2 foo
+          remove_method :foo
+          def foo = 2
+        ensure
+          remove_method :foo
+          alias foo foo2
+          remove_method :foo2
+        end
+
+        M.foo
+
+        original_foo = M.method(:foo)
+
+        M.class_eval do
+          remove_method :foo
+          def foo = 3
+        end
+
+        M.class_eval do
+          remove_method :foo
+          define_method :foo, original_foo
+        end
+      }
+    end;
+  end
+
+  def test_undef_method_error_message_with_zsuper_method
+    modules = [
+      Module.new { private :class },
+      Module.new { prepend Module.new { private :class } },
+    ]
+    message = "undefined method 'class' for module '%s'"
+    modules.each do |mod|
+      assert_raise_with_message(NameError, message % mod) do
+        mod.alias_method :xyz, :class
+      end
+    end
+  end
 end