TypeError: Cannot read properties of undefined (reading 'send')

[ryanbecker]

• Package Name: @azure/service-bus
• Package Version: 7.9.2
• Operating system: Windows (Azure App Services)
• nodejs
  • version: 18
• browser
  • name/version:
• typescript
  • version:
• Is the bug related to documentation in
  • README.md
  • source code documentation
  • SDK API docs on https://docs.microsoft.com

Describe the bug
Sometimes the underlying sender link is undefined when calling sender.sendMessages and our error handling and retry logic is invoked due to failure to send during the first attempt. Here's the error thrown and relevant call stack:

TypeError: Cannot read properties of undefined (reading 'send')
at Object.sendEventPromise [as operation] (C:\home\site\wwwroot\node_modules\@azure\service-bus\dist\index.js:9099:50)
at processTicksAndRejections (node:internal/process/task_queues:96:5)
at async Object.retry (C:\home\site\wwwroot\node_modules\@azure\core-amqp\dist\index.js:1445:22)
at async MessageSender.send (C:\home\site\wwwroot\node_modules\@azure\service-bus\dist\index.js:9174:20)
at async Object.withSpan (C:\home\site\wwwroot\node_modules\@azure\core-tracing\dist\index.js:140:28)

We are sending internal @azure/service-bus logs to App Insights and we usually see the sender_closed and session_closed events around the same time.

The call stack points to this line of code, where the sender link is assumed to have a value:

azure-sdk-for-js/sdk/servicebus/service-bus/src/core/messageSender.ts

Line 230 in f0ff24f

const delivery = await this.link!.send(encodedMessage, {

To Reproduce
Steps to reproduce the behavior:

1. Maybe use Service Bus Standard to increase the changes of lost connectivity? Probably a unit test could neatly reproduce this race condition.
2. Send a message while the underlying sender link is being recreated and is undefined.

Expected behavior

1. No TypeErrors, even in the context of poor connectivity to the Service Bus servers.
2. Automatic retry within the Service Bus library if the session/sender/anything else is being recreated. This is how the library has always worked and seems to be the intent - this is all happening inside the _trySend function and the whole send operation is wrapped in coreAmqp.retry.

Screenshots
If applicable, add screenshots to help explain your problem.

Additional context
Add any other context about the problem here.

[jeremymeng]

@ryanbecker Thanks for the report! I will look into it.

[jeremymeng]

PR #27557

[jeremymeng]

fixed