1
2using namespace System.Management.Automation
3using namespace System.Management.Automation.Language
4
5Register-ArgumentCompleter -Native -CommandName 'my-app' -ScriptBlock {
6    param($wordToComplete, $commandAst, $cursorPosition)
7
8    $commandElements = $commandAst.CommandElements
9    $command = @(
10        'my-app'
11        for ($i = 1; $i -lt $commandElements.Count; $i++) {
12            $element = $commandElements[$i]
13            if ($element -isnot [StringConstantExpressionAst] -or
14                $element.StringConstantType -ne [StringConstantType]::BareWord -or
15                $element.Value.StartsWith('-') -or
16                $element.Value -eq $wordToComplete) {
17                break
18        }
19        $element.Value
20    }) -join ';'
21
22    $completions = @(switch ($command) {
23        'my-app' {
24            [CompletionResult]::new('-h', 'h', [CompletionResultType]::ParameterName, 'Print help')
25            [CompletionResult]::new('--help', 'help', [CompletionResultType]::ParameterName, 'Print help')
26            break
27        }
28    })
29
30    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
31        Sort-Object -Property ListItemText
32}
33