The revealAzureResource API, when used to reveal a resource group, does nothing if the grouping isn't by resource group

[bwateratmsft]

In the AZD extension we have a command to reveal the Azure resource group that is associated with a particular deployed environment. We use the Azure Resources extensions API to do this, in particular api.resources.revealAzureResource(). However, when revealing resource groups, nothing happens if the resources view isn't grouped by resource group. Ideally, we would at least warn and provide an option to switch.

Discovered from Azure/azure-dev#4532