Infrastructure validation script using the Arrange Act Assert principle for creating users from a CSV file

New-ADUsersFromCSV.ps1

<#

      Author: I.C.A. Strachan
      Version:
      Version History:

      Purpose: Infrastructure validation script to create ADUser from CSV file

#>

[CmdletBinding(SupportsShouldProcess=$True)]

Param(
   [string]
   $File = 'C:\scripts\source\csv\users.csv'
)

function ConvertTo-HashTable{
   param(
      [PSObject]$PSObject
   )
   $splat = @{}

   $PSObject | 
   Get-Member -MemberType *Property |
   ForEach-Object{
         $splat.$($_.Name) = $PSObject.$($_.Name)
   }

   $splat
}

Function Create-TestCases{
   param(
      $objActual,
      $objExpected,
      $Properties
   )

   $Properties |
   ForEach-Object{
      @{
         Actual   = $objActual.$_
         Expected = $objExpected.$_
         Property = $_
      }
   }
}

$csvFile =  Get-childItem $file

#region Arrange
#Define proper dependencies
#1) Verify csv file exist
#2) Can user read AD properties.


$dependencies = @(
   @{
      Label  = 'ActiveDirectory module is available '
      Test   = {(Get-module -ListAvailable).Name -contains 'ActiveDirectory'}
      Action = {Import-Module -Name ActiveDirectory}
   }

   @{
      Label  = "CSV File at $($csvFile) exists"
      Test   = {Test-Path -Path $csvFile}
      Action = {
         $script:csvUsers = Import-Csv -Path $csvFile -Delimiter ";" -Encoding UTF8
         $csvColumns = ($csvUsers | Get-Member | Where-Object {$_.membertype -eq 'noteproperty'}).name
         $script:UserProperties = $csvColumns.Where{$_ -ne 'Path'}
      }
   }

   @{
      Label  = "$(& "$env:windir\system32\whoami.exe") can read AD user object properties"
      Test   = {[bool](Get-AdUser -Identity $("$((Get-ADDomain).DomainSID)-500"))}
      Action = {}
   }
)

foreach($dependency in $dependencies){
   if(!( & $dependency.Test)){
      throw "The check: $($dependency.Label) failed. Halting script"
   }
   else{
      Write-Verbose $dependency.Label 
      & $dependency.Action
   }
}
#endregion

$csvUsers |
Foreach-Object{
   $Actual = $_
   Describe "Processing User $($Actual.SamAccountName)"{
      #Convert to HashTable for splatting
      $paramNewADUser = ConvertTo-HashTable -PSObject $Actual

      #region Act
      #1) Create ADUser from csv file

      It "Create an account for $($Actual.SamAccountName)"{
         New-ADUser @paramNewADUser
      }
      #endregion

      #region Assert
      #1) Verify AD user has been created correctly

      #Get AD user properties
      $Expected = Get-ADUser -Identity $Actual.SamAccountName -Properties $UserProperties

      #Create TestCases for verifying Properties
      $TestCases = Create-TestCases -objActual $Actual -objExpected $Expected -Properties $UserProperties

      It 'Verify that property <property> expected value <expected> actually is <actual>' -TestCases $TestCases   {
         param($Actual,$Expected,$Property)
         $Actual.$Property  | should be $Expected.$Property
      }
      #endregion
   }
}

Trying my hand at arrange-act-assert with dependencies included...

Got the dependencies tip from the Pester book by Don Jones & Adam Bertram

I'm using Pester 4.0 where Describe can be nested.

I was pleasantly surprised by the way Pester handled the error when the user already existed

Feels like I'm overthinking this...

Any tips/ideas on how to make this better?

Rg./Irwin

Line 61 - shouldn't it read Get-Module -List ? Current test will result in $false -> throw unless module is loaded already, so action is not really doing anything....

Yeah, I just noticed that myself...
This works:

(Get-module -ListAvailable).Name -contains 'ActiveDirectory'

Will update it... 👍

Reverted back to a single Describe...

Had a lively discussion on FB.

So this isn't a good example of AAA principal, but is it useful? It gives you feedback as to what's going on, what went right and what didn't...

Any takers on how it should be done right? 😁