How do I test that controllers write correctly to the DB in playframework - jpa

Question

I have a FunctionalTest that tests posting to a controller and then does asserts on the model objects to make sure the controller did it's job, like so:
#Test
public void editUser(){
Logger.debug("Edit user test");
createNewUser();
final User user = User.<User>findAll().get(0);
POST("/ManageUser/save", ImmutableMap.of(
"user.id", user.getId().toString(),
"user.username", "test",
"user.email", "test#example.com",
"user.fullName", "Test Different"
));
User.em().flush();
User.em().clear(); // this is required so that it works on the mem DB
assertEquals(1, User.findAll().size());
assertEquals("Test Different", User.<User>findAll().get(0).fullName);
final User userAfterSave = User.<User>findAll().get(0);
assertFalse("New user should not be admin.", userAfterSave.isAdmin);
}
This passes when I use the mem database
%test.db.url=jdbc:h2:mem:play;MODE=MYSQL;LOCK_MODE=0
However if I switch to mysql
%test.db=mysql://test:test#localhost/test
It fails on the second assert "Failure, expected:<Test [Differen]t> but was:<Test [Tes]t>". So when using mysql the controller doesn't persist the user properly.
What am I missing here, are there some options for transaction control that I need to change for this to work?
The controller just calls user.merge().save() to update the user, is this somehow wrong?

Answer 1

This is because the mem DB is not properly transactional, meaning the test thread gets new data every read. For mysql however the test thread read the user in createNewUser() meaning it's transaction had the previous version. It's not obvious but POST() starts a new thread with a separate transaction. To solve this swap out
User.em().flush();
User.em().clear();
for
JPAPlugin.closeTx(false);
JPAPlugin.startTx(false);
The later starts a new transaction.

Answer 2

Do your search in a separate job to be sure it correctly view the modifications (transaction isolation). Here is an example
private FeedbackType findFeedbackType(final String name) throws ExecutionException, InterruptedException {
return new Job<FeedbackType>() {
#Override
public FeedbackType doJobWithResult() throws Exception {
return FeedbackType.findByName(name);
}
}.now().get();
}
This is a private method of my Functional test and I call this method to get my object instead of directly invoking the model