Code Retreat in ThoughtWorks 2012

This time I was in taking a part in Code Retreat organized by London branch of ThoughtWorks and it was awesome !!

I decided to spent half of a day writing code in languages other than Java. I have chosen Groovy, Ruby and C#. I have to say that all sessions went very well. Okay, so let me describe them briefly: 

#session 1: Groovy with no constraints - just a warm up in a language similar to Java.

#session 2: Java and baby steps - this one was very good. The quite nice and neat design was emerging from the code driven by our tests.

#session 3: Ruby and no more than 4 lines of code per method - actually 4 lines of code per method wasn't hard to achieve in Ruby. To be fairly honest, the longest method we had, had literally 2 lines. What's more, Ruby guy, I was pairing with, has shown me some magic in Vim. I thought I knew Vim quite good, however it appeared I am a barely novice :P

#session 4: Java and immutable objects - this was actually quite interesting one, as well. Immutable objects were affecting our design in a way we did not expect, at the very beginning. 

#session 5: Java and no primitives - again another interesting design emerged.

#session 6: C# and tell don't ask (our choice) - that was actually quite a challenge to use only procedures.

All in all, it was very educational, eyes opening and enlightening day. Although there were couple of tricks I learned, I think the most valuable one is related to the way of coping & pasting code. If you really need to do it, do it as below:
- copy & paste the code
- use question marks to denote parts of code you have to amend
- replace question marks with valid code starting from the top

Just to make things clear, let's have a look on a below example:

"Any live cell with fewer than two live neighbours dies, as if caused by under-population."

@Test
public void liveCellWithFewerThanTwoLiveNeighboursDies() {
	int oneNeighbour = 1;
	Cell liveCell = new Cell(ALIVE, oneNeighbour);

	liveCell.tick();

	assertThat(liveCell.getState(), is(equalTo(DEAD)));
}

And here you decided to copy above test in order to tweak it slightly, so that you can get another valid test.

"Any live cell with more than three live neighbours dies, as if by overcrowding."

@Test
public void liveCellWith???NeighboursDies() {
	int ???Neighbour??? = ???;
	Cell liveCell = new Cell(ALIVE, ???Neighbour???);

	liveCell.tick();

	assertThat(liveCell.getState(), is(equalTo(DEAD)));
}

And here is the result:

@Test
public void liveCellWithMoreThanThreeLiveNeighboursDies() {
	int fiveNeighbours = 5;
	Cell liveCell = new Cell(ALIVE, fiveNeighbours);

	liveCell.tick();

	assertThat(liveCell.getState(), is(equalTo(DEAD)));
}

As simple as that, but helps you to avoid silly errors.