More fun with PowerShell string expansion for .NET app/web.config

ApplyConfig.ps1

<#
Usage: 
    ApplyConfig "app.config" "DEV"
    
    
    $configFile - the app/web.config we are 'transforming'.  
    $environment - the environment context we are transforming for.  Maybe snarf this from <appSettings><add key="Environment" value="some value"/>?
#>
param($configFile, $environment="LOCAL")

$workingDirectory = Split-Path $MyInvocation.MyCommand.Path

# dot sourcing our variable declarations
#
. .\$($environment).tokens.ps1

$configFilePath = join-path $workingDirectory $configFile -resolve

$content = [IO.File]::ReadAllText($configFilePath)

#content contains all of our configuration, with variable expressions
#calling ExpandString will replace those expressions with their values
#
$expandedConfig = $ExecutionContext.InvokeCommand.ExpandString($content)


# uncomment to see values
# $expandedConfig
#set-content with $expandedConfig in output folder

DEV.tokens.ps1

$MyDbConnection="my DEV connection string"
$HostMachineName = "DEV001"

LOCAL.tokens.ps1

$MyDbConnection="my local connection string"
$HostMachineName = [environment]::machinename