Author Posts

May 15, 2017 at 11:35 am

Hi,
I'm a newbie to Pester so please forgive me if this has been answered already. I want to run multiple unit tests on a PowerShell function, providing a range of mocks to exercise the function. Below is the function and test code I've written. I'd like to mock Get-WASJob multiple times, providing a separate mock to each unit test.
How do I do this?
Thanks,
John

Function GetWASJob {
    param ( [string]$project, [string]$job, [string]$os, [string]$runtype )
    $runjob = Get-WASJob -ProjectName $project -JobName $job -ErrorAction Stop

    #Check if the WAS job is valid
    if ($runjob -and $runjob.JobName) {
        WriteToLog "GetWASJob: Returned a valid WAS job" $logfile
    }
    else {
        WriteToLog "GetWASJob: Valid WAS job not returned...Quit" $logfile
        break
    }
    return $runjob
}

Pester code to test the above function:

Describe "GetWASJob" {
    Context "Just Testing..." {
        Mock Get-WASJob {
            $obj = New-MockObject -Type 'Microsoft.Assessments.WAS.PowerShell.WASJob'
            $obj | Add-Member -Type NoteProperty -Name 'JobName' -Value 'PesterJob1' -Force
            $obj | Add-Member -Type NoteProperty -Name 'Tags' -Value 'PesterTag1' -Force
            return $obj
        }

    	$result = GetWASJob -project "Project1" -job "Job1" -os "Windows10" -runtype "Production"

	    It "Verified that all mocks were called" {
	        Assert-VerifiableMocks
	    }
	    It "Checks that a valid job object was returned" {
            $result.JobName | Should Be "PesterJob1"
	    }
    }
}

May 15, 2017 at 3:55 pm

Hi John,

You should create multiple mocks with different parameter filters. This will allow you to have your Get-WasJob mocks to return different objects.

Here's an example.

Mock -Verifiable 'Get-WASJob' {
            $obj = New-MockObject -Type 'Microsoft.Assessments.WAS.PowerShell.WASJob'
            $obj | Add-Member -Type NoteProperty -Name 'JobName' -Value 'PesterJob1' -Force
            $obj | Add-Member -Type NoteProperty -Name 'Tags' -Value 'PesterTag1' -Force
            return $obj
        } -ParameterFilter { $Project -eq 'Project1' -and $Job -eq 'Job1' -and $Os -eq 'Windows10 -and $RunType -eq 'Production' }

Mock -Verifiable 'Get-WASJob' {
            $obj = New-MockObject -Type 'Microsoft.Assessments.WAS.PowerShell.WASJob'
            $obj | Add-Member -Type NoteProperty -Name 'JobName' -Value 'PesterJob2' -Force
            $obj | Add-Member -Type NoteProperty -Name 'Tags' -Value 'PesterTag2' -Force
            return $obj
        } -ParameterFilter { $Project -eq 'Project2' -and $Job -eq 'Job2' -and $Os -eq 'Windows10 -and $RunType -eq 'Production' }

Once you've got the mocks created and "tagged" as verifiable, you can then run

Assert-VerifiableMocks

to assert that each of them was called. Since you've set a parameter filter on each of the mocks, you can then trust that if all of the mocks were called then that means each of the parameter sets were used on those mocks.