= EdgeCase Ruby Koans
The Ruby Koans walk you along the path to enlightenment in order to learn Ruby.
The goal is to learn the Ruby language, syntax, structure, and some common
functions and libraries. We also teach you culture. Testing is not just something we
pay lip service to, but something we live. It is essential in your quest to learn
and do great things in the language.
== The Structure
The koans are broken out into areas by file, hashes are covered in about_hashes.rb,
modules are introduced in about_modules.rb, etc. They are presented in order in the
path_to_enlightenment.rb file.
Each koan builds up your knowledge of Ruby and builds upon itself. It will stop at
the first place you need to correct.
Some koans simply need to have the correct answer substituted for an incorrect one.
Some, however, require you to supply your own answer. If you see the method +__+ (a
double underscore) listed, it is a hint to you to supply your own code in order to
make it work correctly.
== Installing Ruby
If you do not have Ruby setup, please visit http://ruby-lang.org/en/downloads/ for
operating specific instructions. In order to run this you need ruby and rake
installed. To check the installations simply type:
*nix platforms from any terminal window:
[~] $ ruby --version
[~] $ rake --version
Windows from the command prompt (cmd.exe)
c:\ruby --version
c:\rake --version
Any response for Ruby with a version number greater than 1.8 is fine (should be
around 1.8.6 or more). Any version of rake will do.
== The Path To Enlightenment
You can run the tests through rake or by calling the file itself (rake is the
recommended way to run them as we might build more functionality into this task).
*nix platforms, from the koans directory
[ruby_koans] $ rake # runs the default target :walk_the_path
[ruby_koans] $ ruby path_to_enlightenment.rb # simply call the file directly
Windows is the same thing
c:\ruby_koans\rake # runs the default target :walk_the_path
c:\ruby_koans\ruby path_to_enlightenment.rb # simply call the file directly
=== Red, Green, Refactor
In test-driven development the mantra has always been, red, green, refactor. Write a
failing test and run it (red), make the test pass (green), then refactor it (that is
look at the code and see if you can make it any better. In this case you will need
to run the koan and see it fail (red), make the test pass (green), then take a
moment and reflect upon the test to see what it is teaching you and improve the
code to better communicate its intent (refactor).
The very first time you run it you will see the following output:
[ ruby_koans ] $ rake
(in /Users/person/dev/ruby_koans)
cd koans
Thinking AboutAsserts
test_assert_truth has damaged your karma.
You have not yet reached enlightenment ...
<false> is not true.
Please meditate on the following code:
./about_asserts.rb:10:in `test_assert_truth'
path_to_enlightenment.rb:27
mountains are merely mountains
You have come to your first stage. If you notice it is telling you where to look for
the first solution:
Please meditate on the following code:
./about_asserts.rb:10:in `test_assert_truth'
path_to_enlightenment.rb:27
We then open up the about_asserts.rb file and look at the first test:
# We shall contemplate truth by testing reality, via asserts.
def test_assert_truth
assert false # This should be true
end
We then change the +false+ to +true+ and run the test again. After you are
done, think about what you are learning. In this case, ignore everything except
the method name (+test_assert_truth+) and the parts inside the method (everything
before the +end+).
In this case the goal is for you to see that if you pass a value to the +assert+
method, it will either ensure it is +true+ and continue on, or fail if in fact
the statement is +false+.
== Inspiration
A special thanks to Mike Clark and Ara Howard for inspiring this
project. Mike Clark wrote an excellent blog post about learning Ruby
through unit testing. This sparked an idea that has taken a bit to
solidify, that of bringing new rubyists into the community through
testing. Ara Howard then gave us the idea for the Koans in his ruby
quiz entry on Meta Koans (a must for any rubyist wanting to improve
their skills). Also, "The Little Lisper" taught us all the value of
the short questions/simple answers style of learning.
Mike Clark's post :: http://www.clarkware.com/cgi/blosxom/2005/03/18
Meta Koans :: http://rubyquiz.com/quiz67.html
The Little Lisper :: http://www.amazon.com/Little-LISPer-Third-Daniel-Friedman/dp/0023397632
== Other Resources
The Ruby Language :: http://ruby-lang.org
Try Ruby in your browser :: http://tryruby.org
Dave Thomas' introduction to Ruby Programming Ruby (the Pick Axe) :: http://pragprog.com/titles/ruby/programming-ruby
Brian Marick's fantastic guide for beginners Everyday Scripting with Ruby :: http://pragprog.com/titles/bmsft/everyday-scripting-with-ruby
= Other stuff
Author :: Jim Weirich <jim@weirichhouse.org>
Author :: Joe O'Brien <joe@edgecase.com>
Issue Tracker :: http://www.pivotaltracker.com/projects/48111
Requires :: Ruby 1.8.x or later and Rake (any recent version)
