Exceptions thrown from Kafka microservice are not sent

[svyatogor]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

When you throw an exception from Kafka based micro service message handler it seems that it is supposed to be places in kafka_nest-err message header by assignErrorHeader. However BaseRpcExceptionFilter returns an object that cannot be fed into Buffer.from so we get an error and the exception is never delivered.

nest/packages/microservices/server/server-kafka.ts

Line 231 in 2e3727b

outgoingMessage.headers[KafkaHeaders.NEST_ERR] = Buffer.from(

Error: Ouch!
    at ServerController.getHello (/Users/sergeykuleshov/Projects/nest-ms-kafka-ex/dist/apps/server/main.js:76:15)
    at /Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/@nestjs/microservices/context/rpc-context-creator.js:44:33
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at /Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/@nestjs/microservices/context/rpc-proxy.js:11:32
    at ServerKafka.handleMessage (/Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/@nestjs/microservices/server/server-kafka.js:112:54)
    at Runner.processEachMessage (/Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/kafkajs/src/consumer/runner.js:191:9)
    at onBatch (/Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/kafkajs/src/consumer/runner.js:393:9)
    at /Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/kafkajs/src/consumer/runner.js:409:9
    at /Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/kafkajs/src/consumer/worker.js:29:9
TypeError: The first argument must be of type string or an instance of Buffer, ArrayBuffer, or Array or an Array-like Object. Received an instance of Object
    at new NodeError (node:internal/errors:371:5)
    at Function.from (node:buffer:322:9)
    at ServerKafka.assignErrorHeader (/Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/@nestjs/microservices/server/server-kafka.js:137:73)
    at ServerKafka.sendMessage (/Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/@nestjs/microservices/server/server-kafka.js:119:14)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at /Users/sergeykuleshov/Projects/nest-ms-kafka-ex/node_modules/@nestjs/microservices/server/server.js:47:25

Minimum reproduction code

https://github.com/svyatogor/nest-ms-kafka-ex

Steps to reproduce

1. nest start server
2. nest start client
3. visi http://localhost:3000 to trigger the micro service call

Expected behavior

The message should be serialised before being set onto the header.

Package

• I don't know. Or some 3rd-party package
• @nestjs/common
• @nestjs/core
• @nestjs/microservices
• @nestjs/platform-express
• @nestjs/platform-fastify
• @nestjs/platform-socket.io
• @nestjs/platform-ws
• @nestjs/testing
• @nestjs/websockets
• Other (see below)

Other package

No response

NestJS version

8.4.5

Packages versions

 "@nestjs/common": "^8.0.0",
"@nestjs/core": "^8.0.0",
"@nestjs/microservices": "^8.4.5",
"@nestjs/platform-express": "^8.0.0",
"kafkajs": "^2.0.1",
"reflect-metadata": "^0.1.13",
"rimraf": "^3.0.2",
"rxjs": "^7.2.0"

Node.js version

16.14

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[kamilmysliwiec]

This has been fixed in this PR #9586 and will be published as part of v9.0.0