Merge pull request mozilla#491 from bendk/mozillagh-490

Fixed timestamp conversion during DST

CHANGELOG.md

@@ -18,6 +18,7 @@
 ### What's Changed
 
 - Both python and ruby backends now handle U16 correctly.
+- Python timestamps will now be in UTC and timezone-aware rather than naive.
 
 ## v0.12.0 (2021-06-14)
 

fixtures/uniffi-fixture-time/tests/bindings/test_chronological.py

@@ -3,39 +3,40 @@
 import sys
 
 # Test passing timestamp and duration while returning timestamp
-assert add(datetime.fromtimestamp(100.000001), timedelta(seconds=1, microseconds=1)).timestamp() == 101.000002
+assert add(datetime.fromtimestamp(100.000001, timezone.utc), timedelta(seconds=1, microseconds=1)).timestamp() == 101.000002
 
 # Test passing timestamp while returning duration
-assert diff(datetime.fromtimestamp(101.000002), datetime.fromtimestamp(100.000001)) == timedelta(seconds=1, microseconds=1)
+assert diff(datetime.fromtimestamp(101.000002, timezone.utc), datetime.fromtimestamp(100.000001, timezone.utc)) == timedelta(seconds=1, microseconds=1)
 
 # Test pre-epoch timestamps
-assert add(datetime.fromisoformat('1955-11-05T00:06:00.283001'), timedelta(seconds=1, microseconds=1)) == datetime.fromisoformat('1955-11-05T00:06:01.283002')
+assert add(datetime.fromisoformat('1955-11-05T00:06:00.283001+00:00'), timedelta(seconds=1, microseconds=1)) == datetime.fromisoformat('1955-11-05T00:06:01.283002+00:00')
 
 # Test exceptions are propagated
 try:
-    diff(datetime.fromtimestamp(100), datetime.fromtimestamp(101))
+    diff(datetime.fromtimestamp(100, timezone.utc), datetime.fromtimestamp(101, timezone.utc))
     assert(not("Should have thrown a TimeDiffError exception!"))
 except ChronologicalError.TimeDiffError:
     # It's okay!
     pass
 
 # Test near max timestamp bound, no microseconds due to python floating point precision issues
-assert add(datetime(MAXYEAR, 12, 31, 23, 59, 59, 0), timedelta(seconds=0)) == datetime(MAXYEAR, 12, 31, 23, 59, 59, 0)
+assert add(datetime(MAXYEAR, 12, 31, 23, 59, 59, 0, tzinfo=timezone.utc), timedelta(seconds=0)) == datetime(MAXYEAR, 12, 31, 23, 59, 59, 0, tzinfo=timezone.utc)
 
 # Test overflow at max timestamp bound
 try:
-    add(datetime(MAXYEAR, 12, 31, 23, 59, 59, 0), timedelta(seconds=1))
+    add(datetime(MAXYEAR, 12, 31, 23, 59, 59, 0, tzinfo=timezone.utc), timedelta(seconds=1))
     assert(not("Should have thrown a ValueError exception!"))
 except OverflowError:
     # It's okay!
     pass
 
 # Test that rust timestamps behave like kotlin timestamps
-pythonBefore = datetime.now()
+pythonBefore = datetime.now(timezone.utc)
 rustNow = now()
-pythonAfter = datetime.now()
+pythonAfter = datetime.now(timezone.utc)
 
 assert pythonBefore <= rustNow <= pythonAfter
 
-# Test that uniffi returns naive datetime
-assert now().tzinfo is None
+# Test that uniffi returns UTC times
+assert now().tzinfo is timezone.utc
+assert abs(datetime.now(timezone.utc) - now()) <= timedelta(seconds=1)

uniffi_bindgen/src/bindings/python/templates/RustBufferBuilder.py

@@ -109,12 +109,12 @@ def writeString(self, v):
     {% when Type::Timestamp -%}
 
     def write{{ canonical_type_name }}(self, v):
-        if v >= datetime.datetime.fromtimestamp(0):
+        if v >= datetime.datetime.fromtimestamp(0, datetime.timezone.utc):
             sign = 1
-            delta = v - datetime.datetime.fromtimestamp(0)
+            delta = v - datetime.datetime.fromtimestamp(0, datetime.timezone.utc)
         else:
             sign = -1
-            delta = datetime.datetime.fromtimestamp(0) - v
+            delta = datetime.datetime.fromtimestamp(0, datetime.timezone.utc) - v
 
         seconds = delta.seconds + delta.days * 24 * 3600
         nanoseconds = delta.microseconds * 1000

uniffi_bindgen/src/bindings/python/templates/RustBufferStream.py

@@ -113,10 +113,13 @@ def readString(self):
     def read{{ canonical_type_name }}(self):
         seconds = self._unpack_from(8, ">q")
         microseconds = self._unpack_from(4, ">I") / 1000
+        # Use fromtimestamp(0) then add the seconds using a timedelta.  This
+        # ensures that we get OverflowError rather than ValueError when
+        # seconds is too large.
         if seconds >= 0:
-            return datetime.datetime.fromtimestamp(0, tz=None) + datetime.timedelta(seconds=seconds, microseconds=microseconds)
+            return datetime.datetime.fromtimestamp(0, tz=datetime.timezone.utc) + datetime.timedelta(seconds=seconds, microseconds=microseconds)
         else:
-            return datetime.datetime.fromtimestamp(0, tz=None) - datetime.timedelta(seconds=-seconds, microseconds=microseconds)
+            return datetime.datetime.fromtimestamp(0, tz=datetime.timezone.utc) - datetime.timedelta(seconds=-seconds, microseconds=microseconds)
 
     {% when Type::Duration -%}
     # The Duration type.