Get-AzResourceProviderApiVersion.ps1

function Get-AzResourceProviderApiVersion {
    <#
    .SYNOPSIS
    Lists the available API version(s) for a given Resource Provider and optionally for the specified Resource Type(s)
 
    .PARAMETER ProviderNamespace
    Resource PRovider namespace to return the API version(s) for
 
    .PARAMETER ResourceTypes
    Optional Resource Type for the passed Resource Provider
 
    .EXAMPLE
    Get-AzResourceProviderApiVersion -ProviderNamespace Microsoft.Automation
 
    2018-06-30
    2018-01-15
    2017-05-15-preview
    2015-10-31
    2015-01-01-preview
 
    Returns the available APIs across all ResourceTypes for the Resource Provider (Microsoft.Automation).
 
    .EXAMPLE
    Get-AzResourceProviderApiVersion -ProviderNamespace Microsoft.Automation -ResourceTypes automationaccounts
 
    ResourceTypeName ApiVersions
    ---------------- -----------
    automationAccounts {2018-06-30, 2018-01-15, 2017-05-15-preview, 2015-10-31...}
 
    Returns the available APIs for the specified ResourceType under the Resource Provider
 
    .EXAMPLE
    Get-AzResourceProviderApiVersion -ProviderNamespace Microsoft.Automation -ResourceTypes automationAccounts, automationAccounts/runbooks
 
    ResourceTypeName ApiVersions
    ---------------- -----------
    automationAccounts {2018-06-30, 2018-01-15, 2017-05-15-preview, 2015-10-31...}
    automationAccounts/runbooks {2018-06-30, 2018-01-15, 2017-05-15-preview, 2015-10-31...}
 
    Returns the available APIs for the specified ResourceTypes under the Resource Provider
    #>


    [CmdletBinding()]
    param (
        [parameter(Mandatory, Position = 0, ValueFromPipeline, ValueFromPipelineByPropertyName)]
        [string]$ProviderNamespace,

        [parameter(Position = 1, ValueFromPipelineByPropertyName)]
        [string[]]$ResourceTypes
    )

    process {
        if ([string]::IsNullOrWhiteSpace($ResourceTypes)) {
            Get-AzResourceProvider -ProviderNamespace $ProviderNamespace | Select-Object -ExpandProperty 'ResourceTypes' | Select-Object -ExpandProperty 'ApiVersions' -Unique
        }
        else {
            foreach ($type in $ResourceTypes) {
                Get-AzResourceProvider -ProviderNamespace $ProviderNamespace |
                    Select-Object -ExpandProperty 'ResourceTypes' |
                    Where-Object 'ResourceTypeName' -EQ $type |
                    Select-Object @{l = 'ResourceTypeName'; e = { $_.ResourceTypeName } }, ApiVersions
            }
        }
    }
}