Powershell script to group consecutive numbers

Group-ConsecutiveNumbers.ps1

function Group-ConsecutiveNumbers {
  [CmdletBinding()]
  param(
    [Parameter(ValueFromPipeline, Mandatory, Position=0)]
    $number
  )
  
  begin { $numbers = @() }
  process { $numbers += $number }
  end {
    return $numbers |
      Select-Object -Unique |
      Sort-Object |
      ForEach-Object { $g = @() } { if ($g[-1].e -eq ($_ - 1)) { $g[-1].e = $_ } else { $g += @{b=$_;e=$_} } } { $g } |
      ForEach-Object { if ($_.b -eq $_.e) { $_.b } else { "$($_.b)..$($_.e)" } }
  }
}

# Import:
# Invoke-Expression (iwr "https://gist.githubusercontent.com/elonmallin/8a5e0dfc05d26c2c73a3eb9fda0bfd04/raw/Group-ConsecutiveNumbers.ps1").Content

# Use:
# 1..10 + 12 + 12 + 12 + 14 + 15 + 20..50 + 40 + 80 | Group-ConsecutiveNumbers

# Output:
# 1..10
# 12
# 14..15
# 20..50
# 80