Bug #11980: External methods are appearing as instance methods for String

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 2.3.0
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN

[danielpclark (Daniel P. Clark)]

It appears we're having methods creep into the String scope.

"".methods.count
# => 170

defined? "".a
# => nil

def a
 "foo"
end

"".methods.count
# => 171

defined? "".a
# => "method"

"bar".a
# => "foo"

[danielpclark (Daniel P. Clark)]

It's not just String.

Array.instance_method(:a).owner
# => Object

[danielpclark (Daniel P. Clark)]

Those results were from IRB. Here's my results from a Ruby script.

"test_scope_creep.rb"

puts "".methods.count
puts defined? "".a
def a
  "foo"
end
puts "".methods.count
puts defined? "".a
puts String.private_method_defined? :a
puts String.instance_method(:a).owner
puts "".send :a
puts Array.private_method_defined? :a
puts Array.instance_method(:a).owner
puts [].send :a

Output:

170

170

true
Object
foo
true
Object
foo

It appears they are defined as private methods when run via ruby and in irb they run like they're not private methods.

[codetodya (Sumit Mahamuni)]

It's not really a bug.

When you define following method. It is added on Object class. And any class which inherits from Object class will have following method.

You can try calling following method on any class which inherits Object class, you should get same output.

def a
  "foo"
end

[jeremyevans0 (Jeremy Evans)]

• Status changed from Open to Closed