ResponseError provides root_cause of an exception

[mshustov]

🚀 Feature Proposal

To refactor ResponseError.toString method format to include root_cause details provided by Elasticsearch server.

Motivation

Applications often log a caught exceptions without additional effort for serialization.
If you log ResponseError

try {
  await client.search(...);
} catch (e) {
  console.error(e)
}

you don't get an original error_cause:

    ResponseError: illegal_argument_exception
        at onBody (.../node_modules/@elastic/elasticsearch/lib/Transport.js:337:23)
        at IncomingMessage.onEnd (.../node_modules/@elastic/elasticsearch/lib/Transport.js:264:11)
        at IncomingMessage.emit (events.js:327:22)
        at endReadableNT (internal/streams/readable.js:1327:12)
        at processTicksAndRejections (internal/process/task_queues.js:80:21) {
      meta: {
        body: { error: [Object], status: 400 },
        statusCode: 400,
        headers: {
          'content-type': 'application/json;charset=utf-8',
          'content-length': '367'
        },
        meta: {
          context: null,
          request: [Object],
          name: 'elasticsearch-js',
          connection: [Object],
          attempts: 0,
          aborted: false
        }
      }
    }

that makes debugging quite painful.

To makeerror.message actionalbe, it should include the root_cause provided by Elasticsearch server: ResponseError: [illegal_argument_exception]. caused by [{ type: "...", reason: "..." }]