real modulo operation in typescript

mod.ts

/**
 * Real modulo operation that works correctly with negative numbers.
 *
 * JavaScript's `%` operator returns the remainder of a division operation,
 * which may be negative. This function corrects that by adding the base before
 * taking the remainder.
 */
export function mod(dividend: number, modulus: number): number {
    return ((dividend % modulus) + modulus) % modulus;
}