functions/Watch-DbaUpdate.ps1

function Watch-DbaUpdate {
    <#
    .SYNOPSIS
        Just for fun - checks the PowerShell Gallery every 1 hour for updates to dbatools. Notifies once per release.
 
    .DESCRIPTION
        Just for fun - checks the PowerShell Gallery every 1 hour for updates to dbatools. Notifies once max per release.
 
        Anyone know how to make it clickable so that it opens an URL?
 
    .NOTES
        Tags: JustForFun, Module
        Author: Chrissy LeMaire (@cl), netnerds.net
 
        Website: https://dbatools.io
        Copyright: (c) 2018 by dbatools, licensed under MIT
        License: MIT https://opensource.org/licenses/MIT
 
    .LINK
        https://dbatools.io/Watch-DbaUpdate
 
    .EXAMPLE
        PS C:\> Watch-DbaUpdate
 
        Watches the gallery for updates to dbatools.
 
#>

    [cmdletbinding()]
    param()
    process {
        if (([Environment]::OSVersion).Version.Major -lt 10) {
            Write-Message -Level Warning -Message "This command only supports Windows 10 and higher."
            return
        }

        if ($null -eq (Get-ScheduledTask -TaskName "dbatools version check" -ErrorAction SilentlyContinue)) {
            Install-DbaWatchUpdate
        }

        # leave this in for the scheduled task
        $module = Get-Module -Name dbatools

        if (-not $module) {
            Import-Module dbatools
            $module = Get-Module -Name dbatools
        }

        $galleryVersion = (Find-Module -Name dbatools -Repository PSGallery).Version
        $localVersion = $module.Version

        if ($galleryVersion -le $localVersion) { return }

        $file = "$env:LOCALAPPDATA\dbatools\watchupdate.xml"

        $new = [PSCustomObject]@{
            NotifyVersion = $galleryVersion
        }

        # now that notifications stay until they are checked, we just have to keep
        # track of the last version we notified about

        if (Test-Path $file) {
            $old = Import-Clixml -Path $file -ErrorAction SilentlyContinue

            if ($galleryVersion -gt $old.NotifyVersion) {
                Export-Clixml -InputObject $new -Path $file
                Show-Notification -GalleryVersion $galleryVersion
            }
        } else {
            $directory = Split-Path $file

            if (!(Test-Path $directory)) {
                $null = New-Item -ItemType Directory -Path $directory
            }

            Export-Clixml -InputObject $new -Path $file
            Show-Notification -GalleryVersion $galleryVersion
        }
    }
}