functions/Get-DbaRepPublication.ps1

function Get-DbaRepPublication {
    <#
        .SYNOPSIS
            Displays all publications for a server or database.
 
        .DESCRIPTION
            Quickly find all transactional, merge, and snapshot publications on a specific server or database.
 
        .PARAMETER SqlInstance
            Allows you to specify a comma separated list of servers to query.
 
        .PARAMETER Database
            The database(s) to process. If unspecified, all databases will be processed.
 
        .PARAMETER SqlCredential
            Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
 
        .PARAMETER PublicationType
            Limit by specific type of publication. Valid choices include: Transactional, Merge, Snapshot
 
        .PARAMETER EnableException
        byng this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
 
        .NOTES
            Author: Colin Douglas
            Tags: Replication
 
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: MIT https://opensource.org/licenses/MIT
 
        .LINK
            https://dbatools.io/Get-DbaRepPublication
 
        .EXAMPLE
            PS C:\> Get-DbaRepPublication -SqlInstance sql2008, sqlserver2012
 
            Return all publications for servers sql2008 and sqlserver2012.
 
        .EXAMPLE
            PS C:\> Get-DbaRepPublication -SqlInstance sql2008 -Database TestDB
 
            Return all publications on server sql2008 for only the TestDB database
 
        .EXAMPLE
            PS C:\> Get-DbaRepPublication -SqlInstance sql2008 -PublicationType Transactional
 
            Return all publications on server sql2008 for all databases that have Transactional publications
#>

    [CmdletBinding()]
    param (
        [parameter(Mandatory, ValueFromPipeline)]
        [DbaInstanceParameter[]]$SqlInstance,
        [object[]]$Database,
        [PSCredential]$SqlCredential,
        [ValidateSet("Transactional", "Merge", "Snapshot")]
        [object[]]$PublicationType,
        [switch]$EnableException
    )

    process {

        foreach ($instance in $SqlInstance) {

            # Connect to Publisher
            try {
                Write-Message -Level Verbose -Message "Connecting to $instance"
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential -MinimumVersion 9
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }

            $dbList = $server.Databases

            if ($Database) {
                $dbList = $dbList | Where-Object name -in $Database
            }

            $dbList = $dbList | Where-Object { ($_.ID -gt 4) -and ($_.status -ne "Offline") }


            foreach ($db in $dbList) {

                if (($db.ReplicationOptions -ne "Published") -and ($db.ReplicationOptions -ne "MergePublished")) {
                    Write-Message -Level Verbose -Message "Skipping $($db.name). Database is not published."
                }

                $repDB = Connect-ReplicationDB -Server $server -Database $db

                $pubTypes = $repDB.TransPublications + $repDB.MergePublications

                if ($PublicationType) {
                    $pubTypes = $pubTypes | Where-Object Type -in $PublicationType
                }

                foreach ($pub in $pubTypes) {

                    [PSCustomObject]@{
                        ComputerName = $server.ComputerName
                        InstanceName = $server.InstanceName
                        SqlInstance  = $server.SqlInstance
                        Server = $server.name
                        Database = $db.name
                        PublicationName = $pub.Name
                        PublicationType = $pub.Type
                    }
                }
            }
        }
    }
}