Fix ConversionFieldValue validator to accept explicit null attribute values

infrahub_sdk/convert_object_type.py

@@ -33,9 +33,7 @@ class ConversionFieldValue(BaseModel):  # Only one of these fields can be not No
 
     @model_validator(mode="after")
     def check_only_one_field(self) -> ConversionFieldValue:
-        fields = [self.attribute_value, self.peer_id, self.peers_ids]
-        set_fields = [f for f in fields if f is not None]
-        if len(set_fields) != 1:
+        if len(self.model_fields_set) != 1:
             raise ValueError("Exactly one of `attribute_value`, `peer_id`, or `peers_ids` must be set")
         return self
 

tests/unit/sdk/test_convert_object_type.py

@@ -0,0 +1,102 @@
+from __future__ import annotations
+
+import pytest
+from pydantic import ValidationError
+
+from infrahub_sdk.convert_object_type import ConversionFieldInput, ConversionFieldValue
+
+
+class TestConversionFieldValue:
+    def test_attribute_value_with_value(self) -> None:
+        """Test ConversionFieldValue with a normal attribute value."""
+        value = ConversionFieldValue(attribute_value="test_value")
+        assert value.attribute_value == "test_value"
+        assert value.peer_id is None
+        assert value.peers_ids is None
+
+    def test_attribute_value_with_none(self) -> None:
+        """Test ConversionFieldValue with explicit null attribute value.
+
+        This is the bug case from the issue - when UI sends {"attribute_value": null},
+        it should be accepted as a valid way to set an attribute to null.
+        """
+        value = ConversionFieldValue(attribute_value=None)
+        assert value.attribute_value is None
+        assert value.peer_id is None
+        assert value.peers_ids is None
+        assert "attribute_value" in value.model_fields_set
+
+    def test_peer_id(self) -> None:
+        """Test ConversionFieldValue with peer_id."""
+        value = ConversionFieldValue(peer_id="some-uuid")
+        assert value.attribute_value is None
+        assert value.peer_id == "some-uuid"
+        assert value.peers_ids is None
+
+    def test_peers_ids(self) -> None:
+        """Test ConversionFieldValue with peers_ids."""
+        value = ConversionFieldValue(peers_ids=["id1", "id2"])
+        assert value.attribute_value is None
+        assert value.peer_id is None
+        assert value.peers_ids == ["id1", "id2"]
+
+    def test_no_fields_set_fails(self) -> None:
+        """Test that ConversionFieldValue without any fields fails validation."""
+        with pytest.raises(ValidationError) as exc_info:
+            ConversionFieldValue()
+        assert "Exactly one of `attribute_value`, `peer_id`, or `peers_ids` must be set" in str(exc_info.value)
+
+    def test_multiple_fields_set_fails(self) -> None:
+        """Test that ConversionFieldValue with multiple fields fails validation."""
+        with pytest.raises(ValidationError) as exc_info:
+            ConversionFieldValue(attribute_value="test", peer_id="id")
+        assert "Exactly one of `attribute_value`, `peer_id`, or `peers_ids` must be set" in str(exc_info.value)
+
+
+class TestConversionFieldInput:
+    def test_source_field(self) -> None:
+        """Test ConversionFieldInput with source_field."""
+        field_input = ConversionFieldInput(source_field="name")
+        assert field_input.source_field == "name"
+        assert field_input.data is None
+        assert field_input.use_default_value is False
+
+    def test_data_with_attribute_value(self) -> None:
+        """Test ConversionFieldInput with data containing an attribute value."""
+        field_value = ConversionFieldValue(attribute_value="test_value")
+        field_input = ConversionFieldInput(data=field_value)
+        assert field_input.source_field is None
+        assert field_input.data == field_value
+        assert field_input.use_default_value is False
+
+    def test_data_with_null_attribute_value(self) -> None:
+        """Test ConversionFieldInput with data containing null attribute value.
+
+        This is the full chain from the issue - when UI sends:
+        {"city": {"data": {"attribute_value": null}}}
+        """
+        field_value = ConversionFieldValue(attribute_value=None)
+        field_input = ConversionFieldInput(data=field_value)
+        assert field_input.source_field is None
+        assert field_input.data is not None
+        assert field_input.data.attribute_value is None
+        assert field_input.use_default_value is False
+
+    def test_use_default_value(self) -> None:
+        """Test ConversionFieldInput with use_default_value."""
+        field_input = ConversionFieldInput(use_default_value=True)
+        assert field_input.source_field is None
+        assert field_input.data is None
+        assert field_input.use_default_value is True
+
+    def test_no_fields_set_fails(self) -> None:
+        """Test that ConversionFieldInput without any fields fails validation."""
+        with pytest.raises(ValidationError) as exc_info:
+            ConversionFieldInput()
+        assert "Exactly one of `source_field`, `data` or `use_default_value` must be set" in str(exc_info.value)
+
+    def test_multiple_fields_set_fails(self) -> None:
+        """Test that ConversionFieldInput with multiple fields fails validation."""
+        with pytest.raises(ValidationError) as exc_info:
+            ConversionFieldInput(source_field="name", use_default_value=True)
+        assert "Exactly one of `source_field`, `data` or `use_default_value` must be set" in str(exc_info.value)