WIP checkpoint: US-1: Asset Import Pipeline — glTF upload endpoint with metadata extraction

backend/app/services/gltf.py

@@ -19,6 +19,10 @@ _GLB_MAGIC_INT = 0x46546C67  # b"glTF" interpreted as little-endian uint32
 _GLB_JSON_CHUNK_TYPE = 0x4E4F534A  # "JSON"
 _GLB_BIN_CHUNK_TYPE = 0x004E4942  # "BIN\0"
 
+# Whitespace allowed around a GLB JSON chunk. The spec pads with spaces (0x20),
+# but be lenient with null bytes and other whitespace that real exporters emit.
+_JSON_CHUNK_TRIM = b" \t\r\n\x00"
+
 
 def looks_like_gltf(content: bytes, filename: Optional[str] = None) -> bool:
     """Return True when the bytes or filename indicate a glTF/GLB asset."""
@@ -65,7 +69,7 @@ def _parse_glb(content: bytes) -> dict[str, Any]:
         chunk_data = content[offset:chunk_end]
         if chunk_type == _GLB_JSON_CHUNK_TYPE:
             try:
-                json_chunk = json.loads(chunk_data.decode("utf-8"))
+                json_chunk = json.loads(chunk_data.strip(_JSON_CHUNK_TRIM).decode("utf-8"))
             except (ValueError, UnicodeDecodeError) as exc:
                 raise ValueError(f"invalid GLB JSON chunk: {exc}") from exc