Merge pull request #203 from khaeru/fix/empty-id

Preserve IdentifiableArtefact(id="")

doc/whatsnew.rst

@@ -3,8 +3,10 @@
 What's new?
 ***********
 
-.. Next release
-.. ============
+Next release
+============
+
+- Bugfix: in v2.19.0 (only), :py:`IdentifableArtefact(id="")` resulted in the given ID (an empty :class:`str`) being incorrectly replaced with :data:`~.common.MissingID` (:pull:`203`).
 
 v2.19.0 (2024-10-23)
 ====================

sdmx/model/common.py

@@ -146,6 +146,7 @@ def __eq__(self, other):
         return isinstance(other, self.__class__)
 
 
+#: Singleton used for :attr:`.IdentifiableArtefact.id` if none given.
 MissingID = _MissingID()
 
 
@@ -245,7 +246,8 @@ def __post_init__(self):
         # Validate URN, if any
         self._urn = URN(self.urn)
 
-        if not self.id:
+        if self.id is MissingID:
+            # Try to retrieve an item ID from the URN, if any
             self.id = self._urn.item_id or self._urn.id or MissingID
         elif self.urn and self.id not in (self._urn.item_id or self._urn.id):
             # Ensure explicit ID is consistent with URN

sdmx/tests/model/test_common.py

@@ -93,6 +93,17 @@ def test_eval_annotation(self, caplog) -> None:
 
 
 class TestIdentifiableArtefact:
+    def test_init_empty_id(self):
+        """IdentifiableArtefact can be initialized with an empty :class:`str` as ID."""
+        # No id= parameter → id attribute is MissingID
+        ia0 = IdentifiableArtefact()
+        assert common.MissingID == ia0.id
+        assert common.MissingID is ia0.id
+
+        # Empty string parameter → id attribute is empty string
+        ia1 = IdentifiableArtefact(id="")
+        assert "" == ia1.id
+
     def test_init_urn(self):
         """IdentifiableArtefact can be initialized with URN."""
         ia = IdentifiableArtefact(urn=URN)