model: set UTC timezone to DateTimes read rom JSON too

I came a cross this difference during testing of SAP#95

I decided to set tzinfo of JSON DateTimes to simplify my tests and it
also make sense to me to have the values configured the same way.

Author: filak-sap

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 - support for Edm.Float - Jakub Filak
 
+### Changed
+- both Literal and JSON DateTimes has Timezone set to UTC - Jakub Filak
+
 ### Fixed
 - removed superfluous debug print when parsing FunctionImports from metadata - Jakub Filak
 

pyodata/v2/model.py

@@ -426,7 +426,7 @@ def from_literal(self, value):
                 except ValueError:
                     raise PyODataModelError('Cannot decode datetime from value {}.'.format(value))
 
-        return value
+        return value.replace(tzinfo=datetime.timezone.utc)
 
 
 class EdmStringTypTraits(TypTraits):

tests/test_model_v2.py

@@ -468,19 +468,22 @@ def test_traits_datetime():
     assert testdate.minute == 33
     assert testdate.second == 6
     assert testdate.microsecond == 654321
+    assert testdate.tzinfo == timezone.utc
 
     # parsing without miliseconds
     testdate = typ.traits.from_literal("datetime'1976-11-23T03:33:06'")
     assert testdate.year == 1976
     assert testdate.second == 6
     assert testdate.microsecond == 0
+    assert testdate.tzinfo == timezone.utc
 
     # parsing without seconds and miliseconds
     testdate = typ.traits.from_literal("datetime'1976-11-23T03:33'")
     assert testdate.year == 1976
     assert testdate.minute == 33
     assert testdate.second == 0
     assert testdate.microsecond == 0
+    assert testdate.tzinfo == timezone.utc
 
     # parsing invalid value
     with pytest.raises(PyODataModelError) as e_info:
@@ -502,19 +505,22 @@ def test_traits_datetime():
     assert testdate.minute == 33
     assert testdate.second == 6
     assert testdate.microsecond == 10000
+    assert testdate.tzinfo == timezone.utc
 
     # parsing without miliseconds
     testdate = typ.traits.from_json("/Date(217567986000)/")
     assert testdate.year == 1976
     assert testdate.second == 6
     assert testdate.microsecond == 0
+    assert testdate.tzinfo == timezone.utc
 
     # parsing without seconds and miliseconds
     testdate = typ.traits.from_json("/Date(217567980000)/")
     assert testdate.year == 1976
     assert testdate.minute == 33
     assert testdate.second == 0
     assert testdate.microsecond == 0
+    assert testdate.tzinfo == timezone.utc
 
     # parsing the lowest value
     with pytest.raises(OverflowError):
@@ -528,6 +534,7 @@ def test_traits_datetime():
     assert testdate.minute == 0
     assert testdate.second == 0
     assert testdate.microsecond == 0
+    assert testdate.tzinfo == timezone.utc
 
     # parsing the highest value
     with pytest.raises(OverflowError):
@@ -541,6 +548,7 @@ def test_traits_datetime():
     assert testdate.minute == 59
     assert testdate.second == 59
     assert testdate.microsecond == 999000
+    assert testdate.tzinfo == timezone.utc
 
     # parsing invalid value
     with pytest.raises(PyODataModelError) as e_info: