Add instance_methods to class generated by DelegateClass

Also, make DelegateClass.instance_method fallback to superclass.

Fixes [Bug #16982]

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/delegate.rb b/lib/delegate.rb
index d6fb90bdbf..a1fded6425 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -422,6 +422,21 @@ def DelegateClass(superclass, &block)
   klass.define_singleton_method :protected_instance_methods do |all=true|
     super(all) | superclass.protected_instance_methods
   end
+  klass.define_singleton_method :instance_methods do |all=true|
+    super(all) | superclass.instance_methods
+  end
+  klass.define_singleton_method :public_instance_method do |name|
+    super(name)
+  rescue NameError
+    raise unless self.public_instance_methods.include?(name)
+    superclass.public_instance_method(name)
+  end
+  klass.define_singleton_method :instance_method do |name|
+    super(name)
+  rescue NameError
+    raise unless self.instance_methods.include?(name)
+    superclass.instance_method(name)
+  end
   klass.module_eval(&block) if block
   return klass
 end