Join-Object

Join-Object.ps1

function Join-Object {
    <#
    .SYNOPSIS
    Join properties of two objects into one.
    
    .DESCRIPTION
    Compare properties from two objects and join them into one.
    
    If properties exist in both objects and their values are not equal, reference values will be replaced.
    Properties which only exist in the difference object will be added to the reference object.

    Important: Objects must have the same type. Arrays and hashtables cannot be joined.

    .PARAMETER ReferenceObject
    Object to update.
    
    .PARAMETER DifferenceObject
    Object containing new properties and values to add.
    
    .EXAMPLE
    Join-Object -ReferenceObject $Object1 -DifferenceObject $Object2
    #>
    
    param(
        [Parameter(Mandatory = $true)]
        [system.object]$ReferenceObject,

        [Parameter(Mandatory = $true)]
        [system.object]$DifferenceObject
    )

    $ReferenceKeys = ($ReferenceObject | Get-Member -MemberType NoteProperty).Name
    $DifferenceKeys = ($DifferenceObject | Get-Member -MemberType NoteProperty).Name

    # Working with hashtables?
    $HashTable = [bool]('Hashtable' -in ($ReferenceObject.GetType().Name, $DifferenceObject.GetType().Name))

    # Gather differently for hashes
    if ($HashTable) {
        $ReferenceKeys = $ReferenceObject.Keys
        $DifferenceKeys = $DifferenceObject.Keys
    }

    foreach ($Property in $DifferenceKeys) {
        # Add missing property to reference object
        if ($Property -notin $ReferenceKeys -and $Hashtable.IsPresent -eq $true) {
            $ReferenceObject.Add($Property, 'null')
        }
        elseif ($Property -notin $ReferenceKeys -and $Hashtable.IsPresent -eq $false) {
            $ReferenceObject | Add-Member -MemberType NoteProperty -Name $Property -Value $null
        }

        # Set new value
        if ($DifferenceObject.$Property -ne $ReferenceObject.$Property) {
            $ReferenceObject.$Property = $DifferenceObject.$Property
        }
    }

    return $ReferenceObject
}