Method doUnsubscribe

packages/service-worker/src/push.ts:267–286

(sub: PushSubscription | null)

    }

    const doUnsubscribe = (sub: PushSubscription | null) => {
      if (sub === null) {
        throw new RuntimeError(
          RuntimeErrorCode.NOT_SUBSCRIBED_TO_PUSH_NOTIFICATIONS,
          (typeof ngDevMode === 'undefined' || ngDevMode) &&
            'Not subscribed to push notifications.',
        );
      }

      return sub.unsubscribe().then((success) => {
        if (!success) {
          throw new RuntimeError(
            RuntimeErrorCode.PUSH_SUBSCRIPTION_UNSUBSCRIBE_FAILED,
            (typeof ngDevMode === 'undefined' || ngDevMode) && 'Unsubscribe failed!',
          );
        }

        this.subscriptionChanges.next(null);
      });
    };

    return new Promise((resolve, reject) => {
      this.subscription