Add a new regexp to also match uri in the form /proxy/{{port}}

[micedre]

closes #14595

Description

This PR add a pattern to match, used with the preview subcommand to reload the page

Checklist

I have (if applicable):

• referenced the GitHub issue this PR closes
• updated the appropriate changelog in the PR
• ensured the present test suite passes
• added new tests
• created a separate documentation PR in Quarto's website repo and linked it to this PR

[posit-snyk-bot]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.

[cderv]

Thanks for the fix.

The new pattern looks right for code-server — /proxy/{port}/ and /absproxy/{port}/ are both valid code-server proxy URL formats, so matching both with (?:abs)? makes sense.

I want to get sign-off from the Positron team before merging, since this area has known interactions with the VS Code extension (@cscheid flagged this in the issue).

For reference from what I found:

• Positron doesn't use VSCODE_PROXY_URI — it builds its own proxy — and its format is also /proxy/{port}/ on desktop, so the new pattern covers it correctly.
  The Workbench path (/p/{token}/) was already matched by the first regex.

No regression expected, but they should still be aware of the change.

@vezwork asking you for the Quarto VSCODE extension in case you see anything. And do you know who is best fit in positron team to ask ? I'll probably slack them.

[vezwork]

I don't see anything obvious, I don't see how this could cause issues. Probably @juliasilge is the best person I know to ask.

[juliasilge]

Here is my understanding of what is going with this fix:

Posit Workbench (Positron Pro / VS Code sessions) should be unaffected

Workbench reverse-proxies sessions under a /p/<id>/ path, which is already captured by the existing first alternative (/^.*?\/p\/\w+\//). This PR adds a new alternative but does not change that one, so reload behavior in Workbench is unchanged. Like @cderv noted, Positron does not read VSCODE_PROXY_URI at all. It detects the Workbench context via the RS_SERVER_URL env var and resolves preview URLs through vscode.env.asExternalUri(), so the /p/<id>/ prefix is what reaches the browser, not a proxy path derived from VSCODE_PROXY_URI.

Positron Desktop should be unaffected

In the desktop app, asExternalUri() is effectively identity, so a previewed app stays at http://127.0.0.1:<port>/ with no /proxy/<n>/ segment in the path. None of the three regex alternatives match, so it falls through to a plain window.location.reload(), same as today.

Positron Server Web (like in JupyterHub) is newly matched, and likely a fix!

Here Positron forwards previews through its own proxy and produces external URLs of the form .../proxy/<port>/.... The existing two patterns did not match that shape, so reloads dropped the prefix, the same bug being reported here. The new /^.*?\/(?:abs)?proxy\/\d+\// alternative should now match and fix it in this environment too.

I don't know if we have the ability to test this in Positron Server on JupyterHub before merging (a pretty high lift) so I think we should go for it and look for any regressions. We do have some automated testing on the Positron side for JupyterHub.

cc @testlabauto and @isabelizimm for visibility on this upcoming change to the Quarto CLI, which I believe would fix problems with quarto preview for Positron in JupyterHub. I bet we just test quarto render right now, so mostly as a heads up!

[cderv]

Thank you ! I will merge this and make a new 1.10 build so you can test.

We're not close to release 1.10 so we have time to revert or adapt.