export function onDispatchHandler()

in src/common/providers/https.ts [833:877]

• 36 lines of code
• 6 McCabe index (conditional complexity)

export function onDispatchHandler<Req = any>(
  handler: v1TaskHandler | v2TaskHandler<Req>
): (req: Request, res: express.Response) => Promise<void> {
  return async (req: Request, res: express.Response): Promise<void> => {
    try {
      if (!isValidRequest(req)) {
        logger.error('Invalid request, unable to process.');
        throw new HttpsError('invalid-argument', 'Bad Request');
      }

      const context: TaskContext = {};
      const status = await checkAuthToken(req, context);
      // Note: this should never happen since task queue functions are guarded by IAM.
      if (status === 'INVALID') {
        throw new HttpsError('unauthenticated', 'Unauthenticated');
      }

      const data: Req = decode(req.body.data);
      if (handler.length === 2) {
        await handler(data, context);
      } else {
        const arg: TaskRequest<Req> = {
          ...context,
          data,
        };
        // For some reason the type system isn't picking up that the handler
        // is a one argument function.
        await (handler as any)(arg);
      }

      res.status(204).end();
    } catch (err) {
      if (!(err instanceof HttpsError)) {
        // This doesn't count as an 'explicit' error.
        logger.error('Unhandled error', err);
        err = new HttpsError('internal', 'INTERNAL');
      }

      const { status } = err.httpErrorCode;
      const body = { error: err.toJSON() };

      res.status(status).send(body);
    }
  };
}