assert

function Flags.assert(flag: unknown): asserts flag is Flag

Asserts that a value is a valid Flag (integer between 0 and 30), throwing an error if not.

Example

import { Flags } from "@monstermann/flags";

Flags.assert(0); // ok
Flags.assert(15); // ok
Flags.assert(30); // ok
Flags.assert(31); // throws Error: flag must be >= 0 and <= 30
Flags.assert(-1); // throws Error: flag must be >= 0 and <= 30
Flags.assert(1.5); // throws Error: flag must be an integer
Flags.assert("0"); // throws Error: flag must be an integer