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Posted on November 19th, 2006
Last week, I was onsite with a customer, and we were discussing Test-Driven Development. Actually, we were discussing the Unit Testing features of Team System, but since a lot of the books talk about TDD with the Unit Tests, the conversation wandered into it.
To talk about it, I whipped out the bowling example. I fired up Visual Studio, we created a project and a test project, and started writing tests. We got through the first two tests they came up with (scoring for all 0s, and scoring for all 2s) pretty easily. Then we came to the spare test.
Generally the spare test leads to some refactoring of a simple class to hold the rolls from a frame, and whether it is a spare or a strike. Then, in the score, we loop over the frame collection to generate the score. It always seemed like a big step to me, but I wasn’t sure how to make it smaller.
Turns out I just need to get my head out of OO. After we wrote the test, the people I was with came up with a simple solution to make the test pass. Let’s show it in Ruby (just to give me an excuse to jump over to Ruby). We’ll say we already have the following tests passing:
require 'test/unit'
require 'Game'
class GameTest < Test::Unit::TestCase
def test_works
assert(true)
end
def test_all_0s_scores_0
game = Game.new
10.times do
game.roll(0,0)
end
assert_equal(0, game.score)
end
def test_all_2s_scores_40
game = Game.new
10.times do
game.roll(2,2)
end
assert_equal(40, game.score)
end
end
with this class:
class Game
attr_reader :score
def initialize
@score = 0
end
def roll(roll1, roll2)
@score = @score + roll1 + roll2
end
end
We now add the test for spares:
def test_first_spare_rest_2s_scores_48
game = Game.new
game.roll(8,2)
9.times do
game.roll(2,2)
end
assert_equal(48, game.score)
end
which fails with Test::Unit::AssertionFailedError: <48> expected but was <46>.
As I mentioned before, often times here I would jump to a Frame class or something similar, but this team proposed a flag in Game to know if the last frame was a spare, and then add the roll appropriately. In this case it would look like:
class Game
attr_reader :score
def initialize
@score = 0
@last_frame_spare = false;
end
def roll(roll1, roll2)
if(@last_frame_spare)
@score = @score + roll1
end
@score = @score + roll1 + roll2
if (roll1 + roll2) == 10
@last_frame_spare = true
else
@last_frame_spare = false
end
end
end
Which looks a little klunky, but is TSTTCPW. More importantly, it passes our test.
This week I’m going to take a closer look and see how far I can push this. I can see interesting problems when we get to strikes with strikes, but I’m going to push that off for now.
Posted on November 10th, 2006
Last night I was chatting with a good friend of mine in D.C. and he said that he was reading through this site, and saw stuff about Ruby, and Agile, and TDD, and then, Microsoft, Microsoft, Microsoft, Microsoft.
Well, duh. ;)
Actually, yes, I’m sure that this blog will have more Microsoft stuff than it did before. Now that I’m working for, as my friend called it, the devil, I’m able to see that people want to do Agile stuff with our tools, but it isn’t always appararent (or possible in some cases) to do it.
But not to fear. I doubt there will be much Java content, since I’m not using it day to day anymore, but I still use Ruby, and still will be playing with other dynamic languages, so there will be content on that as well.
In other words, I haven’t forgotten my roots. Software moves too fast to do that.
Posted on November 3rd, 2006
I’ve been playing around with VS2005 and Team Foundation Server. Well, I’ve been reading several books on it, and getting my systems set up for it. I got Team Foundation Server (TFS – the Source Control portion) installed on a Virtual Machine, got Visual Studio (both the Dev and Tester) versions installed on another machine, and was ready to create my first project in TFS.
Except…
Where the heck is Team Explorer? Team Explorer is the main tool used to access TFS, and according to my books, when you install it you can access it directly from VS. Except that the book doesn’t say when or how to install it.
So I look through all my media, and can’t seem to find it on any of the VS install DVDs. I finally look at, um, an internet search site and find Rob Caron’s post entitled “Where is Team Explorer?”.
His post turned out to be a little off – they did change the folder for Team Explorer when TFS went to manufacturing. So, to install Team Explorer, fire up your TFS DVD, go to the tfc directory, and run Setup from there.
Woohoo. Let’s see if I can get a project going now!