Did a bit of unit test hacking while on the plane last night. Just
checked in some pretty good early results. We are still bound by JUnit
3 lifecycle simplicity and have to use static singletons, still I was
able to build a little framework for dependency injection into the
test cases, with access to the new DI Cayenne stack. Underneath that
is an old CayenneResources singleton that loads DB connection,
generates the schema, etc...
Still the unit test "frontend" is now drastically different (see e.g.
DataContextEJBQLConditionsTest, one of the few tests that I switched).
Tests extending DICase (or its subclass - ServerCase) can use @Inject
annotations to get access to the interesting parts of the stack being
tested (in 90% of cases that I converted so far this would be
ObjectContext and DBHelper) in a clean manner that does not obfuscate
the test purpose. I also replaced Spring/XML data sets with DBHelper.
So a typical DB-aware test case may look like
DataContextEJBQLConditionsTest:
@UseServerRuntime(ServerCase.TESTMAP_PROJECT)
public class DataContextEJBQLConditionsTest extends ServerCase {
@Inject
protected ObjectContext context;
@Inject
protected DBHelper dbHelper;
protected TableHelper tArtist;
@Override
protected void setUpAfterInjection() throws Exception {
dbHelper.deleteAll("PAINTING_INFO");
...
tArtist = new TableHelper(dbHelper, "ARTIST");
tArtist.setColumns("ARTIST_ID", "ARTIST_NAME");
...
}
protected void createDataSetXYZ() throws Exception {
tArtist.insert(33001, "B");
tArtist.insert(33002, "A");
tArtist.insert(33003, "D");
tPainting.insert(33009, 33001, "X", 5000);
tPainting.insert(33010, 33001, "Y", 5000);
tPainting.insert(33011, 33002, "Z", 5000);
}
public void testSomething() throws Exception {
createDataSetXYZ();
// normal unit test goes here
...
}
It is much cleaner than what we had before at the unit test level at
the expense of a few trivial DI providers in the DI backend.
In general I feel like the Cayenne DI container is a cool little piece
of technology that will take us pretty far in many areas of the
framework. It is still only 36K in size and has simplicity as its main
design paradigm. The only major feature that it is missing compared to
the other guys is method interception, and we can add that down the
road if we feel compelled to have it for Cayenne uses.
Cheers,
Andrus
