Variable '${file}' can not be resolved. Please open an editor

[ahue]

Observed behavior

Created a task in tasks.json to execute tests in the current open file using pytest.

{
      "label": "run file tests",
      "type": "ssh-shell",
      "host": "my-host",
      "command": "pytest ${file}",
}

On running the task, I get the error Variable ${file} can not be resolved. Please open an editor.

Same behavior with other file-reated variable placeholders, see https://code.visualstudio.com/docs/editor/variables-reference

• ${file} - the current opened file
• ${fileWorkspaceFolder} - the current opened file's workspace folder
• ${relativeFile} - the current opened file relative to workspaceFolder
• ${relativeFileDirname} - the current opened file's dirname relative to workspaceFolder
• ${fileBasename} - the current opened file's basename
• ${fileBasenameNoExtension} - the current opened file's basename with no file extension
• ${fileDirname} - the current opened file's dirname
• ${fileExtname} - the current opened file's extension

Expected behavior

${file} is replace with the absolute path of the file on the host.

System info SSH FS version: v1.19.1 VSCode version: 1.52.1 OS: Windows 10 10.0.19041

[SchoofsKelvin]

I've look a bit into it, and this might be a bug on their end. This error gets thrown before my extension receives the resolved task definition. It might be worthwhile opening an issue in microsoft/vscode to support ${file} and such for editors for FileSystemProvider files.

At first glance, one possible solution is intercepting the variables before the task definition gets resolved, and replacing them with placeholders I can resolve later. I did run a quick check and noticed that I can see the current editor and which (remote) file it opens, so this seems technically feasible.

This would "fix" ${file} and similar, but only for ssh-shell tasks. Other tasks trying to use ${file} for remote files will still error, nothing I can do about that. Another solution is not touching the built-in variables, and adding my own instead, e.g. ${remoteFile}. I'm more inclined towards the first solution, though, although nothing stops me from doing both.

I have exams now, one being in less than a week, so it might take a while.

[SchoofsKelvin]

I've looked a bit more into it, and I've stumbled on a big roadblock regarding the first solution: Modifying/replacing the task definition my extension receives breaks the whole task providing process. This means I can't actually replace ${file} with ${remoteFile} and such before VS Code tries to resolve it and thus errors.

I'll still add ${remoteFile} and such, that just means you can't use the built-in ${file} ones, or at least they won't be properly mapped. Again, those variables would only work for ssh-shell tasks. Alternatively I could add support for ${command:sshfs.pickRemoteFolder} or something similar, but that'd be something for later.

[SchoofsKelvin]

Pull request in vscode got merged, once it's released (I assume 1.54.0, maybe 1.53.1) I'll continue working on this.

[SchoofsKelvin]

This is now added in v1.20.0 of the extension. You should be able to use ${remoteFile} once you've updated to v1.20.0 or later.