silly parameter checking

sillyparameterchecking.ps1

function Send-PSNotification {
    [cmdletbinding()]
    param(
        [Parameter(Mandatory,ValueFromPipeline,Position=0)]
        [object]
        $Body,

        [String]
        $Summary = 'PowerShell Notification',

        [ValidateSet('low', 'normal', 'critical')]
        $Urgency,

        [int]
        $ExpireTime,

        [string[]]
        $Icon = "powershell-logo",

        [string[]]
        $Category,

        [string]
        [ValidateNotNullOrEmpty()]
        $SoundFile
    )  
    $notifySendArgs = switch ($PSBoundParameters.Keys) {
        'Urgency' { "--urgency=$Urgency" }

        'ExpireTime' { "--expire-time=$ExpireTime" }

        'Catagory' { "--category=$($Catagory -join ',')" }

        'SoundFile' { "--hint=string:sound-file:$SoundFile" }

        'Icon' {
            if ($Icon -eq "powershell-logo") {
                Add-DefaultPSIcon
            }
            "--icon=$($Icon -join ',')"
        }
        Default {}
    }
    $notifySendArgs
}