Measure-ScriptCode calculates some metrics about the PowerShell script files and modules it is fed, like number of comments and lines-of-code.

Measure-ScriptCodePS2.ps1

# Measure-ScriptCode.ps1
# Return metrics about the script and module files 
# This is the PowerShell 2 version; AST is NOT used (PowerShell 3 is required for AST)
# Jan 2014
# If this works, Victor Vogelpoel <victor@victorvogelpoel.nl> wrote this.
# If it doesn't, I don't know who wrote this.
#
# Disclaimer
# This script is provided AS IS without warranty of any kind. I disclaim all implied warranties including, without limitation,
# any implied warranties of merchantability or of fitness for a particular purpose. The entire risk arising out of the use or
# performance of the sample scripts and documentation remains with you. In no event shall I be liable for any damages whatsoever
# (including, without limitation, damages for loss of business profits, business interruption, loss of business information,
# or other pecuniary loss) arising out of the use of or inability to use the script or documentation.

#requires -version 2
Set-PSDebug -Strict
Set-StrictMode -Version Latest

function Measure-ScriptCode
{
	[CmdletBinding()]
	param
	(
	  [Parameter(Mandatory=$true, Position=1, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, HelpMessage="One or more PS1 or PSM1 files to calculate code metrics for")]
	  [Alias('PSPath', 'Path')]
	  [string[]]$ScriptFile
	)
	
	begin
	{
		$files 		= 0
		$modules 	= 0
		$manifests 	= 0
	
		$lines 		= 0
		$words 		= 0
		$characters	= 0
		$codeLines 	= 0
		$comments 	= 0
	}

	process
	{
		foreach ($file in $ScriptFile)
		{
			if ($file -like "*.ps1") { $files++ }
			if ($file -like "*.psm1") { $modules++ }
			if ($file -like "*.psd1") { $manifests++ }
			
			$fileContentsArray	= Get-Content -Path $file
			
			if ($fileContentsArray)
			{
				# First, measure basic metrics
				$measurement 		= $fileContentsArray | Measure-Object -Character -IgnoreWhiteSpace -Word -Line
				$lines 			+= $measurement.Lines
				$words 			+= $measurement.Words
				$characters 		+= $measurement.Characters

				# Next, use AST to extract more complex metrics
				$tokenAst 		= [System.Management.Automation.PSParser]::Tokenize($fileContentsArray, [ref]$null)

				# Get the number of comment lines and comments on the end of a code line
				$comments		+= @($tokenAst | where { $_.Type -eq "Comment" } ).Length 
				# Calculate the lines of code: remove comment tokens from the the tokenAst, remove all double newlines and count all the newlines (minus 1)
				$prevTokenIsNewline	= $false
				$codeLines 		+= @($tokenAst | select -ExpandProperty Type |  where { $_ -ne "comment" } | where {
								if ($_ -ne "NewLine" -or (!$prevTokenIsNewline))
								{
									$_
								}
								$prevTokenIsNewline = ($_ -eq "NewLine")
							} | where { $_ -eq "NewLine" }).Length-1
			}
		}
	}

	end
	{
		return [PSCustomObject]@{
			Files 		= $files
			Modules 	= $modules
			Manifests	= $manifests

			CodeLines	= $codeLines
			Comments 	= $comments

			Characters 	= $characters
			Lines 		= $lines
			Words		= $words
		}
	}
}


Measure-ScriptCode -ScriptFile (Join-Path (Split-Path $MyInvocation.MyCommand.Path) "Write-HelloWorld.ps1")