To set a base URL for NodeJS app, we create a router object.
For instance, we write
const express = require("express");
const app = express();
const router = express.Router();
router.use((req, res, next) => {
console.log("%s %s %s", req.method, req.url, req.path);
next();
});
router.use("/bar", (req, res, next) => {
next();
});
router.use((req, res, next) => {
res.send("Hello World");
});
app.use("/foo", router);
app.listen(3000);
to create a router with express.Router.
Then we call use to add the route middlewares.
Next, we call app.use with the base URL and the router to add the routes for the base path.