Typed Object Path Value

typedObjectPathValue.ts

type ObjectPathValue<T, U extends readonly string[]> = U extends [
  infer FirstProp extends keyof T,
  ...infer RestProps extends readonly string[]
]
  ? ObjectPathValue<T[FirstProp], RestProps>
  : T;

function $get<T extends object, U extends readonly string[]>(
  target: T,
  path: [...U]
): ObjectPathValue<T, U> {
  for (let i = 0; i < path.length - 1; i++) target = (target as any)[path[i]];
  return (target as any)[path[path.length - 1]];
}