AsyncFunction = Object.getPrototypeOf(async function () {}).constructor;

function str2AsyncFunction(
  contents: string,
  ...args: Array<string>
): Function | null {
  try {
    let fn = new AsyncFunction(...args, contents);
    return fn;
  } catch (e) {
    console.warn(e);
    return null;
  }
}

str2AsyncFunction(scriptFuncStr, 'context', 'doAction', 'event');