Merge pull request #44 from LeakIX/fix-decimal-normalize

Fix Decimal.normalize() causing silent precision loss

Author: dannywillems

CHANGELOG.md

@@ -27,6 +27,8 @@ and this project adheres to
 ### Fixed
 
 - Fix leaked file handles in tests using context managers ([b66a6f5], [#25])
+- Fix `Decimal.normalize()` stripping trailing zeros, breaking round-trip
+  serialization; add regression test ([28c76f1], [0130743], [#28])
 - Fix typo in test name: `test_l9events_form_ip4scout` ->
   `test_l9events_from_ip4scout` ([0d8736e], [#27])
 
@@ -152,6 +154,8 @@ and this project adheres to
 
 <!-- Commit links -->
 
+[0130743]: https://github.com/LeakIX/l9format-python/commit/0130743
+[28c76f1]: https://github.com/LeakIX/l9format-python/commit/28c76f1
 [b66a6f5]: https://github.com/LeakIX/l9format-python/commit/b66a6f5
 [cbea4fc]: https://github.com/LeakIX/l9format-python/commit/cbea4fc
 [3547e22]: https://github.com/LeakIX/l9format-python/commit/3547e22
@@ -221,6 +225,7 @@ and this project adheres to
 [#21]: https://github.com/LeakIX/l9format-python/issues/21
 [#22]: https://github.com/LeakIX/l9format-python/issues/22
 [#26]: https://github.com/LeakIX/l9format-python/issues/26
+[#28]: https://github.com/LeakIX/l9format-python/issues/28
 [#27]: https://github.com/LeakIX/l9format-python/issues/27
 [#33]: https://github.com/LeakIX/l9format-python/issues/33
 [#25]: https://github.com/LeakIX/l9format-python/issues/25

l9format/l9format.py

@@ -6,9 +6,7 @@
 def round_decimal(
     decimal_obj: decimal.Decimal, num_of_places: int = 6
 ) -> decimal.Decimal:
-    return decimal_obj.quantize(
-        decimal.Decimal(10) ** -num_of_places
-    ).normalize()
+    return decimal_obj.quantize(decimal.Decimal(10) ** -num_of_places)
 
 
 class Decimal(fields.Instance):

tests/test_validation.py

@@ -303,6 +303,14 @@ def test_geopoint_negative_values(self) -> None:
         assert gp.lat == -1.5
         assert gp.lon == -2.5
 
+    def test_geopoint_round_trip_preserves_value(self) -> None:
+        """Regression: normalize() used to strip trailing zeros."""
+        gp = GeoPoint.from_dict({"lat": "1.000000", "lon": "2.500000"})
+        serialized = gp.to_dict()
+        gp2 = GeoPoint.from_dict(serialized)
+        assert gp2.lat == gp.lat
+        assert gp2.lon == gp.lon
+
 
 class TestComplexNestedValidation:
     """Test validation behavior with complex nested structures."""