Store timezone-aware datetimes in empty fields (#1943)

* Store timezone-aware datetimes in empty fields

* changelog

Author: davisagli

news/+tz.bugfix

@@ -0,0 +1 @@
+When deserializing datetimes into an empty field, store them as timezone-aware datetimes. @davisagli

src/plone/restapi/deserializer/dxfields.py

@@ -123,13 +123,18 @@ def __call__(self, value):
             # Otherwise let's check what is currently stored.
             dm = queryMultiAdapter((self.context, self.field), IDataManager)
             current = dm.get()
-            if current is not None and current.tzinfo is not None:
-                # Timezone-aware. Convert to the same timezone.
-                tz = timezone(current.tzinfo.zone)
-                value = tz.normalize(dt.astimezone(tz))
+            if current is not None:
+                # There's an existing value. Let's match it.
+                if current.tzinfo is not None:
+                    # Timezone-aware. Convert to the same timezone.
+                    tz = timezone(current.tzinfo.zone)
+                    value = tz.normalize(dt.astimezone(tz))
+                else:
+                    # Timezone-naive. Convert to UTC and remove the tzinfo.
+                    value = utc.normalize(dt.astimezone(utc)).replace(tzinfo=None)
             else:
-                # Timezone-naive. Convert to UTC and remove the tzinfo.
-                value = utc.normalize(dt.astimezone(utc)).replace(tzinfo=None)
+                # No current value. Store as timezone-aware.
+                value = dt
 
         self.field.validate(value)
         return value

src/plone/restapi/tests/dxtypes.py

@@ -259,7 +259,9 @@ class IDXTestDocumentSchema(model.Schema):
     test_constraint_field = schema.TextLine(
         required=False, constraint=lambda x: "00" in x
     )
-    test_datetime_min_field = schema.Datetime(required=False, min=datetime(2000, 1, 1))
+    test_datetime_min_field = schema.Datetime(
+        required=False, min=timezone("UTC").localize(datetime(2000, 1, 1))
+    )
     test_time_min_field = schema.Time(required=False, min=time(1))
     test_timedelta_min_field = schema.Timedelta(required=False, min=timedelta(100))
     test_list_value_type_field = schema.List(required=False, value_type=schema.Int())

src/plone/restapi/tests/test_dxfield_deserializer.py

@@ -114,48 +114,54 @@ def test_date_deserialization_returns_date(self):
         self.assertTrue(isinstance(value, date))
         self.assertEqual(date(2015, 12, 20), value)
 
-    def test_datetime_deserialization_returns_datetime(self):
-        value = self.deserialize("test_datetime_field", "2015-12-20T10:39:54.361Z")
-        self.assertTrue(isinstance(value, datetime), "Not a <datetime>")
-        self.assertEqual(datetime(2015, 12, 20, 10, 39, 54, 361000), value)
-
-    def test_datetime_deserialization_handles_timezone(self):
+    def test_datetime_deserialization_defaults_to_timezone_from_request(self):
+        self.portal.doc1.test_datetime_field = None
         value = self.deserialize("test_datetime_field", "2015-12-20T10:39:54.361+01")
-        self.assertEqual(datetime(2015, 12, 20, 9, 39, 54, 361000), value)
-
-    def test_datetime_deserialization_with_tznaive_stored(self):
-        self.portal.doc1.test_datetime_field = datetime.now()
-        value = self.deserialize("test_datetime_field", "2015-12-20T10:39:54.361")
-        self.assertEqual(datetime(2015, 12, 20, 10, 39, 54, 361000), value)
-
-    def test_datetime_with_tz_deserialization_keeps_timezone(self):
-        value = self.deserialize("test_datetime_tz_field", "2015-12-20T10:39:54.361+01")
         self.assertEqual(
             timezone("Europe/Zurich").localize(
                 datetime(2015, 12, 20, 10, 39, 54, 361000)
             ),
             value,
         )
 
-    def test_datetime_with_tz_deserialization_converts_timezone(self):
-        value = self.deserialize("test_datetime_tz_field", "2015-12-20T10:39:54.361-04")
+    def test_datetime_deserialization_defaults_to_utc(self):
+        self.portal.doc1.test_datetime_field = None
+        value = self.deserialize("test_datetime_field", "2015-12-20T10:39:54.361")
+        self.assertEqual(
+            datetime(2015, 12, 20, 10, 39, 54, 361000, timezone("UTC")), value
+        )
+
+    def test_datetime_deserialization_converts_to_existing_timezone(self):
+        self.portal.doc1.test_datetime_field = timezone("Europe/Zurich").localize(
+            datetime.now()
+        )
+        value = self.deserialize("test_datetime_tz_field", "2015-12-20T10:39:54.361+01")
         self.assertEqual(
             timezone("Europe/Zurich").localize(
-                datetime(2015, 12, 20, 15, 39, 54, 361000)
+                datetime(2015, 12, 20, 10, 39, 54, 361000)
             ),
             value,
         )
 
-    def test_datetime_with_tz_deserialization_adds_timezone(self):
-        value = self.deserialize("test_datetime_tz_field", "2015-12-20T10:39:54.361")
+    def test_datetime_deserialization_adds_existing_timezone(self):
+        self.portal.doc1.test_datetime_field = timezone("Europe/Zurich").localize(
+            datetime.now()
+        )
+        value = self.deserialize("test_datetime_tz_field", "2015-12-20T9:39:54.361")
         self.assertEqual(
             timezone("Europe/Zurich").localize(
-                datetime(2015, 12, 20, 11, 39, 54, 361000)
+                datetime(2015, 12, 20, 10, 39, 54, 361000)
             ),
             value,
         )
 
+    def test_datetime_deserialization_converts_to_stored_tznaive(self):
+        self.portal.doc1.test_datetime_field = datetime.now()
+        value = self.deserialize("test_datetime_field", "2015-12-20T10:39:54.361Z")
+        self.assertEqual(datetime(2015, 12, 20, 10, 39, 54, 361000), value)
+
     def test_datetime_with_tz_deserialization_handles_dst(self):
+        self.portal.doc1.test_datetime_field = None
         value = self.deserialize("test_datetime_tz_field", "2015-05-20T10:39:54.361+02")
         self.assertEqual(
             timezone("Europe/Zurich").localize(