Wednesday, April 20, 2005

What is Wrong with This Code

Managing and assisting a project development is more and more interesting to me nowadays. However, from time to time, I will run into some code that I think worth documenting.

What is wrong with this code in a test case:

public void testShowAddressInvalidCountryCode() {
DomainError e= ErrorMsg.AddressInvalidCountryCode;
String msg = ErrorMsg.showErrorMsg(e,new DomainErrorValue(ErrorMsg.PERMANENT_ADDRESS));
assertTrue(msg!="No error msg");
If you don't see why, let me explain:
  • Don't use negative assertions: Asserting two things not equal is most error-prone. If you assert that a return value NOT equals 0, for example, chances are that this test will still pass, even if a bug is to be introduced in the method making it return 6 instead of 5.
  • Don't use instance comparison: If the method decide to create a new copy for return object, then it is impossible to test. For the example here, if the method innocently construct the message "No error msg" instead of returning the constant, the instance check will render useless.
  • Don't do System.out during test: This will pollute the output in the console and make it useless. If it is anything need to be verified, verify it with assertions. ASH project went a little to the extreme but it has very sound reason.
  • Do test-driven development: Code like this is most likely a symptom of lacking test-driven development.

Friday, April 01, 2005

Happy Apile Fool's Day

On this day, there are two things that I want to mention. Normally I stick this blog to my working experience, but I figure everything has an exception...

GMail bumped up everyone's storage! This is one company that keeps reminding me that you can make things better by making things right. They keep on surprising me in a good way and I just love this company more and more. As a matter of fact, I would have worked for them, if their HR were not so slow on setting up interviews (that was an interesting experience last year, switching my Google HR contact three times in two months), that I ended up running into ThoughtWorks, a company that I should have been working for since year 2000. Even though my job in JBuilder was a great experience, I am sure I can do much better in a company like ThoughtWorks.

ThoughtWorks name was mentioned in a April Fool's webpage (PaiOn Chair). I asked around and didn't hear anyone knows the folks in Cenqua. So if that is the fact, this is a good sign that we are being regarded as THE XP shop, a name that everyone is building for.