function Get-SlackMessage {
<#
.SYNOPSIS
    Create a Slack Message.

.PARAMETER Username
    To specify the username for the published message.

.PARAMETER IconEmoji
    To specify an emoji (using colon shortcodes, eg. :white_check_mark:) to use as the profile photo alongside the message.

.PARAMETER Text
    The main body text of the message.

.PARAMETER Channel
    Channel, private group, or IM channel to send message to.

.PARAMETER Attachments
    One of these arguments is required to describe the content of the message. See the function 'Get-SlackAttachment' for more information.
#>
    [CmdletBinding()]
    [OutputType([object])]
    param (
        [Parameter(Mandatory = $true)]
        [string]$Username,

        [Parameter(Mandatory = $true)]
        [string]$IconEmoji,

        [Parameter(Mandatory = $true)]
        [string]$Text,

        [Parameter(Mandatory = $true)]
        [string]$Channel,

        [Parameter(Mandatory = $false)]
        [object[]]$Attachments = $null
    )

    $IconEmoji = $IconEmoji.replace(':', '')
    $normalizedIconEmoji = ":$($IconEmoji):"

    $message = @{
        username   = $Username
        icon_emoji = $normalizedIconEmoji
        text       = $Text
        channel    = $Channel
    }

    if (![string]::IsNullOrWhiteSpace($Channel)) {
        $message.channel = $Channel
    }

    if ($null -ne $Attachments) {
        $message.attachments = @($Attachments)
    }

    return $message
}