Improved Carapace PowerShell completer code

[tahir-hassan]

Carapace PowerShell Completer code

I have re-written the Carapace PowerShell completer code:

using namespace System.Management.Automation
using namespace System.Management.Automation.Language
using namespace System.Collections.Generic
using namespace System.Diagnostics.CodeAnalysis

$_carapace_completer = {
	[SuppressMessageAttribute("PSAvoidUsingInvokeExpression", "", Scope = "Function", Target = "*")]
	param([string]$wordToComplete, [CommandAst]$commandAst, [int]$cursorPosition)

	$elems = [List[string]]::new();

	foreach ($commandElem in $commandAst.CommandElements) {
		if ($cursorPosition -lt $commandElem.Extent.StartOffset) {
			break;
		} else {
			$text = if ($commandElem.StaticType -eq [string]) {
				$commandElem.Value
			} else {
				$commandElem.Extent.Text
			}
			$elems.Add($text);
		}
	}

	$elems[0] = $elems[0] -replace '\.exe$', '';
	if (-not $wordToComplete) {
		$elems.Add("");
	}

	[CompletionResult[]]$completions =
		carapace $elems[0] powershell $elems |
		ConvertFrom-Json |
		ForEach-Object { [CompletionResult]::new($_.CompletionText, $_.ListItemText.replace('`e[', "`e["), [CompletionResultType]::ParameterValue, $_.ToolTip.replace('`e[', "`e[")) };

	if ($completions) {
		$completions
	} else {
		$lastElem = $elems[-1];
        # either 1. no word to complete, 2. contains an asterisk, 3. starts with either ./ .\ which means file path 4. all lowercase
		if ($lastElem -eq '' -or $lastElem.Contains("*") -or $lastElem -match "^\.[/\\]" -or $lastElem -cnotmatch "[A-Z]") {
			return; # trigger default powershell completion
		} else {
			"" # prevent default file completion - user intended to have command arg completion
		}
	}
}

Improvements

• It is greatly simplified
• Allows powershell default completion in certain cases, for example lowercase file completion.

Questions

• Is there any way I can integrate my code into Carapace?
• Are there any test cases?

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Thank you for your time.