ReferenceError：结果未在节点js中定义

Question

我正在实现一个聊天机器人，该聊天机器人会根据用户输入提供一些信息。我正在通过node调用python脚本并获取数据，而在尝试将此数据发送回Slack时遇到了此错误。我不确定如何将数据从一个异步函数发送到另一个异步函数，或者如何将结果回调到processTextAndRespond。这是我遇到的错误-

An error occurred ReferenceError: result is not defined
    at postMessage (C:\Users\)
    at processTextAndRespond

这是代码：

rtm.on('message', (event) => {
    // console.log(event);
    if(!event.subtype){

        processTextAndRespond(event.text,event.user,event);

    }else{
        console.log('nothing to do !!!');
    }
});

const processTextAndRespond = async function(userText,userName,event){
    processData(userText);

    postMessage(answer);

};

const postMessage = async function(answer,event){
try {

console.log("Working");
       processData(result);
       const answer = await rtm.sendMessage(result, event.channel);
       return answer;
} catch (error) {
    console.log('An error occurred', error);
  }
};

const processData = async function(userText,result) {
   const childProcess = require("child_process").spawn('python', ['./search.py', userText], {stdio: 'inherit'})
    childProcess.on('data', function (data) {
         process.stdout.on("python script output", data)
              result = data.toString()