retired-engine-1123-any-conditional-spread.ts:21:21 - 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

  20 | function multi(on: boolean): any {
  21 |   return { base: 1, ...(on ? { x: "X", y: "Y" } : {}) };
     |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  22 | }