Create schema_utils.py

schema_utils.py

@@ -0,0 +1,23 @@
+# schema_utils.py
+from typing import Dict, Set
+from schema_map import schema
+
+def fieldset_for(collection: str) -> Set[str]:
+    col = schema.get(collection, {})
+    fields = {k for k in col.keys() if not k.startswith("$")}
+    # expand nested alias target names too
+    aliases = col.get("$aliases", {}) or {}
+    fields |= set(aliases.values())
+    return fields
+
+def alias_map_for(collection: str) -> Dict[str, str]:
+    col = schema.get(collection, {})
+    return col.get("$aliases", {}) or {}
+
+def resolve_field(collection: str, field: str) -> str:
+    """Return the canonical field name (apply alias if present)."""
+    aliases = alias_map_for(collection)
+    return aliases.get(field, field)
+
+def has_field(collection: str, field: str) -> bool:
+    return resolve_field(collection, field) in fieldset_for(collection)