Convert PowerShell Objects to Markdown Display by screen-scraping Format-Table

ConvertTo-Markdown.ps1

using namespace System.Collections.Generic
using namespace Microsoft.PowerShell.Commands.Internal.Format

#Inspired by: https://gist.github.com/aaroncalderon/09a2833831c0f3a3bb57fe2224963942
<#
  .Synopsis
  Converts PowerShell Objects or Format-Table output to Markdown
#>
Function ConvertTo-Markdown {
  [CmdletBinding()]
  [OutputType([string])]
  Param (
    [Parameter(Mandatory, ValueFromPipeline)][PSObject[]]$inputObject
  )
  begin {
    $inputObjects = [List[object]]::new()
  }
  process {
    $inputObjects.Add($inputObject)
  }
  end {
    if ($inputObjects[0].GetType().Name -ne 'FormatStartData') {
      $inputObjects = $inputObjects | Format-Table -AutoSize -GroupBy "$(New-Guid)" # This effectively filters any grouping
    }
    if ($inputObjects.GetType().Name -contains 'GroupStartData') {
      throw [NotSupportedException]'Grouped Tables are not supported'
    }

    [string[]]$stringify = ($inputObjects | Out-String).split([Environment]::NewLine) | Where-Object length

    #We use the dash line because the line above might have spaces in property names
    $headerDashLine = $stringify[1]
    [int[]]$headerIndexes = ($headerDashLine | Select-String -Pattern '-+' -AllMatches).Matches.Index

    $line = 0
    foreach ($currentLine in $stringify) {
      # Insert | into the string at the header indexes
      $i = 0
      foreach ($index in $headerIndexes) {
        $currentLine = $currentLine.Insert(($index + $i), '|')
        $i++
      }
      $line++
      "$currentLine|" + [Environment]::NewLine
      continue
    }

  }
}