Failed to call the method because [Sitecore.Data.Items.Item] does not contain a method named "op_Addition"

Question

I am trying to execute this script but it is throwing an error.

$path = "/sitecore/content/home"
$root = Get-Item $path
$items = Get-ChildItem $path -Recurse
($items += $root) | Where-Object { $_.TemplateName -eq "Product" -or $_.TemplateName -eq "Accessory" } | ForEach-Object {
    Write-Log "Hi"
}

This part is throwing an error: ($items += $root).

Error:

Failed to call the method because [Sitecore.Data.Items.Item] does not contain a method named "op_Addition"

Answer 1

Marek's answer is correct and addresses the error, but it's worth bearing in mind that in the situation posted, you have a simpler option available to you:

$path = "/sitecore/content/home"
$items = Get-ChildItem $path -Recurse -WithParent

The -WithParent parameter will automatically include the root item for you.

Answer 2

Your code works ok when there are multiple items returned from Get-ChildItem command.

If only 1 item is returned, SPE returns single item object instead of an array.

You can work around the issue by wrapping both $root and $items variables with @(...) like:

$path = "/sitecore/content/home"
$root = @(Get-Item $path)
$items = @(Get-ChildItem $path -Recurse)
($items += $root) | ForEach-Object {
    $_.Name
}