如何区分删除更新在cosmosdb中创建触发器到azure函数

我在azure中的cosmosdb to azure函数上创建了一个触发器,我在文档中找不到如何区分删除、更新和创建的任何内容

{
  "bindings": [
    {
      "type": "cosmosDBTrigger",
      "name": "input",
      "direction": "in",
      "leaseCollectionName": "leases",
      "connectionStringSetting": "pcmDevValidAppsTrigger_ConnectionString",
      "databaseName": "pcmobile-dev",
      "collectionName": "validApps",
      "createLeaseCollectionIfNotExists": true
    }
  ]
}

module.exports = async (context, documents) => {
    context.log('Document Id: ', documents[0].id);
}