I'm trying to put together a simple environment where I can get Spring, Maven, JPA, Google App Engine and DAO unit testing working happily all together.

The goal is to be able to run a simple DAO unit test creating an entity and then load it again with a simple find to check it's been created properly - all of this from my maven build.

My dao is making use of the JPA entity manager (query(), persist(), etc.)

I've got it working no problem with hsqldb and a datasource, etc. but I'm struggling to get it working with appengine.

My questions are:

1) I'm using an entity manager, injecting my persistence unit as followed. Is it OK? Is there any need for a datasource or something special? I thought not but correct me if I'm wrong.

applicationContext.xml

    <bean id='entityManagerFactory' class='org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean'>
     <property name="persistenceUnitName" value="transactions-optional" />
    </bean>

Persistence.xml

   <persistence-unit name="transactions-optional">
    <provider>org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider</provider>
    <properties>
        <property name="datanucleus.NontransactionalRead" value="true"/>
        <property name="datanucleus.NontransactionalWrite" value="true"/>
        <property name="datanucleus.ConnectionURL" value="appengine"/>
    </properties>
   </persistence-unit>

2) what are the dependencies I need to add to my pom file to be able to run the unit test making use of the entityManager? What about versions ? I found loads of things about appengine-api-labs/stubs/testing but none them got it working i.e. I'm getting jdo dependency missing while I'm using JPA... I also get loads of conflicts when I try to add some jars (datanucleus and stuff).

So far I'm trying appengine-api-1.0-sdk v1.7.0 -> ASM-all v3.3 -> datanucleus core/api-jpa/enhancer v3.1.0 -> datanucleus-appengine v2.0.1.1 and all the gae testing jars v1.7.0

3) Is there anything I need to add to my surefire plugin (test runner) to make sure it picks up all the dependencies? I'm getting an exhausting ClassNotFound on DatastorePersistenceProvider while it is in my classpath (I checked the jars and the mvn dependency:tree)

I had a look at this but it doesn't seem to be working at all: http://www.vertigrated.com/blog/2011/02/working-maven-3-google-app-engine-plugin-with-gwt-support/

4) Do I need to use any sot of localhelper to test my DAOs? Ideally I'd want to test my dao layer "as is" with the entity manager... what's your opinion ? Has anyone managed to run a unit test using JPA on google app engine ?

5) Do I need to set up any sort of gae.home somewhere in my pom file? Would anyone make use of it (a plugin or something) ?

6) Is the gwt-maven plugin any helpful if I don't use gwt - I'm writing a simple webservice making use of appengine, not a GWT app...

Any help would be much appreciated as I've been struggling for 2 days now...

Cheers, V.