/** * Takes as type argument an Api interface and return * an union type constituted of all the properties names * whose values are functions. * * Example: * * interface Api { * getFoo(): number; * getBar(): string; * p: object; * } * * MethodNames<Api> is "getFoo" | "getBar" * */ export type MethodNames<Api extends {}> = keyof { [K in Exclude< keyof Api, ({ [P in keyof Api]: Api[P] extends Function ? never : P })[keyof Api]> ]: Api[K]};