function Test-FileEncoding {
    <#
    .SYNOPSIS
        Returns true if the given file is written in a valid encoding

    .DESCRIPTION
        Test the given file against the encoding regex and returns true or false

    .PARAMETER Path
        Relative or full path to an existing file.

    .PARAMETER Encoding
        Optional custom encoding regex string. Default is (utf8|ascii|xml).

    .INPUTS
        [none]

    .OUTPUTS
        [bool]

    .EXAMPLE
        Test-FileEncoding -Path './testfile.txt'

    .NOTES
    #>

    [CmdletBinding()]
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute(
        'PSAvoidUsingInvokeExpression',
        '',
        Justification = 'static input without user manipulation'
    )]
    [OutputType([bool])]

    param (
        [Parameter(Mandatory = $true)]
        [ValidateScript(
            {
                Test-Path -Path $_
            }
        )]
        [string]$Path,

        [Parameter(Mandatory = $false)]
        [string]$Encoding = '(utf8|utf-8|ascii|xml)'
    )

    begin {
    }

    process {
        try {
            Get-Command -Name 'file' -ErrorAction 'Stop' | Out-Null
        }
        catch {
            Write-Error -Message "Could not find command called 'file'!" -ErrorAction 'Stop'
        }
        $Res = Invoke-Expression -Command ("file '{0}' " -f $Path)
        # Remove the file from matching. Use the latest array element if split doesn't work.
        $ParsedResult = ($Res -split ':')[-1]
        Write-Debug -Message ('Encoding: Raw file output {0}' -f $Res)
        Write-Debug -Message ('Parsed match string: {0}' -f $ParsedResult)
        if ($ParsedResult -match $Encoding) {
            Write-Output $true
        }
        else {
            Write-Output $false
        }
    }

    end {
    }
}