webstrand

/******************************************************************************
 * Implementation of `Nonempty` validator which checks that the provided type
 * has at least one defined property, excluding `{}`.
 ******************************************************************************/
type Nonempty<T extends { [key: string]: any }> = { [P in keyof T]: T }[keyof T];
declare function wantsNonempty<T extends { [key: string]: any }>(x: Nonempty<T>): true;

wantsNonempty({ x: 1 });
wantsNonempty({}); // error expected