src/vs/workbench/services/configuration/browser/configurationService.ts/WorkspaceService/getWorkbenchState
class WorkspaceService:	public getWorkbenchState(): WorkbenchState {
		// Workspace has configuration file
		if (this.workspace.configuration) {
			return WorkbenchState.WORKSPACE;
		}

		// Folder has single root
		if (this.workspace.folders.length === 1) {
			return WorkbenchState.FOLDER;
		}

		// Empty
		return WorkbenchState.EMPTY;
	}