import { eachSeries } from 'async' import { NextFunction, Request, RequestHandler, Response } from 'express' import { retryTransactionWrapper } from '../helpers/database-utils' import { ValidationChain } from 'express-validator' // Syntactic sugar to avoid try/catch in express controllers // Thanks: https://medium.com/@Abazhenov/using-async-await-in-express-with-node-8-b8af872c0016 export type RequestPromiseHandler = ValidationChain | ((req: Request, res: Response, next: NextFunction) => Promise) function asyncMiddleware (fun: RequestPromiseHandler | RequestPromiseHandler[]) { return (req: Request, res: Response, next: NextFunction) => { if (Array.isArray(fun) === true) { return eachSeries(fun as RequestHandler[], (f, cb) => { Promise.resolve(f(req, res, cb)) .catch(err => next(err)) }, next) } return Promise.resolve((fun as RequestHandler)(req, res, next)) .catch(err => next(err)) } } function asyncRetryTransactionMiddleware (fun: (req: Request, res: Response, next: NextFunction) => Promise) { return (req: Request, res: Response, next: NextFunction) => { return Promise.resolve( retryTransactionWrapper(fun, req, res, next) ).catch(err => next(err)) } } // --------------------------------------------------------------------------- export { asyncMiddleware, asyncRetryTransactionMiddleware }