How do I expand VS Code variables used in settings?

[brobeson]

It's possible for VS Code settings to use variables:

{
  "cmake.buildDirectory": "${workspaceFolder}/../build"
}

When I fetch the setting value, I get the literal text ${workspaceFolder}:

const build_directory = vscode.workspace.getConfiguration("cmake")
  .get("buildDirectory");
// build_directory === "${workspaceFolder}/../build"

How can I ask VS Code to evaluate the variable? I haven't found anything in the extension API. I did find the vscode-variables package, but I couldn't get it to work.

[default-writer]

Please take a look of how you can parse and process environment varialbles as well as visual studio code default variables:

Predefined Variables in test commands

The following predefined variables are supported:

${workspaceFolder} - the path of the folder opened in VS Code
${workspaceFolderBasename} - the name of the folder opened in VS Code without any slashes (/)
${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
${fileExtname} - the current opened file's extension
${fileDirname} - the current opened file's folder path
${fileDirnameBasename} - the current opened file's folder name
${env:NAME} - reference environment variables through the ${env:Name} syntax

https://github.com/default-writer/filetestonsave/blob/main/src/extension.ts