Applies routes

index.ts

import { Router, Request, Response, NextFunction } from "express";

type Wrapper = ((router: Router) => void);

export const applyMiddleware = (
  middlewareWrappers: Wrapper[],
  router: Router
) => {
  for (const wrapper of middlewareWrappers) {
    wrapper(router);
  }
};

type Handler = (
  req: Request,
  res: Response,
  next: NextFunction
) => Promise<void> | void;

type Route = {
  path: string;
  method: string;
  handler: Handler | Handler[];
};

export const applyRoutes = (routes: Route[], router: Router) => {
  for (const route of routes) {
    const { method, path, handler } = route;
    (router as any)[method](path, handler);
  }
};

Thanks for your great post!

Improvement: You can avoid casting the router to any if you make the methods explicit, e.g. (using all available routes types in the docs),

type Route = {
  path: string;
  method: 'checkout' | 'copy' | 'delete' | 'get' | 'head' | 'lock' | 'merge' | 'mkactivity' | 'mkcol' | 'move' | 'm-search' | 'notify' | 'options' | 'patch' | 'post' | 'purge' | 'put' | 'report' | 'search' | 'subscribe' | 'trace' | 'unlock' | 'unsubscribe';
  handler: Handler | Handler[];
};