Investigate issue with Azure Functions integration when promises are returned

[hectorhdzg]

Related to Azure/azure-functions-nodejs-worker#652 (comment)

[paulsmithkc]

Can we get some more clarity on what this issue is, and what the available workarounds are?

This bug took down a business critical system today.

[chuanqisun]

(originally posted in Azure/azure-functions-nodejs-worker#652)

+1 This is blocking us from upgrading to 2.4, which contains important security fixes from #1057

In our case, calling appInsights.setup() would cause Azure Function runtime to throw the error Choose either to return a promise or call 'done'. Do not use both in your script. So maybe investigate the call graph of setup()?

We are using node 16 LTS but I believe the underlying issue is the same. I hope this information helps. If you want repro, feel free to contact me via Microsoft teams DM

ENV
Core Tools Version:       4.0.4895 Commit hash: N/A  (64-bit)
Function Runtime Version: 4.13.0.19486
Node:                     v16.19.0