tracepoint

test.rb

class TestObj
  def method_missing(method_name, *args)
    if method_name == :works?
      true
    else
      super
    end
  end

  def respond_to_missing?(method_name, include_private = false)
    method_name == :works? || super
  end

  def something_else?
    false
  end
end

TracePoint.new(:a_call) { |tp| puts tp.inspect }.enable do
  TestObj.new.works?
end

# Output:
#<TracePoint:b_call test.rb:19>
#<TracePoint:c_call `new' test.rb:20>
#<TracePoint:c_call `initialize' test.rb:20>
#<TracePoint:call `method_missing' test.rb:2>
#<TracePoint:c_call `==' test.rb:3>