How to structure Express server to use granular API endpoints - node.js

Question

I currently have an Express server I'm using for a mobile app which is structured as follows (server.js):
const PostRouter = require('./api/production/Post');
const UserRouter = require('./api/production/User');
...
app.use('/posts', PostRouter)
app.use('/users', UserRouter)
and then in api/production/Post I have:
router.get('/fetch', (req, res) => {
...
}
router.get('/delete', (req, res) => {
...
}
etc..
However, I would really like to rebuild the server to match the structure of my corresponding NextJS app and its API structure, which would be something like:
/api/posts/
add-post/
index.js
fetch-all/
index.js
edit-post/
index.js
Where each index.js file contains just one endpoint/query instead of the current structure where each file has multiple queries with the router.get thing.
It looks like this is possible by creating a Router for each endpoint with something like:
const PostFetchAllRouter = require('./api/posts/fetch-all');
const PostEditPostRouter = require('./api/posts/edit-post');
...
app.use('posts/fetch-all', PostFetchAllRouter)
app.use('posts/edit-post', PostEditPostRouter)
What would be the best way to do this, please? Is there an easier way to do this without all the boilerplate in the server.js file? I'm very new to Express - please excuse if it's a naive question

Answer 1

You could move the "boilerplate" code to the different router files and build a router chain. But you have to write a little bit more.
server.js
|-api/
|--posts/
|---PostsRouter.js
|---fetchAll.js
|--users/
|---UserRouter.js
fetchAll.js
const express = require("express");
const FetchAll = express.Router();
FetchAll.get("/fetch", (req, res) => { res.send("/posts/fetch") });
module.exports = FetchAll;
PostsRouter.js
const express = require("express");
const FetchAll = require("./fetchAll");
const PostsRouter = express.Router();
PostsRouter.use(FetchAll);
module.exports = PostsRouter;
server.js
const express = require('express');
const PostsRouter = require("./api/posts/PostsRouter");
let app = express();
app.use("/posts", PostsRouter);
app.listen(80, () => {});
If you build it like that you would plug the small routers into the next bigger one and then use them in the server.js.
GET localhost/posts/fetch HTTP/1.1
// returns in my example the string "/posts/fetch"
Is that what you were looking for?