Powershell - How to script a session refresh in powershell? - powershell

Question

I have one ps1 script that drives the operations I want to perform.
I am using modules with class definitions in the modules that use Command pattern.
All is well and good first time I open a powershell session console and run the script.
If I change a class in any way and re-run in the same console, the console does not seem to be picking up the changed script. I have to close the powershell console and run the script fresh in order for my changes work. Otherwise I just get the script behaving the same way it does before I made the change. Clearly there is some caching going on.
I am wondering if MS has finally resolved this issue. I have read many older posts with complaints about this.
I have tried the following and none of them appears to work:
Remove-Variable * -ErrorAction SilentlyContinue;
Remove-Module *;
$error.Clear();
Clear-Host
I have even tried all of them together. Still not helping.
Is there something else can can be done to ensure the latest code in any supporting modules gets loaded? Having to close the whole console and reload is a serious productivity issue.
Example of what I am doing:6
using module .\Logger.psm1
using module .\AzurePlatformParmsDefault.psm1
using module .\AzurePlatform.psm1
[Logger] $Logger = [Logger]::Create()
[AzurePlatformParms] $AzurePlatformParms = [AzurePlatformParmsDefault]::Create( $Logger )
[AzurePlatform] $AzurePlatform = [AzurePlatform]::Create( $Logger, $AzurePlatformParms )
[bool] $Result = $AzurePlatform.Execute()

Answer 1

The conventional wisdom is that there isn't a way to do this natively, and creating a new runspace or process is the solution.
You can reset variables to default values and import environment variables from the user/machine scope (on windows); before clearing any jobs, events, event subscribers etc. This isn't a true session refresh though, and classes/custom types will persist.
To speed up your workflow, you may want to use a function in your $profile that can automate creating a new session, and loading in what's needed. This approach can save enough time that it is trivial to recycle an interactive session. I will include the one I use in my profile as an example. It's fairly comprehensive, but I suggest tailoring one that is suitable for your specific needs.
Example
function Start-NewSession {
[CmdletBinding(DefaultParameterSetName = 'NoChange')]
[Alias('sans')]
param(
[Alias('N')]
[switch]
$NoClose,
[Parameter(ParameterSetName = 'Elevate')]
[Parameter(ParameterSetName = 'NoChange')]
[Alias('nop')]
[switch]
$NoProfile,
[Parameter(ParameterSetName = 'Elevate')]
[Parameter(ParameterSetName = 'NoChange')]
[Alias('A')]
[switch]
$AddCommands,
[Parameter(ParameterSetName = 'Elevate')]
[Alias('E')]
[switch]
$Elevate,
[Parameter(ParameterSetName = 'DeElevate')]
[Alias('D')]
[switch]
$DeElevate
)
$PSAppPath = (Get-Process -Id $PID).Path
$SPParams = #{
Filepath = $PSAppPath
WorkingDirectory = $PWD
ArgumentList = ''
}
if ($Elevate.IsPresent) {
$SPParams['Verb'] = 'RunAs'
}
elseif ($DeElevate.IsPresent) {
$SPParams['FilePath'] = Join-Path $env:windir 'explorer.exe'
$SPParams['ArgumentList'] = $PSAppPath
}
if ($NoProfile.IsPresent) {
$SPParams['ArgumentList'] += ' -NoProfile'
}
if ($AddCommands.IsPresent) {
$ExtraCmds = Read-Host -Prompt 'Post-startup commands'
if (-not [string]::IsNullOrWhiteSpace($ExtraCmds)) {
$SPParams['ArgumentList'] +=
' -NoExit -Command "' + $ExtraCmds.Replace('"', '\"') + '"'
}
}
if ([string]::IsNullOrWhiteSpace($SPParams['ArgumentList'])) {
$SPParams.Remove('ArgumentList')
}
Start-Process #SPParams
if (-not $NoClose.IsPresent) { exit }
}
This permits typing sans to generate a new session and close the old one.