我正在尝试从vtl appsync解析程序对elasticsearch索引执行批量操作。
特别是这种突变：

input CreateTopicsInput {
  language: String!
  texts: [String!]!
}
type Mutation {
  createTopics(input: CreateTopicsInput!): [Topic!]
}

我创建了以下解析器：mutation.createtopics.req.vtl

# set( $body = "" )
# set( $q = '"' )
# foreach( $text in $ctx.args.input.texts )
  #set( $body = $body.concat("{ ${q}index${q}: { ${q}_id${q}: ${q}${text}${q} } }
") )
  #set( $body = $body.concat("{ ${q}text${q}: ${q}$text${q}, ${q}suggest${q}: { ${q}input${q}: ${q}$text${q} } }
") )
# end
{
  "version": "2017-02-28",
  "operation": "POST",
  "path": "/topic-${ctx.args.input.language}/doc/_bulk",
  "params": {
    "headers" : [ { "Content-Type" : "application/x-ndjson" } ],
    "body": "$body"
  }
}

例如，当用这个数据执行时：

mutation CreateTopic {
  createTopics(input: {
    language: "en",
    texts: [ "COVID", "Election" ]}) {
    text
  }
}

似乎输出了正确的调用：

{
  "version": "2017-02-28",
  "operation": "POST",
  "path": "/topic-en/doc/_bulk",
  "params": {
    "headers" : [ { "Content-Type" : "application/x-ndjson" } ],
    "body": "{ "index": { "_id": "COVID" }
{ "text": "COVID" }
{ "index": { "_id": "Election" }
{ "text": "Election" }
"
  }
}

但它不起作用。特别是它抛出：

{
  "data": {
    "createTopics": null
  },
  "errors": [
    {
      "path": [
        "createTopics"
      ],
      "data": null,
      "errorType": "MappingTemplate",
      "errorInfo": null,
      "locations": [
        {
          "line": 2,
          "column": 3,
          "sourceName": null
        }
      ],
      "message": "Unexpected character ('i' (code 105)): was expecting comma to separate Object entries\n at [Source: (String)\"{\n  \"version\": \"2017-02-28\",\n  \"operation\": \"POST\",\n  \"path\": \"/topic-en/doc/_bulk\",\n  \"params\": {\n    \"headers\" : { \"Content-Type\" : \"application/x-ndjson\" },\n    \"body\": \"{ \"index\": { \"_id\": \"CODID\" } }\n{ \"text\": \"CODID\", \"suggest\": { \"input\": \"CODID\" } }\n{ \"index\": { \"_id\": \"Election\" } }\n{ \"text\": \"Election\", \"suggest\": { \"input\": \"Election\" } }\n\"\n  }\n}\n\"; line: 7, column: 18]"
    }
  ]
}

有什么主意吗？