From: Hemant Kumar <gethemant@...>
Date: 2007-01-03T22:30:58+09:00
Subject: Problem in Unit Testing Methods that start new threads

I have a bit of doubt, in Unit Testing Programs that start new threads.
Please have a look at the code below:


class Foobar

  def hello_world
    p "Hello World"
    @thread_status = false
  end

  def new_thread_start
    Thread.new do
      sleep(100)
      @thread_status = true
    end
  end

end

# here goes the lame test case
require "test/unit"

module Test::Unit::Assertions
  def assert_false(t_object,message=nil)
    boolean = !t_object
    full_message = build_message(message,'<?> Object is not
false',boolean)
    assert_block(full_message) { boolean}
  end
end

class TestFoobar < Test::Unit::TestCase
  def setup
    @foo = Foobar.new
    class << @foo
      def ivar var
        instance_variable_get(:"@#{var}")
      end
    end
  end

  def test_hello_world
    @foo.hello_world
    assert_false @foo.ivar(:thread_status)
  end


  def test_new_thread
    # sorry for a bit of not so DRY thingy
    @foo.hello_world
    assert_false @foo.ivar(:thread_status)
    @foo.new_thread_start

    # next assert is true because method was started in a new thread 
    # and control came back immediately, what i would probably want is 
    # to wait here so that i can have proper check on the method and 
    # state of the program, but i am not sure, if that's exactly 
    # approach i should take.

    assert_false @foo.ivar(:thread_status)
  end
end


Now, as someone suggested on IRC, I can do a join and wait for the
thread to finish. But the problem is, I don't exactly have an instance
to the thread, because its managed by a plugin and i am just using the
plugin to do stuff.

Any ideas/suggestions are more than welcome.


gnufied