How to invoke all instance methods of a class in Ruby?

Question

I'm currently working on throwing together my own little test method runner script.

I need some way to call all of the methods in a class. When I invoke the run_tests method, my program is stuck in an infinite loop. What is causing this and what are some solutions?

class FadTest < SeleniumTest
  def can_open_page
    @driver.get(@base_url + "/")
    wait_element_present(:link, "DOCTORS")
    @driver.find_element(:link, "DOCTORS").click
    puts "page opened"
  end

  def test_method
    puts "it works"
  end

  def run_tests
    klass = self.class
    klass.instance_methods(false).each do |method|
      klass.instance_method(method).bind(self).call
    end
  end 
end

Answer 1

As mentioned by Wand Maker , run_tests involves recursion. Your code is being executed in the following manner:

1. Find the class of some object
2. Call SomeClass.instance_methods.each {}
3. Once you reach run_tests , you start the iteration over again.
4. Infinite loop -- you never reach the remaining instance methods.

I am not sure how you have designed your tests, so here are a few options to solve the problem

If all tested objects have the class FadTest , you can edit the logic within the iteration, my preferred solution is what the Tin Man suggested

klass.instance_methods(false).each do |method|
  next if method == :run_tests
  # ...
end

Only problem is that you are still scanning the :run_tests element. If you want to remain full proof and not have :run_tests in the array, you can try what Cary Swoveland suggested :

(klass.instance_methods(false) - [:run_tests]).each {}

If the class of the tested object is not FadTest , then I would suggest a rewrite of the method.

def self.run_tests(object)
  klass = object.class
  klass.instance_methods(false).each {}
end

FadTest.run_tests(some_object)