impl/typescript.ts

// Keep ASCII letters and digits only, then uppercase. Filtering first matters:
// "ß".toUpperCase() is "SS", which would make the SKU depend on how each
// language's Unicode tables treat one letter.
function clean(part: string): string {
  return part.replace(/[^A-Za-z0-9]/g, "").toUpperCase();
}

/**
 * A deterministic SKU: the cleaned prefix and attributes, joined by hyphens.
 * Each attribute is cut to `segmentLength` characters (0 keeps it whole).
 */
export function generateSku(prefix: string, attributes: readonly string[], segmentLength: number): string {
  if (!Number.isInteger(segmentLength) || segmentLength < 0) {
    throw new RangeError(`segmentLength must be 0 or more, received ${segmentLength}`);
  }
  if (attributes.length === 0) {
    throw new RangeError("a SKU needs at least one attribute");
  }
  const parts: string[] = [];
  if (prefix !== "") {
    const cleaned = clean(prefix);
    if (cleaned === "") throw new RangeError(`prefix ("${prefix}") has no letters or digits`);
    parts.push(cleaned);
  }
  attributes.forEach((attribute, index) => {
    const cleaned = clean(attribute);
    if (cleaned === "") {
      throw new RangeError(`attribute ${index + 1} ("${attribute}") has no letters or digits`);
    }
    parts.push(segmentLength === 0 ? cleaned : cleaned.slice(0, segmentLength));
  });
  return parts.join("-");
}