private/Set-PSScriptInfo.ps1

<#PSScriptInfo
{
  "VERSION": "1.0.0.0",
  "GUID": "48011ba6-1489-4f2b-b620-dc1923486418",
  "FILENAME": "Set-PSScriptInfo.ps1",
  "AUTHOR": "Hannes Palmquist",
  "AUTHOREMAIL": "hannes.palmquist@outlook.com",
  "CREATEDDATE": "2019-09-24",
  "COMPANYNAME": "N/A",
  "COPYRIGHT": "© 2019, Hannes Palmquist, All Rights Reserved"
}
PSScriptInfo#>


function Set-PSScriptInfo
{
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSUseShouldProcessForStateChangingFunctions', '', Justification = 'No system state changed')]
    <#
    .DESCRIPTION
        Adds a PSScriptInfo block to a file
    .PARAMETER FilePath
        FilePath for file to set PSScriptInfo for
    .PARAMETER JSON
        String value containing json formatted PSScriptInfo
    .EXAMPLE
        Set-PSScriptInfo -Filepath C:\Script\Get-Test.ps1 -JSON $JSON
    #>


    [CmdletBinding()] # Enabled advanced function support
    param(
        [ValidateScript( { Test-Path $_.FullName -PathType Leaf })]
        [Parameter(Mandatory)]
        [System.IO.FileInfo]
        $FilePath,

        [Parameter(Mandatory)]
        [string]
        $JSON,

        [int]
        $InsertAt = 0
    )

    try
    {
        $null = $JSON | ConvertFrom-Json -ErrorAction Stop
        Write-Verbose 'Tested JSON input for valid JSON'
    }
    catch
    {
        throw 'Failed to parse input JSON, input is not valid JSON'
    }

    # Increase indent from two to four
    $JSON.Replace(' ', ' ')

    $JSON = ("<#PSScriptInfo$([system.environment]::NewLine){0}$([system.environment]::NewLine)PSScriptInfo#>$([system.environment]::NewLine)" -f $JSON)
    Write-Verbose 'Added prefix and suffix to JSON block'

    try
    {
        $FileContent = Get-Content -Path $FilePath -ErrorAction Stop
        Write-Verbose -Message ('Read content from filepath')
    }
    catch
    {
        throw ('Failed to read content from filepath with error: {0}' -f $_.exception.message)
    }

    $StringBuilder = [System.Text.StringBuilder]::new(($FileContent) -join ([system.environment]::NewLine))
    Write-Verbose -Message ('Created stringbuilder')

    $null = $StringBuilder.Insert($InsertAt, ($JSON))
    Write-Verbose -Message ('Inserted PSScriptInfo at beginning of content block')

    try
    {
        $StringBuilder.ToString() | Set-Content -Path $FilePath -Encoding utf8 -ErrorAction Stop
        Write-Verbose -Message ('Successfully wrote content block back to file')
    }
    catch
    {
        throw ('Failed to write content block back to file with error: {0}' -f $_.exception.message)
    }
}
#endregion