ffffng/server/shared/utils/strings.ts

/**
 * Utility functions all around strings.
 */
import type { MAC } from "../types";

/**
 * Trims the given `string` and replaces multiple whitespaces by one space each.
 *
 * Can be used to make sure user input has a canonical form.
 *
 * @param str - `string` to normalize.
 * @returns The normalized `string`.
 */
export function normalizeString(str: string): string {
    return str.trim().replace(/\s+/g, " ");
}

/**
 * Normalizes a {@link MAC} address so that it has a canonical format:
 *
 * The `MAC` address will be converted so that it is all uppercase with colon as the delimiter, e.g.:
 * `12:34:56:78:9A:BC`.
 *
 * @param mac - `MAC` address to normalize.
 * @returns The normalized `MAC` address.
 */
export function normalizeMac(mac: MAC): MAC {
    // parts only contains values at odd indexes
    const parts = mac
        .toUpperCase()
        .replace(/[-:]/g, "")
        .split(/([A-F0-9]{2})/);

    const macParts = [];

    for (let i = 1; i < parts.length; i += 2) {
        macParts.push(parts[i]);
    }

    return macParts.join(":") as MAC;
}