[BUG] ClientContext.IsAppOnly() might fail when authenticated with ClientCredentials

[koskila]

Reporting an Issue or Missing Feature

There's an issue when you add ClientContext.IsAppOnly() and are using ClientCredentials. It seems to randomly throw an uncaught 403 and crash.

Expected behavior

When calling .IsAppOnly() it should return true or false, not throw (at least not if it is able to fetch the Access Token!)

Actual behavior

When debugging it, I noticed it doesn't happen on first execution of the handler for extracting the AccessToken, but rather on one of the subsequent ones. It's not even actually executing a real query (it's a dummy) but that still fails somehow.

Steps to reproduce behavior

1. Connect-PnPOnline with ClientCredentials
2. Call ClientContext.IsAppOnly() in the commandlet's code
3. Observe

What is the version of the Cmdlet module you are running?

Latest dev (f3b8aeffdccc168355d8335ef17d884fd20235b1)

Which operating system/environment are you running PnP PowerShell on?

• Windows
• Linux
• MacOS
• Azure Cloud Shell
• Azure Functions
• Other : please specify

Next steps

I'll have a fix proposed in a minute.