tildes-reextended/source/utilities/query-selectors.ts

// These utility functions mainly exist so it's easier to work with TypeScript's
// typing and so we don't have to write `document.query...` all the time.

// The first function should only ever be used when we know for certain that
// the target element is going to exist.

/** Returns the first element found that matches the selector. */
export function querySelector<T extends Element>(selector: string): T {
  return document.querySelector(selector)!;
}

/** Returns all elements found from all the selectors. */
export function querySelectorAll<T extends Element>(
  ...selectors: string[]
): T[] {
  return selectors.flatMap((selector) =>
    Array.from(document.querySelectorAll(selector)),
  );
}