Public/Serverless/Property Types/Add-SAMSNSEventSource.ps1

function Add-SAMSNSEventSource {
    <#
    .SYNOPSIS
        Adds a SNS Event Source to a Serverless Application Model resource

    .DESCRIPTION
        The object describing an event source with type SNS.

    .LINK
        https://github.com/awslabs/serverless-application-model/blob/master/versions/2016-10-31.md#sns

    .PARAMETER LogicalId
        The logical ID must be alphanumeric (A-Za-z0-9) and unique within the template. Use the logical name to reference the resource in other parts of the template.

    .PARAMETER Topic
        Topic ARN.

    .FUNCTIONALITY
        Serverless
    #>

    [OutputType('Vaporshell.Serverless.EventSource.SNS')]
    [cmdletbinding()]
    Param
    (
        [parameter(Mandatory = $true,Position = 0)]
        [ValidateScript( {
                if ($_ -match "^[a-zA-Z0-9]*$") {
                    $true
                }
                else {
                    throw 'The logical ID must be alphanumeric (a-z, A-Z, 0-9) and unique within the template.'
                }
            })]
        [System.String]
        $LogicalId,
        [parameter(Mandatory = $true)]
        [ValidateScript( {
                $allowedTypes = "System.String","Vaporshell.Function"
                if ([string]$($_.PSTypeNames) -match "($(($allowedTypes|ForEach-Object{[RegEx]::Escape($_)}) -join '|'))") {
                    $true
                }
                else {
                    throw "This parameter only accepts the following types: $($allowedTypes -join ", "). The current types of the value are: $($_.PSTypeNames -join ", ")."
                }
            })]
        $Topic
    )
    $Params = @{
        LogicalId = $LogicalId
        Type = "SNS"
        Properties = @{
            Topic = $Topic
        }
    }
    Add-SAMEventSource @Params | Add-ObjectDetail -TypeName 'Vaporshell.Serverless.EventSource.SNS'
}