Automatically select port when starting

[franzheidl]

When starting next outputs this:

Ready on http://localhost:3000

Even if something else is already running on 3000. It would be great if next could detect that and then automatically use the next sensible free port (e.g. 3001).

[MoOx]

It would be great if next could detect that and then automatically use the next sensible free port (e.g. 3001).

I am currently using this technique on a project (Phenomic) and I can tell the UX is not the best. Especially if you are already using your own project, just in another terminal/tab and you forget it.

create-react-app is doing something different and tells you that something (and who) is using the port and offer you a way to adjust it.
This UX seems a better choice (source: https://github.com/facebookincubator/create-react-app/blob/dc6edce99bc999252757114cb54721928abc28f1/packages/react-scripts/scripts/start.js#L294-L318)

[franzheidl]

Totally agree! The UX you proposede is in fact better than automatically selecting another port. The thing that is actually bugging me is thatt next.js does not reflect the fact 3000 is already in use, and thus creates output that is simply not correct/misleading.

[arunoda]

Related discussion: #68

[MoOx]

Oh that's exactly this. I guess this issue can be closed then?

[arunoda]

I hope so. Let's talk more on that PR.