[v5] Suggestion for migrating wildcard paths handling

[RecuencoJones]

TL;DR: Simply use

app.get([ '/files/', '/files/*param0' ], (req, res) => {
  const requestPath = req.params.param0?.join('/') || '/';
  ...
});

Original post

Due to the updates on router and path-to-regex, handling wildcard routes requires a bit of work on the parameters to bring them back to the same values v4 produces when matching routes.

I found this code should work similarly and may help people migrate their routes if they expect variable file / folder paths:

import { join, sep } from 'path/posix';

function normalizeWildcardParamToPath(segments) {
  if (!Array.isArray(segments)) {
    return;
  }

  const _segments = segments.map((segment) => segment === '' ? sep : segment);

  return join(..._segments);
}

app.get([ '/files/', '/files/*param0' ], (req, res) => {
  const requestPath = normalizeWildcardParamToPath(req.params.param0) || sep;
  ...
});

I thought simply using join() would be enough, but when matching folders (e.g, /files/folder/), req.params.param0 would be [ 'folder', '' ] and join() ignores the empty string value 😩

[wesleytodd]

Ideally if you are using this for file access like in your example you would be more careful about it than just joining the string and reading from disk (ex. not exposing your file structure directly to the client). If you need a static file server, I suggest nginx not express, but if you really want to we have .static() and serve-static for this.

[RecuencoJones]

Absolutely, however our use case is not about serving static files available in the server but accessing some cloud storage with a set of middlewares for permissions, asset optimization... where the file path can be variadic (otherwise we might just use regular param matchers)

[wesleytodd]

Good, just wanted to make the comment in case beginners came upon this suggestion and were unaware. As for the rest, I would look at Blake's answer below, because simplicity is usually the best option and if you really need the trailing slash you can use req.url as well.

[blakeembrey]

To achieve the old result, it should be enough to do param0.join("/"). Keep in mind that this treats / and %2F as the same, which may be fine for you.

[RecuencoJones]

Can I be so blind I just didn't think of this first? 🤦‍♂️🤦‍♂️🤦‍♂️

We have so many usages of path.posix.join() I couldn't just think of using Array.join()

Thanks, I'll update the example above to avoid confusing people more than necessary