fix: Preserve version tag in response column names for multi-version …

…queries When version-qualified refs (e.g. fv@v1:feat, fv@v2:feat) are used, include the version tag in full_feature_names output so multi-version queries produce distinct columns (fv@v1__feat vs fv@v2__feat). Also fix proto roundtrip test to match -1 sentinel behavior. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
feast-dev · franciscojavierarceo · Mar 26, 2026 · Mar 12, 2026 · Mar 12, 2026 · Mar 13, 2026
commit d23c4bb4b4d0170dfea7c11fe0be34096fd0a36f
@@ -543,21 +543,9 @@ def _validate_feature_refs(feature_refs: List[str], full_feature_names: bool = F
     collided_feature_refs = []
 
     if full_feature_names:
-        # Use clean names (without @vN) to detect collisions, since the response
-        # strips version tags. E.g. 'fv@v1:feat' and 'fv@v2:feat' both produce 'fv__feat'.
-        clean_refs = [
-            f"{_parse_feature_ref(ref)[0]}__{_parse_feature_ref(ref)[2]}"
-            for ref in feature_refs
+        collided_feature_refs = [
+            ref for ref, occurrences in Counter(feature_refs).items() if occurrences > 1
         ]
-        collided_clean = [
-            name for name, count in Counter(clean_refs).items() if count > 1
-        ]
-        if collided_clean:
-            collided_feature_refs = [
-                ref
-                for ref, clean in zip(feature_refs, clean_refs)
-                if clean in collided_clean
-            ]
     else:
         feature_names = [_parse_feature_ref(ref)[2] for ref in feature_refs]
         collided_feature_names = [
@@ -1122,10 +1110,13 @@ def _populate_response_from_feature_data(
         output_len: The number of result rows in `online_features_response`.
     """
     # Add the feature names to the response.
-    # Use clean name without version tag for response feature names
+    # Use name_to_use() which includes version tag (e.g. "fv@v2") when a
+    # version-qualified ref was used, so multi-version queries produce
+    # distinct column names like "fv@v1__feat" and "fv@v2__feat".
+    table_name = table.projection.name_to_use()
     clean_table_name = table.projection.name_alias or table.projection.name
     requested_feature_refs = [
-        f"{clean_table_name}__{feature_name}" if full_feature_names else feature_name
+        f"{table_name}__{feature_name}" if full_feature_names else feature_name
         for feature_name in requested_features
     ]
     online_features_response.metadata.feature_names.val.extend(requested_feature_refs)
@@ -1408,12 +1399,18 @@ def _get_online_request_context(
         requested_on_demand_feature_views,
     )
 
-    # Build expected result names using clean FV names (without @vN syntax)
+    # Build expected result names, including version tag when present so
+    # multi-version queries (e.g. fv@v1:feat, fv@v2:feat) match the response.
     requested_result_row_names = set()
     for feat_ref in _feature_refs:
-        fv_name, _, feature_name = _parse_feature_ref(feat_ref)
+        fv_name, version_num, feature_name = _parse_feature_ref(feat_ref)
         if full_feature_names:
-            requested_result_row_names.add(f"{fv_name}__{feature_name}")
+            if version_num is not None:
+                requested_result_row_names.add(
+                    f"{fv_name}@v{version_num}__{feature_name}"
+                )
+            else:
+                requested_result_row_names.add(f"{fv_name}__{feature_name}")
         else:
             requested_result_row_names.add(feature_name)
 

@@ -176,9 +176,8 @@ def test_feature_view_proto_roundtrip_v0(self):
         assert fv2.current_version_number == 0
 
     def test_feature_view_proto_roundtrip_latest_zero(self):
-        """version='latest' with current_version_number=None becomes 0 after
-        proto roundtrip because proto3 cannot distinguish unset int32 from 0.
-        This is acceptable — 0 is the correct initial version number."""
+        """version='latest' with current_version_number=None is preserved as
+        None through proto roundtrip using a -1 sentinel in the proto."""
         from datetime import timedelta
 
         from feast.entity import Entity
@@ -196,8 +195,8 @@ def test_feature_view_proto_roundtrip_latest_zero(self):
         proto = fv.to_proto()
         fv2 = FeatureView.from_proto(proto)
         assert fv2.version == "latest"
-        # proto3 int32 default is 0; with version="latest" set, we preserve 0
-        assert fv2.current_version_number == 0
+        # -1 sentinel in proto correctly preserves None through roundtrip
+        assert fv2.current_version_number is None
 
     def test_feature_view_equality_with_version(self):
         from datetime import timedelta