model: fix default Edm.DateTimeOffset value (#195)

Default value was broken in several ways:
- Month 0 does not exist
- Day 0 does not exist
- Year 0 can not be handled by Python datetime

Author: rettichschnidi

CHANGELOG.md

@@ -6,7 +6,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
 - Fix Increased robustness when schema with empty properties is returned
+- Use valid default value for Edm.DateTimeOffset - Reto Schneider
 
 ## [1.8.0]
 

pyodata/v2/model.py

@@ -200,7 +200,7 @@ def _build_types():
             Types.register_type(Typ('Edm.String', '\'\'', EdmStringTypTraits()))
             Types.register_type(Typ('Edm.Time', 'time\'PT00H00M\''))
             Types.register_type(
-                Typ('Edm.DateTimeOffset', 'datetimeoffset\'0000-00-00T00:00:00Z\'', EdmDateTimeOffsetTypTraits()))
+                Typ('Edm.DateTimeOffset', 'datetimeoffset\'1753-01-01T00:00:00Z\'', EdmDateTimeOffsetTypTraits()))
 
     @staticmethod
     def register_type(typ):

tests/test_service_v2.py

@@ -2379,7 +2379,9 @@ def test_parsing_of_datetime_before_unix_time(service):
     ('/Date(981173106000+0001)/', datetime.datetime(2001, 2, 3, 4, 5, 6,
                                                     tzinfo=datetime.timezone(datetime.timedelta(minutes=1)))),
     ('/Date(981173106000-0001)/', datetime.datetime(2001, 2, 3, 4, 5, 6,
-                                                    tzinfo=datetime.timezone(-datetime.timedelta(minutes=1))))])
+                                                    tzinfo=datetime.timezone(-datetime.timedelta(minutes=1)))),
+    (None, datetime.datetime(1753, 1, 1, 0, 0, 0, tzinfo=datetime.timezone.utc)),
+])
 def test_parsing_of_datetimeoffset(service, json_input, expected):
     """Test DateTimeOffset handling."""