freddi301/flow-validator

// @flow

import { Type } from "./Type";
import type { Middleware, $Response, NextFunction } from "express";

function middleware<T>(
  validator: Type<T>,
  fun: (req: T, res: $Response, next: NextFunction) => mixed
): Middleware {
  return (req, res, next) => {
    try {
      const data = validator.parse(req);
      fun(data, res, next);
    } catch (e) {
      next(e);
    }
  };
}

function requestMapping<T>(
  validator: Type<T>,
  fun: (req: T, res: $Response) => mixed
): Middleware {
  return (req, res, next) => {
    try {
      const data = validator.parse(req);
      fun(data, res);
    } catch (e) {
      next();
    }
  };
}

function endpoint<T>(
  validator: Type<T>,
  fun: (req: T, res: $Response) => mixed
): Middleware {
  return (req, res, next) => {
    try {
      const data = validator.parse(req);
      fun(data, res);
    } catch (e) {
      next(e);
    }
  };
}

export const express = { endpoint, middleware, requestMapping };