vscode.workspace.showSaveDialog not returning full URI in VSCode web

[gbrueckl]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.99.2
  Commit: 4949701
  Date: 2025-04-10T01:21:25.295Z
  Browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36 Edg/135.0.0.0
• OS Version: Windows 11

Steps to Reproduce:

1. have an extension that uses vscode.window.showSaveDialog
2. use that extension in VSCode web
3. print the URI returned by vscode.window.showSaveDialog

Expected Result: file:///d%3A/someFolder/myFile.txt

Actual Result: file:///myFile.txt

I tested this with Edge browser as interaction with the local file system is only supported with Edge and Chrome: https://code.visualstudio.com/docs/remote/codespaces#_how-do-i-allow-vs-code-in-a-browser-to-access-local-files-and-folders

[bpasero]

To my knowledge, the web does not expose full file paths.

[vs-code-engineering]

This feature request is now a candidate for our backlog. The community has 60 days to upvote the issue. If it receives 20 upvotes we will move it to our backlog. If not, we will close it. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!

[gbrueckl]

this is actually supposed to be a bug report and not a feature request. According to the link browsers (Edge and Chrome) should be able to access the local file system. What would be the point in accessing/browsing the local file system if the output that is returned does not reflect what was selected?!

[bpasero]

Please see https://developer.mozilla.org/en-US/docs/Web/API/FileSystemHandle, FileSystemHandle only carry a name and not the full path, probably for security/privacy reasons.

[gbrueckl]

ok, got it - so this is actually an issue with the browser API (=File System API) which VSCode relies on

but doesnt this render this API useless at some point? for VSCode and also all other users of these APIs?

[bpasero]

Yes, this is a browser limitation we are unlikely to workaround. We can get relative paths, from the root, but not absolute paths.

You can see what is possible if you open a local folder on https://vscode.dev where we use the local file system API.

[gbrueckl]

so seems like technically you could do everything within the root path you have loaded into VSCode. E.g. Copy files and folders, modify/create/Delete, etc.
I also tried to select a path under the root-path in the Save-dialog (vscode.window.showSaveDialog) but this also did not work.
To make this work I guess you would need to pass a root-path also to the SaveDialog. It could be derived from the current workspace settings/folders or throw an error if no local folder is loaded yet