TypeScript comparator factory for Array.sort()

create-comparator.ts

// Usage:
const candidates: any[] = [];
// ...
candidates.sort(createComparator(
  (x) => x.ambiguous,
  (_, y) => y.refCount, // DESC
  (x) => x.name.length,
  (x) => x.name,
));

// Source
type ComparatorSelector<T> = (value: T, other: T) => number | string | null;

export function createComparator<T>(...selectors: ComparatorSelector<T>[]) {
  return (a: T, b: T) => {
    for (const selector of selectors) {
      const valA = selector(a, b);
      if (valA === null) continue;
      const valB = selector(b, a);
      if (valB === null || valA == valB) continue;
      if (valA > valB) return 1;
      if (valA < valB) return -1;
    }
    return 0;
  };
}