Working Effectively with Unit Tests Official Launch

Today marks the official release release of Working Effectively with Unit Tests. The book is available in various formats:

• DRM free pdf, epub, & mobi (Kindle) at http://leanpub.com/wewut

• Softcover at http://amzn.com/1503242706

• Kindle edition at http://amzn.com/B00QS2HXUO

I’m very happy with the final version. Michael Feathers wrote a great foreword. I incorporated feedback from dozens of people - some that have been friends for years, and some that I’d never previously met. I can’t say enough great things about http://leanpub.com, and I highly recommend it for getting an idea out there and making it easy to get fast feedback. 

As far as the softcover edition, I had offers from a few major publishers, but in the end none of them would allow me to continue to sell on leanpub at the same time. I strongly considered caving to the demands of the major publishers, but ultimately the ability to create a high quality softcover and make it available on Amazon was too tempting to pass up.

The feedback has been almost universally positive - the reviews are quite solid on goodreads (http://review.wewut.com). I believe the book provides specific, concise direction for effective Unit Testing, and I hope it helps increase the quality of the unit tests found in the wild.

If you'd like to try before you buy, there's a sample available in pdf format or on the web.

Ruby: Testing Private Methods

Jason Rudolph recently wrote about Testing Private Methods in Ruby. Before I continue, it's probably a good idea to note that I rarely test private methods. I prefer to test through the public API. However, there are times when life is easier if you write a few tests for a private method or two.

The solution highlighted by Jason (original implementation from Evan Phoenix) is nice from a maintainability perspective since it encapsulates changing the behavior of the class within the test. However, it's a bit verbose for my taste.

Reading the entry I couldn't help but think that gaining temporary access to a private method for testing seems like something that can be handled by a general solution instead.

Here's how I would have solved the problem.

require 'rubygems'
require 'dust'
require 'test/unit'

class Ninja
  private
  def kill(num_victims)
    "#{num_victims} victims are no longer with us."
  end
end

class Class
  def publicize_methods
    saved_private_instance_methods = self.private_instance_methods
    self.class_eval { public *saved_private_instance_methods }
    yield
    self.class_eval { private *saved_private_instance_methods }
  end
end

unit_tests do
  test "kill returns a murder string" do
    Ninja.publicize_methods do
      assert_equal '3 victims are no longer with us.', Ninja.new.kill(3)
    end
  end
end