kibana/packages/kbn-reporting/common/cancellation_token.test.ts

/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

import { CancellationToken } from './cancellation_token';

describe('Cancellation Token', () => {
  it('registers callbacks for cancellation events', () => {
    const cancellationToken = new CancellationToken();
    const onCancelled = jest.fn();
    cancellationToken.on(onCancelled);
    cancellationToken.cancel();

    expect(onCancelled).toBeCalled();
  });

  it('emits a cancellation event immediately when already cancelled', () => {
    const cancellationToken = new CancellationToken();
    const onCancelled = jest.fn();
    cancellationToken.cancel();
    cancellationToken.on(onCancelled);

    expect(onCancelled).toBeCalled();
  });

  it('binds the `on` method properly so that it can be passed around', () => {
    const cancellationToken = new CancellationToken();
    const onCancelled = jest.fn();
    const unboundOn = cancellationToken.on;

    cancellationToken.cancel();
    unboundOn(onCancelled);

    expect(onCancelled).toBeCalled();
  });

  it('binds the `cancel` method properly so that it can be passed around', () => {
    const cancellationToken = new CancellationToken();
    const onCancelled = jest.fn();
    const unboundCancel = cancellationToken.cancel;

    unboundCancel();
    cancellationToken.on(onCancelled);

    expect(onCancelled).toBeCalled();
  });
});