Uninstall-OutdatedModules.ps1

Uninstall-OutdatedModules.ps1

[CmdletBinding(SupportsShouldProcess = $True)]
Param(
	[Parameter(Mandatory, Position = 1)]
	[string]$ModuleName,
	[Parameter(Position = 2)]
	[bool]$DeleteChildModules = $true
)

$Latest = Get-InstalledModule $ModuleName -ErrorAction Ignore;

# If this module is installed at all
if ($Latest) {
	Write-Verbose "Latest installed version of '$ModuleName' is $($Latest.Version)"

	# Create an array of module names to check
	[array]$AllModules = @($Latest)

	if ($DeleteChildModules) {
		# Add a wildcard at the end
		$WildcardModuleName = "$ModuleName$(if ($DeleteChildModules) { '.*' })"
		# Retrieve all modules that start with the module name, add them to the array
		$AllModules += Get-InstalledModule $WildcardModuleName -ErrorAction SilentlyContinue

		Write-Verbose "Found $($AllModules.Length - 1) child modules to check"
	}

	# Loop through all modules (parent + children)
	foreach ($CurrentModule in $AllModules) {
		$Latest = Get-InstalledModule $CurrentModule.Name
			
		$ModulesToRemove = Get-InstalledModule $CurrentModule.Name -AllVersions | `
			Where-Object { $_.Version -ne $Latest.Version } 
			
		Write-Verbose "Found $($ModulesToRemove.Length) old versions of '$($CurrentModule.Name)'"

		foreach ($ModuleToRemove in $ModulesToRemove) {
			Write-Host "Uninstalling version '$($ModuleToRemove.Version)' of '$($ModuleToRemove.Name)'"
			Uninstall-Module -InputObject $ModuleToRemove -WhatIf:$WhatIfPreference -Force
		}
	}
}
else {
	Write-Warning "No installed version of $ModuleName found"
}

Significant update that's better at handling parent/child modules.

Usage example:

.\Uninstall-OutdatedModules.ps1 Az -Verbose -WhatIf