File Based Routing for Express Backend

To install z-file-router, open your terminal and paste the following command

npm i z-file-router

yarn add z-file-router

[!NOTE] I have give example of typescript but the same is applicable for javascript

Your project structure should look like this to enable file based routing

Project/
├── node_modules/
└── src/
|  /* your other folders */
|  ├── services/
|  |  ├── user
|  |  |  ├── index.ts      // required
|  |  |  ├── middleware.ts // optional
|  |  |  ├── model.ts      // optional
|  |  |  └── validate.ts   // optional
|  |  /* other services */
|  └── index.ts // stating point of your app
├── .gitignore
├── package.json
├── package-lock.json
├── README.md
└── tsconfig.json

[!NOTE]

• There must be a folder named services in same level as main index.ts file for file based routing to work.
• Service name inside services folder will be the endpoint for calling APIs.
• Every service must have an index.ts file associated with it.

[!TIP] It is best practice to make a model.ts file for creating DB model for the respective service and a validate.ts file for validating payload. Use library like zod or joi for validating payload

To call one service into another service

z-file-router also gives Services.get() static method to call one service into another service

Services.get('service-name').find(query,req);

Here is your main index.ts file

import express from "express";
import { RouteLoader } from "z-file-router";

const app = express();

new RouteLoader({ app, port: 3000 });

RouterLoader constructor takes following parameter as an object

• app (express) - this is express function
• port (number) - port number (default port is 3000)
• limit (string) - the maximum size of the JSON payload that the server will accept
• listen (boolean) - false if you want to handle server start by yourself (by default its true, means server will start as soon as you call the RouteLoader constructor)

[!NOTE]

• app.listen() and middleware express.json() is already handled by the RouteLoader constructor
• if you have done listen equals false in RouteLoader contructor, you must write your own logic for starting server after calling RouteLoader class

Now create a folders inside services folder and name it as user create index.ts file for it

/services/user/index.ts

export class UserService {
  async find(query: Record<string, any>, req: Record<string, any>) {
    // do your logic here
    return {
      query,
    };
  }

  async get(id: string, query: Record<string, any>, req: Record<string, any>) {
    // do your logic here
    return {
      id,
      query,
    };
  }

  async post(
    body: Record<string, any>,
    query: Record<string, any>,
    req: Record<string, any>
  ) {
    // do your logic here
    return {
      body,
      query,
    };
  }

  async patch(
    id: string,
    body: Record<string, any>,
    query: Record<string, any>,
    req: Record<string, any>
  ) {
    // do your logic here
    return {
      id,
      body,
      query,
    };
  }

  async remove(
    id: string,
    query: Record<string, any>,
    req: Record<string, any>
  ) {
    // do your logic here
    return {
      id,
      query,
    };
  }

  async update(
    id: string,
    body: Record<string, any>,
    query: Record<string, any>,
    req: Record<string, any>
  ) {
    // do your logic here
    return {
      id,
      body,
      query,
    };
  }
}

[!IMPORTANT] Each service's index.ts file will have 6 functions exposed - find, get, post, patch, update, remove | FUNCTION | REQUEST | ENDPOINT | ARGUMENTS | |:---------|:--------|:------------------ |:----------------------| | find | GET | /{service} | query, req | | get | GET | /{service}/:id | id, query, req | | post | POST | /{service}/ | body, query, req | | patch | PATCH | /{service}/:id | id, body, query, req | | update | PUT | /{service}/:id | id, body, query, req | | remove | DELETE | /{service}/:id | id, query, req |

If you want to add middleware in specific route or all route, add a middlware.ts file in the respective service folder

[!NOTE]

• middleware.ts file is optional.
• Middleware file name must be middleware.ts for middlewares to get applied.
• Middleware class must be default exported.

[!IMPORTANT]

• (all) - to apply middleware to all routes
• (find, get, post, patch, update, remove) - to apply middleware to respective route

services/user/middleware.ts

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

function auth(req: Request, res: Response, next: NextFunction) {
  // do your logic here
  console.log("user auth middleware");
  next();
}

export default class UserMiddleware {
  private all = [auth];
}