Start a Runbook with an array

Test-ObjectConversion.ps1

param(
    [Parameter(Mandatory = $true)]$Parameter
)
$Parameter.GetType()

if ($Parameter -is [array]) {
    Write-Output "It's an array. No conversion necessary."
} else {
    try {
        $Parameter = $Parameter | ConvertFrom-Json
        Write-Output "Converted from JSON to array"
    } catch {
        $Parameter = @($Parameter)
        Write-Output "Converted from String to array"
    }
}

$Parameter.GetType()

$Parameter

Test-StartRunbook.ps1

#region Connect to Azure with certificate
try {
    # Get the connection "AzureRunAsConnection "
    $servicePrincipalConnection = Get-AutomationConnection -Name "AzureRunAsConnection"
    Write-Output "Logging in to Azure..."
    Add-AzureRmAccount `
        -ServicePrincipal `
        -TenantId $servicePrincipalConnection.TenantId `
        -ApplicationId $servicePrincipalConnection.ApplicationId `
        -CertificateThumbprint   $servicePrincipalConnection.CertificateThumbprint | Out-Null
    # Switch Azure subscription
    Write-Output "Switch to Azure SubscriptionId $($servicePrincipalConnection.SubscriptionId)"
    Select-AzureRmSubscription -SubscriptionId $servicePrincipalConnection.SubscriptionId | Out-Null
} catch {
    if (!$servicePrincipalConnection) {
        throw "Connection $connectionName not found."
    } else {
        throw $_.Exception
    }
}
#endregion

$AzureAutomationRunbook = "Test-ObjectConversion"
$HybridWorker = "HybridWorkerGroup"

# Start runbook and parameter is an array
$AzureRunbookParameter = @{
    "Parameter" = "String"
}
Get-AzureRmAutomationAccount | Start-AzureRmAutomationRunbook -Parameters $AzureRunbookParameter -Name $AzureAutomationRunbook -RunOn $HybridWorker

# Start runbook and parameter is an array
$AzureRunbookParameter = @{
    "Parameter" = @("Blue","Jeans")
}
Get-AzureRmAutomationAccount | Start-AzureRmAutomationRunbook -Parameters $AzureRunbookParameter -Name $AzureAutomationRunbook -RunOn $HybridWorker

# Start runbook and parameter is an JSON
$AzureRunbookParameter = @{
    "Parameter" = ( @("Blue","Jeans") | ConvertTo-Json )
}
Get-AzureRmAutomationAccount | Start-AzureRmAutomationRunbook -Parameters $AzureRunbookParameter -Name $AzureAutomationRunbook -RunOn $HybridWorker