Mocking with Pester

MockPester.ps1

Remove-Module 'Smlets'
Import-Module 'C:\Program Files\Common Files\SMLets\SMLets.psd1' -Force

$here = Split-Path -Parent $MyInvocation.MyCommand.Path
Import-Module (Join-Path $here "ScsmBulkOperations.psd1") -Force

Describe "Move-ScsmObject" {
	$Session = New-ScsmMigrationSession -SourceComputerName 'SourceComp' -TargetComputerName 'TargetComp'

	Context "When classes differ between source and target SCSM (number of properties) and strict specified" {

		Mock Get-ScsmClass -ModuleName 'ScsmBulkOperations' -MockWith { @{ PropertyCollection = @() }}

		Mock Get-ScsmClass -ModuleName 'ScsmBulkOperations' -ParameterFilter { $ComputerName -eq 'SourceComp' -and $ClassName -eq 'TestClass' } -MockWith { @{
			PropertyCollection = 1..5
		} }
		
		Mock Get-ScsmClass -ModuleName 'ScsmBulkOperations' -ParameterFilter { $ComputerName -eq 'TargetComp' -and $ClassName -eq 'TestClass' } -MockWith { @{
			PropertyCollection = 1..6
		} } 

		It "Should throw an error" {
			{ Move-ScsmObject -ClassName 'TestClass' -Session $Session -Strict } | Should throw "Source and target property sets do not match."
		}
	}
}

#
# [-] Should throw an error 2.37s
#      Expected: the expression to throw an exception with message {Source and target property sets do not match.}, an exception was raised, message was {No such host is known}
#