Test-MofResourceType Inadvertently Unloads Module

[alx9r]

This invokation of Import-Module in New-ClassResourceObject seems to re-import the module of the class resource on each invokation even if it has already been loaded. It seems to happen once per bound resource, so the bigger the configuration document the slower the creation of the instructions. Some resource modules are large enough that they take seconds to load. The modules should probably remain cached as they are imported, but they don't currently seem to be.

[alx9r]

It looks like this call to Test-MofResourceType can inadvertently invoke Remove-Module each time a new bound resource is created. The apparent offending call site seems to use an unreliable method for detecting whether a module is already loaded. Here is a trace demonstrating the problem from that call site:

The file extensions differ differ so the module described by $DscResourceInfo unloads the module. That is incorrect. A more rigorous method of detecting whether a module corresponding to a DSC resource is loaded should be used.