dumpers: fix issue with none values in model

invenio_records/dumpers/elasticsearch.py

@@ -94,6 +94,8 @@ def _serialize(value, dump_type):
         :param dump_type: Data type use for serialization (supported: str, int,
             bool, float, datetime, date, uuid).
         """
+        if value is None:
+            return value
         if dump_type in (datetime, ):
             return pytz.utc.localize(value).isoformat()
         elif dump_type in (UUID, ):
@@ -110,6 +112,8 @@ def _deserialize(value, dump_type):
         :param dump_type: Data type use for deserialization (supported: str,
             int, bool, float, datetime, date, uuid).
         """
+        if value is None:
+            return value
         if dump_type in (datetime, ):
             return arrow.get(value).datetime.replace(tzinfo=None)
         elif dump_type in (UUID, ):

tests/test_field_model.py

@@ -30,10 +30,8 @@ class Record1Metadata(db.Model, RecordMetadataBase):
         __tablename__ = 'record1_metadata'
         # __versioned__ = None
 
-        expires_at = db.Column(
-            db.DateTime(),
-            nullable=False
-        )
+        expires_at = db.Column(db.DateTime())
+
     Record1Metadata.__table__.create(db.engine)
 
     class Record1(Record, SystemFieldsMixin):
@@ -88,3 +86,10 @@ class Record1(Record, SystemFieldsMixin):
     dump = record.dumps()
     loaded_record = record.loads(dump)
     assert loaded_record.expires_at == record.expires_at
+
+    # Test dumping with None
+    record = Record1.create({})
+    dump = record.dumps()
+    print(dump)
+    loaded_record = record.loads(dump)
+    assert loaded_record.expires_at is None