method
public_method_defined?

public_method_defined?(p1)
public
Returns true if the named public method is defined by mod (or its included modules and, if mod is a class, its ancestors).
module A def method1() end end class B protected def method2() end end class C < B include A def method3() end end A.method_defined? :method1 #=> true C.public_method_defined? "method1" #=> true C.public_method_defined? "method2" #=> false C.method_defined? "method2" #=> true