PowerShell function to check Azure CLI version

Require-AzCliVersion.ps1

function Require-AzCliVersion {
    [OutputType([void])]
    param(
        [Parameter(Mandatory, ValueFromPipeline)] [ValidatePattern("^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,9}$")] [string] $Version,
        [switch] $Fail
    )
    $actual = ('az version' | Invoke-Expression | ConvertFrom-Json).'azure-cli'  
    if ($actual -eq $Version) {
        "Azure CLI present in pinned version $Version" | Write-Verbose
    } else {
        $message = "Azure CLI present in version $actual. Pinned version is $Version"
        if ($Fail) {
            $message | Write-Error; exit 1
        } else {
            $message | Write-Warning
        }
    }
}