Posterous theme by Cory Watilo

Recursive Erudition


Learn. Teach. Learn.

Test-Driven Learning

You may not have realized it, but learning Ruby is like being attacked by a bunch of ADD Buddhist Monks. They’ll jump into your living room, raving and excited, and do back flips while telling you how Zen and relaxing development should be. It’s weird.

Once we’ve medicated the frenetic relaxation, though, it’s really evident that there a lot of good ideas to be found in this community. The latest that I’ve discovered is Test-Driven Learning.

What this means to me is that I can FINALLY stop writing ‘Hello World’ programs. Languages have print or printf or puts commands—we can stop being thrilled by that now. Ok? Let’s just write Tests! If we can make test Assertions, we can kick the tires of each new piece of language syntax we learn as we learn it without creating silly, baroque programs to host them.

Lets start out by discovering the shortest syntax to use the language’s testing framework. The one built into Ruby is Test::Unit. This is easy in Ruby. You need a ‘require’ line and to subclass the test fixture class. 

require "test/unit"
class TestTest
< Test::Unit::TestCase
def test_tests
assert true
end
end

That’s easy. And now you can assert things. Like ‘true’. Save that in a file, like ‘test.rb’ then execute it with the ruby command line. 

C:\Users\josh\Desktop> ruby test.rb
Loaded suite test_test
Started
.
Finished in 0.001
seconds.
 
1 tests, 1 assertions, 0 failures, 0 errors

From here on out, just start adding ‘assert’ lines as you discover things about Ruby. Since we started with ‘true’, maybe some asserts on Truth would be a good start. I wonder which of these will pass and which will fail? If you know Perl, Javascript, or C# your preconceptions will be different. 

assert true
assert false
assert 'True'
assert ""
assert 0
assert 1

So little code, and now you can curl up with your favorite Ruby howto book and spend a warm afternoon pondering the nature of Truth. Exciting eh? Well calm down! You don’t need to be a crazy Zen guy. Just do some learning.

Resources:

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