e = { '$emit': { connectionName: 's3test', 
    bucket: 'jsncluster0datafed', 
    path: { $concat: ["data/", { $meta: "stream.source.ns.db" }, "/", { $meta: "stream.source.ns.coll" }] }, 
    config: { writeOptions: { bytes: 16777216, interval: { size: 5, unit: 'second' } },
     delimiter: '\n', outputFormat: 'basicJson', dateFormat: 'ISO8601' } } }


{
  _dlqMessage: {
    _stream_meta: {
      source: {
        type: 'atlas',
        ts: ISODate('2025-09-03T13:15:14.256Z'),
        operationType: 'insert',
        ns: {
          db: 'test',
          coll: 'test'
        },
        documentKey: {
          _id: ObjectId('68b83f6230aa6a85816e8d10')
        }
      }
    },
    errInfo: {
      reason: 'Failed to evaluate $emit.bucket or $emit.path for S3 sink :: caused by :: Expected string, but got null'
    },
    operatorName: 'S3EmitOperator',
    doc: {
      _id: ObjectId('68b83f6230aa6a85816e8d10'),
      test: 1
    },
    processorName: 'internal-anon-stream-processor-68b83f60d48d19195b5878c9',
    dlqTime: ISODate('2025-09-03T13:15:16.806Z')
  }
}