spread-fences.ts:14:21 - error SC1090: conditional spreads beyond `...(c ? { field: v } : {})` (exactly one property against an empty arm — spell other shapes as optional fields) is not supported yet

  13 | const cond = true;
  14 | const s1: Shape = { ...(cond ? { x: 1, y: 2 } : { x: 3, y: 4 }) };
     |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  15 | interface YOnly {