M365DSCUtil: Problem naming similar resources

[ricmestre]

Description of the issue

Cmdlet Get-M365DSCExportContentForResource, from M365DSCUtil.psm1, takes care of giving a ResourceInstanceName to the exported resource, this works out well if all resources have unique names but if they are similar then a "-2" will be appended to the name.

E.g.: I have 4 policies with similar names, as per below, and since Windows 10/11 - Update - Global is processed last then the instance name will be Windows 10/11 - Update - Global-2, this happens because $Global:M365DSCExportedResourceInstancesNames on L3304 is not being declared as a string array and therefore ends up as a regular string with all exported resources which if Contains method is run against will return as true.

Windows 10/11 - Update - Global Wave 1
Windows 10/11 - Update - Global Wave 2
Windows 10/11 - Update - Global Wave 3
Windows 10/11 - Update - Global

The simplest solution for this problem is to just cast $Global:M365DSCExportedResourceInstancesNames as a string array, in fact in Export-M365DSCConfiguration this var is being declared as an array so this matches my observation.

Microsoft 365 DSC Version

DEV

Which workloads are affected

other

The DSC configuration

N/A

Verbose logs showing the problem

Please read description

Environment Information + PowerShell Version

OsName               : Microsoft Windows 10 Enterprise
OsOperatingSystemSKU : EnterpriseEdition
OsArchitecture       : 64-bit
WindowsVersion       : 2009
WindowsBuildLabEx    : 19041.1.amd64fre.vb_release.191206-1406
OsLanguage           : en-US
OsMuiLanguages       : {en-US}

Name                           Value
----                           -----
PSVersion                      5.1.19041.3031
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.19041.3031
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1