Express route param is undefined when I use express.Router()

[ItsRealmy]

So imagine if the current file I'm in is an express.Router() for the endpoint /post.

I tried to require a different router within the /post router called /:id (which is a url param), sorta like this: router.use("/:id", require("./idRouter"));. So, if I go to idRouter.js (which' route is /post/:id) and write something like this:

router.get("/like", (req, res) => {
  console.log(req.params.id)
  res.send({status:"SUCCESS"});
});

And then if I go to the endpoint in a browser (for example /post/12345/like) it does respond with {"status":"SUCCESS"} but req.params.id is undefined, so I can't use it. Is this a bug or is this deliberate (for some reason)?

Note: req.params is an empty object

[dougwilson]

You need to create your Router with mergeParams: true if you want params in the parent router to be visible in that child router. https://expressjs.com/en/api.html#express.router