Question

I’m having a strange problem with unit test in grails, when I try to save a mocked object it throw a NullPointerException

 java.lang.NullPointerException
at org.grails.datastore.mapping.engine.NativeEntryEntityPersister.persistEntity(NativeEntryEntityPersister.java:798)
at org.grails.datastore.mapping.engine.EntityPersister.persist(EntityPersister.java:130)
at org.grails.datastore.mapping.core.AbstractSession.persist(AbstractSession.java:477)
at org.grails.datastore.gorm.GormInstanceApi.doSave(GormInstanceApi.groovy:166)
at org.grails.datastore.gorm.GormInstanceApi$_save_closure4.doCall(GormInstanceApi.groovy:143)
at org.grails.datastore.mapping.core.DatastoreUtils.execute(DatastoreUtils.java:301)
at org.grails.datastore.gorm.AbstractDatastoreApi.execute(AbstractDatastoreApi.groovy:34)
at org.grails.datastore.gorm.GormInstanceApi.save(GormInstanceApi.groovy:142)
at it.rascio.ConverterServiceTests.testConvert(ConverterServiceTests.groovy:64)

what I have the test like:

@TestFor(ConverterService)
@TestMixin(GrailsUnitTestMixin)
@Mock([MyObj1, MyObj2, LittleObject])
class ConverterServiceTests{
   def littleObject;
   void setUp(){
         littleObject = new LittleObject(prop1: 'hello', prop2: 'world')
   }

   void testConvert(){
    MyObj1 obj = new MyObj1()
    obj.prop = 'my property'
    obj.littleObject = littleObject
    obj = obj.save(flush:true, failOnError: true)

    MyObj2 b = new MyObj2()
    b.obj1Id = obj.id;

    assert service.convert(b) == null;


}

The exception is thrown when I call the .save method.
I’ve seen that if I remove the littleObject it works.
Can someone have an idea of what is this exception?

Answer 1

If your class MyObj1 contains some embedded properties of other types or has any other cascade saves you should add these classes to @Mock annotation list.