Kafka errors in E2E tests

Bug Report

Current behavior

In an E2E test with both the receiver and the caller as separate Nest applications started in the same test context, after closing both applications Jest reports an error about trying to import a file after the Jest environment has been torn down.

Jest did not exit one second after the test run has completed.

This usually means that there are asynchronous operations that weren't stopped in your tests. Consider running Jest with `--detectOpenHandles` to troubleshoot this issue.

ReferenceError: You are trying to `import` a file after the Jest environment has been torn down.

      at 1 (../node_modules/kafkajs/src/protocol/requests/heartbeat/index.js:11:21)
      at Broker.heartbeat (../node_modules/kafkajs/src/broker/index.js:314:39)
      at ConsumerGroup.heartbeat (../node_modules/kafkajs/src/consumer/consumerGroup.js:310:30)
      at Runner.fetch (../node_modules/kafkajs/src/consumer/runner.js:317:30)

Input Code

Here’s a link to a minimum reproduction

Expected behavior

Be able to close out both applications with no errors? Honestly, not 100% sure if this is a bug or me implementing something incorrectly, but as the Kafka transport is experimental, I figured it should be brought up.

Possible Solution

I wish I knew. Kafka is still pretty strange to me 😅

Environment

▶ nest info

 _   _             _      ___  _____  _____  _     _____
| \ | |           | |    |_  |/  ___|/  __ \| |   |_   _|
|  \| |  ___  ___ | |_     | |\ `--. | /  \/| |     | |
| . ` | / _ \/ __|| __|    | | `--. \| |    | |     | |
| |\  ||  __/\__ \| |_ /\__/ //\__/ /| \__/\| |_____| |_
\_| \_/ \___||___/ \__|\____/ \____/  \____/\_____/\___/


[System Information]
OS Version     : Linux 5.0
NodeJS Version : v13.14.0
YARN Version    : 1.22.4 

[Nest CLI]
Nest CLI Version : 7.1.5 

[Nest Platform Information]
platform-express version : 7.0.0
microservices version    : 7.0.13
common version           : 7.0.0
core version             : 7.0.0

 
For Tooling issues:
- Node version: 13.14.0
- Platform:  Linux Mint 19.3

Others:

Package manager: Yarn
# These two shouldn't /really/ matter, but I thought I'd add them for the full context
IDE: VSCode
Shell: ZSH

[willsoto]

@jmcdo29 @kamilmysliwiec - Fixed via #5422. This was indeed a bug in Nest

[kamilmysliwiec]

After looking into this issue, I believe that it’s not related to NestJS implementation (Kafka transporter class). Perhaps we should consider reporting this issue in the kafkajs repo instead? @jmcdo29