如何修复try/catch中Slack Webhook的未处理Promise拒绝错误

这问题我之前也碰到过，核心原因是你没搞清楚webhook.send()的异步特性——它返回的是一个Promise对象，而你用的同步try/catch只能捕获同步代码里的错误，根本抓不到Promise被拒绝（reject）的情况，所以你的catch块完全没触发，错误直接变成了未处理的Promise拒绝。

解决方案1：用async/await配合try/catch（推荐，代码更清晰） #

把你的逻辑包裹在一个async函数里，用await等待webhook.send()完成，这样同步的try/catch就能正常捕获Promise的错误了。

修改后的完整代码示例：

const TOTAL_GHE_ISSUES = "10"; // pulled from DB
const GHE_ISSUE_NUMBERS = "90"; // pulled from DB
const IncomingWebhook = require('@slack/webhook').IncomingWebhook;

// 把所有逻辑放到async函数里
async function sendSlackAlert() {
  var url = SLACK_WEBHOOK_URL;
  var webhook = new IncomingWebhook(url);

  if (url !== "") {
    if (TOTAL_GHE_ISSUES !== "0") {
      try {
        // 用await等待异步操作完成
        await webhook.send({
          text: "*Daily Overdue Nessus Vulnerability Alert*",
          attachments: [{
            color: "#FF0000",
            blocks: [{
              type: "section",
              text: {
                type: "mrkdwn",
                text: "@here *" + TOTAL_GHE_ISSUES + "* Overdue Nessus Vulnerability issues reported \nOverdue Nessus Vulnerability GHE Issue Numbers: *" + GHE_ISSUE_NUMBERS + "*"
              }
            }]
          }]
        });
      } catch(err) {
        console.log("Webhook Verification Failed", err);
        // 向监控频道发送告警，重新创建实例更稳妥
        const monitoringWebhook = new IncomingWebhook(SLACK_MONITORING_URL);
        await monitoringWebhook.send({
          text: "*Nessus Webhook Verification, please investigate broken webhooks:*",
          attachments: [{
            color: "#FF0000",
            blocks: [{
              type: "section",
              text: {
                type: "mrkdwn",
                text: `Broken webhook URL: *${SLACK_WEBHOOK_URL}*`
              }
            }]
          }]
        });
      }
    } else {
      try {
        await webhook.send({
          text: "*Daily Overdue Nessus Vulnerability Alert*",
          attachments: [{
            color: "#36a64f",
            blocks: [{
              type: "section",
              text: {
                type: "mrkdwn",
                text: "@here *NO* Overdue Nessus Vulnerabilities reported"
              }
            }]
          }]
        });
      } catch(err) {
        console.log("Webhook Verification Failed", err);
        const monitoringWebhook = new IncomingWebhook(SLACK_MONITORING_URL);
        await monitoringWebhook.send({
          text: "*Nessus Webhook Verification, please investigate broken webhooks:*",
          attachments: [{
            color: "#FF0000",
            blocks: [{
              type: "section",
              text: {
                type: "mrkdwn",
                text: `Broken webhook URL: *${SLACK_WEBHOOK_URL}*`
              }
            }]
          }]
        });
      }
    }
  } else {
    console.log("No webhook provided");
  }
}

// 调用async函数，同时捕获顶层可能的错误
sendSlackAlert().catch(err => console.error("Top-level error:", err));

解决方案2：用Promise的.catch()方法 #

如果你暂时不想用async/await，也可以直接在webhook.send()后面链式调用.catch()来处理错误，比如：

webhook.send({
  // 你的消息内容
}).catch(err => {
  console.log("Webhook Verification Failed", err);
  // 处理监控频道告警
  const monitoringWebhook = new IncomingWebhook(SLACK_MONITORING_URL);
  monitoringWebhook.send({/* 监控消息内容 */}).catch(err => console.error("Monitoring webhook failed:", err));
});

额外小提醒 #

1. 不要重复复用同一个webhook实例发送不同频道的消息，每次发送新频道都重新创建IncomingWebhook实例更稳妥。
2. 错误处理里最好把错误详情也打印出来（比如console.log("Webhook Verification Failed", err)），方便排查具体问题（比如URL无效、网络错误还是Slack返回的其他异常）。

内容的提问来源于stack exchange，提问作者Brandon Konieczny