Write a test for merging tasks, fix TaskMixin problem because of null…

…able foreign key (parent)

pepys_import/core/store/common_db.py

@@ -226,7 +226,7 @@ def get_sensor(
 class TaskMixin:
     @declared_attr
     def parent(self):
-        return relationship("Task", lazy="joined", join_depth=1, innerjoin=True, uselist=False)
+        return relationship("Task")
 
     @declared_attr
     def parent_name(self):

pepys_import/core/store/data_store.py

@@ -1849,7 +1849,7 @@ def merge_generic(self, table_name, id_list, master_id) -> bool:
 
         if table_name == constants.PLATFORM:
             self.merge_platforms(id_list, master_id, change_id)
-        if table_name in [constants.SENSOR, constants.DATAFILE]:
+        elif table_name in [constants.SENSOR, constants.DATAFILE]:
             self.merge_measurements(table_name, id_list, master_id, change_id)
         elif table_name in reference_table_names + [constants.TAG, constants.TASK]:
             self.merge_objects(table_name, id_list, master_id, change_id)

tests/test_data_store_merge_operations.py

@@ -1,4 +1,4 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 from unittest import TestCase
 from uuid import UUID
 
@@ -1383,6 +1383,73 @@ def test_merge_generic_privacies(self):
                 .scalar()
             )
 
+    def test_merge_generic_tasks(self):
+        Task = self.store.db_classes.Task
+        Geometry1 = self.store.db_classes.Geometry1
+        GeometrySubType = self.store.db_classes.GeometrySubType
+        Participant = self.store.db_classes.Participant
+        with self.store.session_scope():
+            start = datetime.now()
+            end = start + timedelta(seconds=100)
+            old_task = Task(
+                name="TEST TASK",
+                start=start,
+                end=end,
+                privacy_id=self.privacy_id,
+            )
+            geo_type = self.store.db_classes.GeometryType(name="Test GeoType")
+            self.store.session.add(old_task)
+            self.store.session.add(geo_type)
+            self.store.session.flush()
+            geo_sub_type = GeometrySubType(name="Test GeoSubType", parent=geo_type.geo_type_id)
+            self.store.session.add(geo_sub_type)
+            self.store.session.flush()
+            geometry = Geometry1(
+                subject_platform_id=self.platform_2.platform_id,
+                _geometry=WKTElement("POINT(123456 123456)", srid=4326),
+                geo_type_id=geo_type.geo_type_id,
+                geo_sub_type_id=geo_sub_type.geo_sub_type_id,
+                source_id=self.file.datafile_id,
+                task_id=old_task.task_id,
+            )
+            participant = Participant(
+                platform_id=self.platform_2.platform_id,
+                task_id=old_task.task_id,
+                privacy_id=self.privacy_id,
+            )
+            self.store.session.add(geometry)
+            self.store.session.add(participant)
+            self.store.session.flush()
+
+            new_task = Task(
+                name="NEW TASK",
+                start=start,
+                end=end,
+                privacy_id=self.privacy_id,
+            )
+            self.store.session.add(new_task)
+            self.store.session.commit()
+
+            # Assert that target task doesn't have any dependent objects
+            dependent_objs = list(dependent_objects(new_task))
+            assert len(dependent_objs) == 0
+            source_dependent_objs = list(dependent_objects(old_task))
+            assert len(source_dependent_objs) == 2  # 1 Geometry, 1 Participant
+
+            # Merge old_task to new_task
+            assert self.store.merge_generic(constants.TASK, [old_task.task_id], new_task.task_id)
+
+            # Assert that target task has all dependent objects
+            dependent_objs = list(dependent_objects(new_task))
+            assert len(dependent_objs) == 2
+            source_dependent_objs = list(dependent_objects(old_task))
+            assert len(source_dependent_objs) == 0
+
+            # Assert that merged task deleted
+            assert (
+                not self.store.session.query(Task).filter(Task.task_id == old_task.task_id).scalar()
+            )
+
     def test_merge_generic_wrong_table_name(self):
         with self.store.session_scope():
             assert (