Test if $fileName is valid file name. Answers question "How do I check if $fileName is completely valid file name in Windows 10?"
Function Test-FilenameValid {
PARAM( [PARAMETER( Mandatory )]
[String]
$filename
)
# IndexOfAny returns -1 if there is no any characters from argument in the string
$filename.IndexOfAny( [System.IO.Path]::GetInvalidFileNameChars() ) -eq -1
}