/**
 * Thrown when an abortable function was aborted.
 *
 * **Warning**: do not use `instanceof` with this class. Instead, use
 * `isAbortError` function.
 */
export class AbortError implements Error {
  name: 'AbortError' = 'AbortError';
  stack: string = '';

  constructor(
    public message = 'The operation has been aborted',
    captureStackTrace = true,
  ) {
    if (captureStackTrace) {
      Error.captureStackTrace?.(this, this.constructor);
    }

    Object.setPrototypeOf(this, Error.prototype);
  }

  static [Symbol.hasInstance](instance: unknown) {
    return isAbortError(instance);
  }
}

/**
 * Checks whether given `error` is an `AbortError`.
 */
export function isAbortError(error: unknown): error is Error {
  return (
    typeof error === 'object' &&
    error !== null &&
    (error as any).name === 'AbortError'
  );
}

/**
 * If `signal` is aborted, throws `AbortError`. Otherwise does nothing.
 */
export function throwIfAborted(signal: AbortSignal): void {
  if (signal.aborted) {
    throw new AbortError();
  }
}

/**
 * If `error` is `AbortError`, throws it. Otherwise does nothing.
 *
 * Useful for `try/catch` blocks around abortable code:
 *
 *    try {
 *      await somethingAbortable(signal);
 *    } catch (err) {
 *      rethrowAbortError(err);
 *
 *      // do normal error handling
 *    }
 */
export function rethrowAbortError(error: unknown): void {
  if (isAbortError(error)) {
    throw error;
  }

  return;
}

/**
 * If `error` is `AbortError`, does nothing. Otherwise throws it.
 *
 * Useful for invoking top-level abortable functions:
 *
 *    somethingAbortable(signal).catch(catchAbortError)
 *
 * Without `catchAbortError`, aborting would result in unhandled promise
 * rejection.
 */
export function catchAbortError(error: unknown): void {
  if (isAbortError(error)) {
    return;
  }

  throw error;
}