URLManifestItem.url shouldn't contain non-URL-unit characters

[gsnedders]

Rendered

[gsnedders]

(There's also the variant of this RFC where all we do is url.replace(" ", "%20") which avoids the "space separated URLs" problem. But it still carries the same risks.)

[foolip]

One question here is whether we should disallow test file paths that contain spaces, or whether we should just escape these in the URL.

Given how few such files there are, let's just disallow them.

[jgraham]

Storing URLs (and therefore test ids) in url-encoded form does make sense.

Migrating expectation data is a challenge. I wonder if for the wpt expectation files (which handle spaces fine) we could just unencode the test id before using the manifest? That makes it more likely that the manifest will match whatever people write in the <meta name=varaint>. Alternatively if we're going to change to using the URL encoded form everywhere, I think we should have a lint to ensure we use it consistently (maybe we should have a lint either way, so that we don't get %20 in some places and in another).

I don't think banning spaces in test names is worthwhile.

[foolip]

I don't think banning spaces in test names is worthwhile.

I just searched for spaces in filenames and found two cases that don't seem intentional:

web-platform-tests/wpt#46253
web-platform-tests/wpt#46254

Is there much of a downside to banning spaces?