JavaScript TypeError

Question

当我测试我的aws lambda时，我得到了一个TypeError:无法读取未定义的属性'0‘。代码是

'use strict';

const snsPublisher = require('./snsPublisher');

exports.handler = (event, context, callback) => {
    //console.log('Received event:', JSON.stringify(event, null, 2));
    const message = event.Records[0].Sns.Message;
    console.log('From SNS:', message);
    callback(null, message);
};

module.exports.snsLamdbaTriggered = (event, context, callback) => {
  var topic = event.Records[0].Sns.TopicArn;
  var message = event.Records[0].Sns.Message;
  console.log(topic + '  ' + message);
  callback(null, { message: 'SNS lamdba was triggered from the topic ' + topic + ' with message ' + message , event });
};

当我改变括号内的值时，我仍然得到相同的错误。有人知道问题出在哪里吗？

Answer 1

使用SNS调用lambda函数时，该函数需要一个具有特定属性的事件对象。因此，“测试”您的lambda函数将失败，除非您配置您的lambda测试事件看起来与SNS event完全相同，例如：

{
  "Records": [
    {
      "EventVersion": "1.0",
      "EventSubscriptionArn": eventsubscriptionarn,
      "EventSource": "aws:sns",
      "Sns": {
        "SignatureVersion": "1",
        "Timestamp": "1970-01-01T00:00:00.000Z",
        "Signature": "EXAMPLE",
        "SigningCertUrl": "EXAMPLE",
        "MessageId": "95df01b4-ee98-5cb9-9903-4c221d41eb5e",
        "Message": "Hello from SNS!",
        "MessageAttributes": {
          "Test": {
            "Type": "String",
            "Value": "TestString"
          },
          "TestBinary": {
            "Type": "Binary",
            "Value": "TestBinary"
          }
        },
        "Type": "Notification",
        "UnsubscribeUrl": "EXAMPLE",
        "TopicArn": topicarn,
        "Subject": "TestInvoke"
      }
    }
  ]
}