workspaceFolder variable substitution in launch.json or tasks.json should use URI for virtual filesystems

[zobo]

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

• VS Code Version: 1.84.0 (user setup)
• OS Version: Windows_NT x64 10.0.22621

Steps to Reproduce:

1. Install a remote virtual filesystem extension like Kelvin.vscode-sshfs or liximomo.remotefs
2. When connected to a remote FS, create a remote launch.json and use ${workspaceFolder} somewhere where it will be replaced - the same can be seen with a remote tasks.json
3. The variable is replaced not with it's URI form but with its fsPath form.

Here is an example tasks.json than can quickly reproduce the issue. Note the options.cwd.

{
	"version": "2.0.0",
	"tasks": [
	  {
		"label": "echo 2",
		"type": "shell",
		"options": {
			"cwd": "c:\\temp"
		},
		"command": "echo ${workspaceFolder}"
	  }
	]
  }

And a xdebug.php-debug specific launch.json.

{ "version": "0.2.0", "configurations": [ 
	{ 
		"name": "Listen for Sail Xdebug", 
		"debugServer": 4711,
		"type": "php", 
		"request": "launch", 
		"port": 9003, 
		"pathMappings": { "/var/www/html": "${workspaceFolder}" }, 
		// "pathMappings": { "/var/www/html": "ssh://docker.local/users/zobo/laravel-test" }, 
	}
]}

Additional info.

In the specific case of debugging a remote PHP script - mounted over SSHFS virtual filesystem, this is needed so that the php-debug adapter can convert a /var/www/html/index.php path to a VFS uri of ssh://users/zobo/laravel-test/index.php.

I have added the virtualWorkspaces capability, but that did not help. I believe this is the offending code:

vscode/src/vs/workbench/services/configurationResolver/common/variableResolver.ts

Lines 285 to 287 in dc78919

	case 'workspaceRoot':
	case 'workspaceFolder':
	return normalizeDriveLetter(this.fsPath(getFolderUri(VariableKind.WorkspaceFolder)));

Related php-debug issue: xdebug/vscode-php-debug#873
Related docs https://code.visualstudio.com/api/extension-guides/virtual-workspaces

Example XXX.code-workspace config for sshfs and remotefs

{
	"folders": [
		{
			"name": "example-app — (Remote)",
			"uri": "sftp://dockerrfs/"
		},
		{
			"path": ".."
		},
		{
			"name": "SSH FS - docker",
			"uri": "ssh://users/zobo/laravel-test"
		}
	],
	"settings": {
		"sshfs.configs": [
			{
				"name": "docker",
				"host": "192.168.56.101",
				"username": "root",
				"root": "/users/zobo/laravel-test",
				"agent": "pageant"
			}
		],
		"remotefs.remote": {
			"dockerRFS": {
				"scheme": "sftp",
				"host": "192.168.56.101",
				"username": "root",
				"rootPath": "/users/zobo/laravel-test",
				"agent": "pageant"
			}
		}
	}
}

I could solve the problem by implementing this in the php-debug resolveDebugConfiguration

                if (folder && folder.uri.scheme !== 'file') {
                    // replace 
                    if (debugConfiguration.pathMappings) {
                        for (const key in debugConfiguration.pathMappings) {
                            debugConfiguration.pathMappings[key] = debugConfiguration.pathMappings[key].replace('${workspaceFolder}', folder.uri.toString())
                        }
                    }
                }

(This just replaces the variable in one specific key, should be everywhere...)

Label: debug

[roblourens]

Hm... maybe would need a new variable for that?

[zobo]

Maybe. But probably does not make sense to resolve it with fsPath when it's not a file://. At least this is how I read the first point from here https://code.visualstudio.com/api/extension-guides/virtual-workspaces#review-that-the-extension-code-is-ready-for-virtual-resources

[alexr00]

@zobo you're correct that we shouldn't be doing fsPath when the scheme isn't file. However, I'm worried that some users may have come to depend on it. Here's what I propose we try:

• Stop using fsPath for non file schemes in VS Code insiders.
• If no one brings issues about this for a few months, then we can release to stable.

I don't want to just keep it in insiders for one month since this is a niche use case and I think we'll miss some users.

[zobo]

Hi @alexr00 !

Sounds good - although as you said - it's very niche so it's questionable if any of those users even use Insiders...
In whatever timeline, I think this should be changed for non file:// schemas. And probably advertised as braking change.

Another thing is what Rob said. Maybe, in addition, another variable (maybe ${workspaceFolder:uri}) could be introduced. Not so much for solving the problem with VFS, but giving the user a way to get an URI even for file:// files.

How that is useful is actually a valid question that I don't have an answer to.

As always, adding is easy, taking away is nearly impossible. Add with caution.