Static files with spaces or underscores in the file name don't work with adapter-node

[PaulHobbs]

Describe the bug
Static files with a space or underscores don't get served by adapter-node.

Logs
No logs available, just a 404 from the node server.

To Reproduce
Add a static file with a space in it, like so: PaulHobbs@28ce49c

The file will be served correctly from the dev server, but return a 404 from the built node server (when run with npm run build && cd build && node .).

Expected behavior
Static with spaces should be served by the built node server correctly.

Stacktraces
N/A

Information about your SvelteKit Installation:

• The output of npx envinfo --system --npmPackages svelte,@sveltejs/kit --binaries --browsers

  System:
    OS: macOS 11.0.1
    CPU: (8) arm64 Apple processor
    Memory: 117.89 MB / 16.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 15.5.1 - /opt/homebrew/bin/node
    npm: 7.3.0 - /opt/homebrew/bin/npm
  Browsers:
    Chrome: 89.0.4389.90
    Firefox: 86.0.1
    Safari: 14.0.1

• Your browser
  Tested with Chrome and curl.

• Your adapter (e.g. Node, static, Vercel, Begin, etc...)
  Node

Severity
Blocking an upgrade from Sapper to SvelteKit. I have a site with extensive use of static files with spaces, and the file names are used semantically (to determine the titles of the images), so removing the spaces is not an option.

Additional context

[samccone]

Reducing the problem a bit I can confirm that sirv is not correctly handling the decoding of URL paths
https://github.com/lukeed/sirv/blob/master/packages/sirv/index.js#L163

Example request:
http://localhost:3000/a%20space.png

If I change the above line to

		let pathname = decodeURI(req.path || parser(req, true).pathname);

Things begin to work.

plussing in @lukeed for visibility. That said I am 99% sure this is a issue upstream that we should patch
https://github.com/lukeed/sirv

[samccone]

Interestingly I added a new test case upstream for sirv and can confirm it is handling this case correctly
lukeed/sirv#102

[samccone]

The reason why sivr is working is that req.path is unset, and thus it falls into the parser code which handles the decoding of the URL.

let pathname = req.path || parser(req, true).pathname;

// req.path
`undefined` 

// parser(req, true).pathname
/with space.txt

[lukeed]

Kit fails because req.path is set, coming from Polka (stable) which doesn't decode upfront. Either add an inline middleware to manually decode before the assets middleware is run, or override app.parse, or use polka@next which decodes by default.

[samccone]

Thanks @lukeed looks like I was on the right path :)
#743

[lukeed]

Indeed!