Avoid silent integer downcast in TimeDelta.deserialize

marshmallow-code · Dec 10, 2024 · 1dcc544 · 1dcc544
1 parent 6654eaf
commit 1dcc544
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Showing 2 changed files with 17 additions and 10 deletions.
diff --git a/src/marshmallow/fields.py b/src/marshmallow/fields.py
@@ -1526,7 +1526,7 @@ def _serialize(self, value, attr, obj, **kwargs):
 
     def _deserialize(self, value, attr, data, **kwargs):
         try:
-            value = self.serialization_type(value)
+            value = float(value)
         except (TypeError, ValueError) as error:
             raise self.make_error("invalid") from error
 

diff --git a/tests/test_deserialization.py b/tests/test_deserialization.py
@@ -709,6 +709,13 @@ def test_timedelta_field_deserialization(self):
         assert result.seconds == 42
         assert result.microseconds == 0
 
+        field = fields.TimeDelta()
+        result = field.deserialize("42.9")
+        assert isinstance(result, dt.timedelta)
+        assert result.days == 0
+        assert result.seconds == 42
+        assert result.microseconds == 900000
+
         field = fields.TimeDelta(fields.TimeDelta.SECONDS)
         result = field.deserialize(100000)
         assert result.days == 1
@@ -741,7 +748,7 @@ def test_timedelta_field_deserialization(self):
         assert isinstance(result, dt.timedelta)
         assert result.days == 0
         assert result.seconds == 12
-        assert result.microseconds == 0
+        assert result.microseconds == 900000
 
         field = fields.TimeDelta(fields.TimeDelta.WEEKS)
         result = field.deserialize(1)
@@ -772,7 +779,7 @@ def test_timedelta_field_deserialization(self):
         assert result.microseconds == 456000
 
         total_microseconds_value = 322.0
-        field = fields.TimeDelta(fields.TimeDelta.MICROSECONDS, float)
+        field = fields.TimeDelta(fields.TimeDelta.MICROSECONDS)
         result = field.deserialize(total_microseconds_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(microseconds=1).total_seconds()
@@ -781,7 +788,7 @@ def test_timedelta_field_deserialization(self):
         )
 
         total_microseconds_value = 322.12345
-        field = fields.TimeDelta(fields.TimeDelta.MICROSECONDS, float)
+        field = fields.TimeDelta(fields.TimeDelta.MICROSECONDS)
         result = field.deserialize(total_microseconds_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(microseconds=1).total_seconds()
@@ -790,7 +797,7 @@ def test_timedelta_field_deserialization(self):
         )
 
         total_milliseconds_value = 322.223
-        field = fields.TimeDelta(fields.TimeDelta.MILLISECONDS, float)
+        field = fields.TimeDelta(fields.TimeDelta.MILLISECONDS)
         result = field.deserialize(total_milliseconds_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(milliseconds=1).total_seconds()
@@ -799,34 +806,34 @@ def test_timedelta_field_deserialization(self):
         )
 
         total_seconds_value = 322.223
-        field = fields.TimeDelta(fields.TimeDelta.SECONDS, float)
+        field = fields.TimeDelta(fields.TimeDelta.SECONDS)
         result = field.deserialize(total_seconds_value)
         assert isinstance(result, dt.timedelta)
         assert math.isclose(result.total_seconds(), total_seconds_value)
 
         total_minutes_value = 322.223
-        field = fields.TimeDelta(fields.TimeDelta.MINUTES, float)
+        field = fields.TimeDelta(fields.TimeDelta.MINUTES)
         result = field.deserialize(total_minutes_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(minutes=1).total_seconds()
         assert math.isclose(result.total_seconds() / unit_value, total_minutes_value)
 
         total_hours_value = 322.223
-        field = fields.TimeDelta(fields.TimeDelta.HOURS, float)
+        field = fields.TimeDelta(fields.TimeDelta.HOURS)
         result = field.deserialize(total_hours_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(hours=1).total_seconds()
         assert math.isclose(result.total_seconds() / unit_value, total_hours_value)
 
         total_days_value = 322.223
-        field = fields.TimeDelta(fields.TimeDelta.DAYS, float)
+        field = fields.TimeDelta(fields.TimeDelta.DAYS)
         result = field.deserialize(total_days_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(days=1).total_seconds()
         assert math.isclose(result.total_seconds() / unit_value, total_days_value)
 
         total_weeks_value = 322.223
-        field = fields.TimeDelta(fields.TimeDelta.WEEKS, float)
+        field = fields.TimeDelta(fields.TimeDelta.WEEKS)
         result = field.deserialize(total_weeks_value)
         assert isinstance(result, dt.timedelta)
         unit_value = dt.timedelta(weeks=1).total_seconds()