Also here’s an editor command you can use to test if TabExpansion2 gives the same result:

Register-EditorCommand -DisplayName 'Show Engine Completion Results' -Name EditorTabExpansion2 -ScriptBlock {
    param(
        [Microsoft.PowerShell.EditorServices.Extensions.EditorContext, Microsoft.PowerShell.EditorServices]
        $Context
    )
    end {
        function GetLineMap {
            [OutputType([int[]])]
            param([string] $text)
            end {
                $lineStartMap = [System.Collections.Generic.List[int]]::new(100)
                $lineStartMap.Add(0)
                for ($i = 0; $i -lt $text.Length; ++$i) {
                    $c = $text[$i];
    
                    if ($c -eq "`r"[0]) {
                        if (($i + 1) -lt $text.Length -and $text[$i + 1] -eq "`n"[0]) {
                            $i++;
                        }
    
                        $lineStartMap.Add($i + 1)
                    }
    
                    if ($c -eq "`n") {
                        $lineStartMap.Add($i + 1);
                    }
                }
    
                return ,$lineStartMap.ToArray()
            }
        }

        $fileContext = $Context.CurrentFile
        $scriptAst = $fileContext.Ast
        $scriptTokens = $fileContext.Tokens

        $scriptText = $scriptAst.Extent.Text
        $lineStartMap = GetLineMap $scriptText
        $offset = ($lineStartMap[$Context.CursorPosition.Line - 1] + $Context.CursorPosition.Column) - 1
        $newPosition = $scriptAst.Extent.StartScriptPosition.GetType().
            GetMethod(
                <# name: #> 'CloneWithNewOffset',
                <# bindingAttr: #> [System.Reflection.BindingFlags]'NonPublic, Public, Instance',
                <# binder: #> $null,
                <# types: #> [type[]][int],
                <# modifiers: #> $null).
            Invoke($scriptAst.Extent.StartScriptPosition, @($offset))

        $completionMatches = [System.Management.Automation.CommandCompletion]::
            CompleteInput($scriptAst, $scriptTokens, $newPosition, @{}).
            CompletionMatches

        if (-not $completionMatches) {
            Write-Host
            Write-Host 'CompleteInput returned no matches.'
            return
        }

        $completionMatches | Out-Host
    }
}

    {
        "key": "ctrl+shift+space",
        "command": "PowerShell.InvokeRegisteredEditorCommand",
        "args": { "commandName": "EditorTabExpansion2" },
        "when": "editorTextFocus && editorLangId == 'powershell'",
    },

COol 😄 I will be using the comma workaround in near future.

FYI I updated the editor command above and added a key bind of <kbd>Ctrl</kbd> + <kbd>Shift</kbd> + <kbd>Space</kbd>. Hopefully that makes it a little easier to test this kind of thing.

Also, another work around is adding a pipe, e.g.

# This works, remove the | and it doesn't.
New-Function -Test1 New,<tab> |
somethingelsehere

Doesn’t work for me:

Edit… oh it works

I guess I could use it that way 💯

As a work around, it seems like if you type an extra <kbd>,</kbd> and tab complete before it it works.

e.g. New-Function -Test1 New -Test2 Other,, > <kbd>Left Arrow</kbd> > <kbd>Tab</kbd>

@SeeminglyScience - well

Nothing shows up on line 8

@PrzemyslawKlys in the ISE example you showed, the <kbd>,</kbd> character is being used as line continuation. If you look at the syntax highlighting in the ISE you’ll see the second line is being treated as input to the first command.

@vexx32 IndexOf is putting the cursor index at <here>-Test2

Should I open it up in PowerShell repo? as it seems PS5.1 / 7.1 as well.

Quick and dirty repro:

$script = @'
function New-Function {
        [cmdletBinding()]
        param(
            [validateSet('New', 'Old', 'Other')][string[]] $Test1,
            [validateSet('New', 'Old', 'Other')][string[]] $Test2
        )
    }
    New-Function -Test1 New -Test2 
    New-Function -Test1 New, Old -Test2 New
    New-Function -Test1 New, Old -Test2 New
'@

$cursorColumn = $script.IndexOf('-Test2 ')
TabExpansion2 -inputScript $script -cursorColumn $cursorColumn | % completionmatches

The symptom seems to show up essentially when you have the same function used later on in the script, and then you return to an earlier function call to the same function and start to tab complete it. It reproduces in a completely separate console as well, safe to say it’s not the VS Code extension itself.

The completions I get from this are the generic “here’s a list of files from the current dir” sort of completions, completely ignoring the validateset results or not finding them for some reason.

Looks like it’s down to something in PS. 😞

Thanks @PrzemyslawKlys we are trying to determine whether this issue is occurring in PowerShell or in Editor Services, but it is a bit difficult for us to check without the full program. If you take this program and find the offset of where your completion is in relation to the script, you should be able to use tabexpansion2 to determine if the error in completion reproduces.

TabExpansion2 -inputScript @'
import-module MyModule
get-process -Name
get-childitem
'@ -cursorColumn 41 | %{​​​​ $_.CompletionMatches }​​​​