Provides the ability to retrieve API version of a Resource Provider

AzureRmApiVersions.ps1

function Get-AzureRmApiVersion {

    <#
    .SYNOPSIS
        Get-AzureRmApiVersion returns the api versions of Resource Providers.
    .DESCRIPTION
        Provides the ability to retrieve all api versions or the latest api version of a specific Resource Provider.
    .EXAMPLE
        Get-AzureRmApiVersion -SubscriptionId $subscriptionId -Namespace "" -ResourceType "" -AccessToken $accessToken
    .LINK
        https://gist.github.com/ljtill
    #>

    [CmdletBinding()]
    param (
        [Parameter()]
        [string]$SubscriptionId,

        [Parameter()]
        [string]$Namespace,

        [Parameter()]
        [string]$ResourceType,

        [Parameter()]
        [switch]$Latest,

        [Parameter()]
        [string]$AccessToken
    )

    begin {
        $apiVersion = "2018-02-01"
        $request = @{
            Method = "GET"
            Uri = ("https://management.azure.com/subscriptions/" + $subscriptionId + "/providers?api-version=" + $apiVersion)
            Headers = @{
                "Authorization" = ("Bearer " + $accessToken)
                "Accept" = "application/json"
            }
            Body = $null
        }
    }
    
    process {
        $response = Invoke-RestMethod @request
        $response.value | ForEach-Object {
            if ($_.namespace -eq $namespace) {
                $_.resourceTypes | ForEach-Object {
                    if ($_.resourceType -eq $resourceType) {
                        if ($latest) {
                            $output = ($_.apiVersions)[0]
                        } else {
                            $output = $_.apiVersions
                        }
                    }
                }
            }
        }
    }

    end {
        return $output
    }

}