src/vs/editor/contrib/snippet/browser/snippetVariables.ts/WorkspaceBasedVariableResolver/_resoveWorkspacePath
class WorkspaceBasedVariableResolver:	private _resoveWorkspacePath(workspaceIdentifier: IWorkspaceIdentifier | ISingleFolderWorkspaceIdentifier): string | undefined {
		if (isSingleFolderWorkspaceIdentifier(workspaceIdentifier)) {
			return normalizeDriveLetter(workspaceIdentifier.uri.fsPath);
		}

		const filename = path.basename(workspaceIdentifier.configPath.path);
		let folderpath = workspaceIdentifier.configPath.fsPath;
		if (folderpath.endsWith(filename)) {
			folderpath = folderpath.substr(0, folderpath.length - filename.length - 1);
		}
		return (folderpath ? normalizeDriveLetter(folderpath) : '/');
	}