Rockhopper Blog

Let’s say you’re using JUnit 4 and the Spring Testing classes (the 2.5+ versions) for your unit tests. You can specify parameters as shown in the TransactionConfiguration annotation as shown in this example. But you can also get away with leaving them out in a nod to the uberhip Convention Over Configuration gods as shown in ContextConfigurations

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
@TransactionConfiguration(transactionManager = "transactionManager", defaultRollback = true)
@Transactional
public class UserServiceTest extends
AbstractTransactionalJUnit4SpringContextTests {

So here the context will be loaded by classname-context.xml (e.g. UserServiceTest-context.xml) in the same package as the test class. Cool! You can save your precious digits from typing a few characters.

Let’s say you have unit tests for the persistence layer too. So you have another config file named UserDAOTest-context.xml. And so on for all your other domain classes. Lots of config files that change only a little.

Maybe one has

<aop:advisor pointcut="execution(* *..Service+.*(..))"
advice-ref="txAdvice" />

and another has

<aop:advisor pointcut="execution(* *..DAO+.*(..))"
advice-ref="txAdvice" />

You’re also all wet. There is nothing DRY about this. You are repeating many things with the possibility of missing one. Case in point:
I decided to try to define the datasource like this:

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close" p:driverClassName="org.hsqldb.jdbcDriver"
p:url="jdbc:hsqldb:hsql://localhost:9001/testdb" p:username="sa"
p:password="" />

instead of like this:

<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource"
p:driverClassName="org.hsqldb.jdbcDriver" p:url="jdbc:hsqldb:hsql://localhost:9001/testdb"
p:username="sa" p:password="" />

Small trivial thing right? Except that I missed changing it in one of the config files. Well, what happens to the transaction rollback? Since I’m using AbstractTransactionalJUnit4SpringContextTests I want the junk I shoved into the DB in the @Before method (within the transaction) to be rolled back after the test method. Nope. Ain’t gonna happen. Do a check in @BeforeTransaction and verify in @AfterTransaction and you’ll see. But first you’ll waste a few hours tracking it down thinking the real problem is in one of those Spring XML/Annotation hell holes.

But what would happen if you decided to be unhip and say screw CoC in this case (avoiding a CoC up)?
Something like this:

@ContextConfiguration(locations = { "classpath:com/rockhoppertech/example/test-context.xml" })

OMG you had to type more. And that’s so declasse!
But then you wouldn’t have problems like I just described and you wouldn’t be repeating yourself all over the place like rainman.

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