备份和还原用户环境变量

上次写了个脚本, 只备份path, 现在不够用了.
我使用scoop安装软件, 装的软件本身是绿色的, 它只会添加一些用户环境变量. 我想把环境变量备份下.

[cmdletbinding()]
param
(
    [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
    [ValidateSet('backup', 'restore')]
    [String]$operation
)

switch ($operation) {
    'backup' {
        $allEnvVarsName = (Get-ChildItem Env:).name
        
        $userEnvVars = @{ }
        foreach ($varName in $allEnvVarsName) {
            $varValue = [System.Environment]::GetEnvironmentVariable("$varName", "User")
            if ($varValue -ne $null) {
                $userEnvVars.Add($varName, $varValue)
            }
        }
        
        $userEnvVars | ConvertTo-Json | Out-File "$PSScriptRoot\userEnvVars.json" -Encoding UTF8
    }
    'restore' {
        if(!(Test-Path "$PSScriptRoot\userEnvVars.json")){
            write-output "Please backup first."
        }
        $userEnvVarsCopy = Get-Content "$PSScriptRoot\userEnvVars.json" -Encoding UTF8 | ConvertFrom-Json
        $userEnvVars = @{}
        $userEnvVarsCopy.psobject.properties | ForEach-Object { $userEnvVars[$_.Name] = $_.Value }
        
        foreach ($var in $userEnvVars.GetEnumerator()) {
            [System.Environment]::SetEnvironmentVariable($var.name, $var.value, "User")
        }
    }
}