Source: external/task-instance/cancelation.js

export const TASK_CANCELATION_NAME = "TaskCancelation";

/**
 * Returns true if the object passed to it is a TaskCancelation error.
 * If you call `someTask.perform().catch(...)` or otherwise treat
 * a {@linkcode TaskInstance} like a promise, you may need to
 * handle the cancelation of a TaskInstance differently from
 * other kinds of errors it might throw, and you can use this
 * convenience function to distinguish cancelation from errors.
 *
 * ```js
 * click() {
 *   this.myTask.perform().catch(e => {
 *     if (!didCancel(e)) { throw e; }
 *   });
 * }
 * ```
 *
 * @param {Object} error the caught error, which might be a TaskCancelation
 * @returns {Boolean}
 */
export function didCancel(e) {
  return e && e.name === TASK_CANCELATION_NAME;
}

export const CANCEL_KIND_EXPLICIT = "explicit";
export const CANCEL_KIND_YIELDABLE_CANCEL = "yielded";
export const CANCEL_KIND_LIFESPAN_END = "lifespan_end";
export const CANCEL_KIND_PARENT_CANCEL = "parent_cancel";

export class CancelRequest {
  constructor(kind, reason) {
    this.kind = kind;
    this.reason = reason;
    this.promise = new Promise((resolve) => {
      this.finalize = resolve;
    });
  }
}