Private/Add-ObjectTypeInfo.ps1

function Add-ObjectTypeInfo {
    <#
    .SYNOPSIS
        Decorate an object with
            - A TypeName
            - New properties
            - Default parameters

    .DESCRIPTION
        Helper function to decorate an object with
            - A TypeName
            - New properties
            - Default parameters

    .PARAMETER InputObject
        Object to decorate. Accepts pipeline input.

    .PARAMETER TypeName
        Typename to insert.
        
        This will show up when you use Get-Member against the resulting object.
        
    .PARAMETER PropertyToAdd
        Add these noteproperties.
        
        Format is a hashtable with Key (Property Name) = Value (Property Value).

        Example to add a One and Date property:

            -PropertyToAdd @{
                One = 1
                Date = (Get-Date)
            }

    .PARAMETER DefaultProperties
        Change the default properties that show up

    .PARAMETER Passthru
        Whether to pass the resulting object on. Defaults to true

    .EXAMPLE
        #
        # Create an object to work with
        $Object = [PSCustomObject]@{
            First = 'Cookie'
            Last = 'Monster'
            Account = 'CMonster'
        }

        #Add a type name and a random property
        Add-ObjectDetail -InputObject $Object -TypeName 'ApplicationX.Account' -PropertyToAdd @{ AnotherProperty = 5 }

            # First Last Account AnotherProperty
            # ----- ---- ------- ---------------
            # Cookie Monster CMonster 5

        #Verify that get-member shows us the right type
        $Object | Get-Member

            # TypeName: ApplicationX.Account ...

    .EXAMPLE
        #
        # Create an object to work with
        $Object = [PSCustomObject]@{
            First = 'Cookie'
            Last = 'Monster'
            Account = 'CMonster'
        }

        #Add a random property, set a default property set so we only see two props by default
        Add-ObjectDetail -InputObject $Object -PropertyToAdd @{ AnotherProperty = 5 } -DefaultProperties Account, AnotherProperty

            # Account AnotherProperty
            # ------- ---------------
            # CMonster 5

        #Verify that the other properties are around
        $Object | Select -Property *

            # First Last Account AnotherProperty
            # ----- ---- ------- ---------------
            # Cookie Monster CMonster 5

    .NOTES
        This breaks the 'do one thing' rule from certain perspectives...
        The goal is to decorate an object all in one shot
   
        This abstraction simplifies decorating an object, with a slight trade-off in performance. For example:

        10,000 objects, add a property and typename:
            Add-ObjectDetail: ~4.6 seconds
            Add-Member + PSObject.TypeNames.Insert: ~3 seconds

        Initial code borrowed from Shay Levy:
        http://blogs.microsoft.co.il/scriptfanatic/2012/04/13/custom-objects-default-display-in-powershell-30/
    #>

    [CmdletBinding()] 
    param(
        [Parameter( Mandatory = $true,
            Position = 0,
            ValueFromPipeline = $true )]

        $InputObject,

        [Parameter( Mandatory = $false,
            Position = 1)]
        [string]$TypeName,

        [Parameter( Mandatory = $false,
            Position = 2)]    
        [System.Collections.Hashtable]$PropertyToAdd,

        [Parameter( Mandatory = $false,
            Position = 3)]
        [ValidateNotNullOrEmpty()]
        [Alias('dp')]
        [System.String[]]$DefaultProperties,

        [boolean]$Passthru = $True
    )
    
    Begin {
        if ($PSBoundParameters.ContainsKey('DefaultProperties')) {
            # define a subset of properties
            $ddps = New-Object System.Management.Automation.PSPropertySet DefaultDisplayPropertySet, $DefaultProperties
            $PSStandardMembers = [System.Management.Automation.PSMemberInfo[]]$ddps
        }
    }
    Process {
        foreach ($Object in $InputObject) {
            switch ($PSBoundParameters.Keys) {
                'PropertyToAdd' {
                    foreach ($Key in $PropertyToAdd.Keys) {
                        #Add some noteproperties. Slightly faster than Add-Member.
                        $Object.PSObject.Properties.Add( ( New-Object PSNoteProperty($Key, $PropertyToAdd[$Key]) ) )  
                    }
                }
                'TypeName' {
                    #Add specified type
                    [void]$Object.PSObject.TypeNames.Insert(0, $TypeName)
                }
                'DefaultProperties' {
                    # Attach default display property set
                    Add-Member -InputObject $Object -MemberType MemberSet -Name PSStandardMembers -Value $PSStandardMembers
                }
            }
            if ($Passthru) {
                $Object
            }
        }
    }
}