UsingEclEmmatoWriteBetterUnitTests-创新互联

转载：http://ericanderson.us/2008/05/08/using-eclemma-to-write-better-unit-tests/

If you don’t already write unit tests you should be. (Hey, why aren’t you writing unit tests?) Unit testing has so many benefits and the upfront developer cost to write some unit tests can pay huge dividends later when you aren’t spending time debugging broken code nor attempting to save face due to clueless mistakes. You can also use them as a contract to the expectations of your implementations.

So, assuming you have some unit tests, how useful are they if they don’t test everything? At some level you will want to have a good idea that you’re testing everything. (NOTE: I mean everything really important. Writing perfect 100% coverage like this would likely be too expensive for the entire codebase.) This is where Emma comes in (and more importantly for us, EclEmma, an Eclipse plugin for Emma). Emma is a code coverage tool which lets you visual which parts of your code get executed during some execution (regular or JUnit).

Lets walk through using EclEmma to ensure that we have adequate testing being done. Lets test the following two classes.

GuessTheNumber.java: