fix: nondefault model version

google/cloud/aiplatform/models.py

@@ -5155,6 +5155,14 @@ def resource_name(self) -> str:
         self._assert_gca_resource_is_available()
         return ModelRegistry._parse_versioned_name(self._gca_resource.name)[0]
 
+    def _sync_gca_resource(self) -> None:
+        """Sync GAPIC service representation of client class resource.
+        Uses versioned resource name so the non-default version is not lost.
+        """
+        self._gca_resource = self._get_gca_resource(
+            resource_name=self.versioned_resource_name
+        )
+
     @property
     def name(self) -> str:
         """Name of this resource."""

tests/unit/aiplatform/test_models.py

@@ -4701,6 +4701,42 @@ def test_init_with_version_arg(self, get_model_with_version):
         # The Model yielded from upload SHOULD have a version in the versioned resource name
         assert model.versioned_resource_name.endswith(f"@{_TEST_VERSION_ID}")
 
+    def test_sync_gca_resource_uses_versioned_name(self, get_model_with_version):
+        # Regression test for https://github.com/googleapis/python-aiplatform/issues/2619
+        # _sync_gca_resource must use versioned_resource_name so the non-default
+        # version is not silently replaced by the default version.
+        model = models.Model(model_name=_TEST_MODEL_NAME, version=_TEST_VERSION_ID)
+        get_model_with_version.reset_mock()
+
+        model._sync_gca_resource()
+
+        versioned_name = models.ModelRegistry._get_versioned_name(
+            _TEST_MODEL_PARENT, _TEST_VERSION_ID
+        )
+        get_model_with_version.assert_called_once_with(
+            name=versioned_name, retry=base._DEFAULT_RETRY
+        )
+
+    def test_update_preserves_version(
+        self, update_model_mock, get_model_with_version
+    ):
+        # Regression test for https://github.com/googleapis/python-aiplatform/issues/2619
+        # Model.update() calls _sync_gca_resource(); verify it fetches the versioned name.
+        model = models.Model(model_name=_TEST_MODEL_NAME, version=_TEST_VERSION_ID)
+        get_model_with_version.reset_mock()
+
+        model.update(display_name=_TEST_MODEL_NAME)
+
+        versioned_name = models.ModelRegistry._get_versioned_name(
+            _TEST_MODEL_PARENT, _TEST_VERSION_ID
+        )
+        get_model_with_version.assert_called_once_with(
+            name=versioned_name, retry=base._DEFAULT_RETRY
+        )
+        # Version must still be intact after update
+        assert model.version_id == _TEST_VERSION_ID
+        assert model.versioned_resource_name.endswith(f"@{_TEST_VERSION_ID}")
+
     @pytest.mark.parametrize(
         "parent,location,project",
         [