(#3364) Fix broken tab completion (expansion) in PowerShell v7.4+

[mklement0]

Description Of Changes

Switches to using Register-ArgumentCompleter for tab-completion (expansion) when running in PowerShell v7.4+

Motivation and Context

As discussed in #3364:

• Chocolatey's tab completion broke in v7.4.0, due to an intentional breaking change in PowerShell (removal of legacy code, as a side effect of which PowerShell no longer calls custom TabExpansion functions, if defined).

• The recommended approach (since v5.0) is to use Register-ArgumentCompleter

Testing

• Interactively (tab completion).

• Programmatically, by calling TabExpansion2; e.g:

(TabExpansion2 ($c = 'choco c') -cursorColumn $c.Length).CompletionMatches.CompletionText | 
  Should -Be cache, config
(TabExpansion2 ($c = 'choco l later') -cursorColumn 7).CompletionMatches.CompletionText |
  Should -Be list

Operating Systems Testing

Windows 11 22H2

Change Types Made

• Bug fix (non-breaking change).
• Feature / Enhancement (non-breaking change).
• Breaking change (fix or feature that could cause existing functionality to change).
• Documentation changes.
• PowerShell code changes.

Change Checklist

• Requires a change to the documentation.
• Documentation has been updated.
• Tests to cover my changes, have been added.
• All new and existing tests passed?
• PowerShell code changes: PowerShell v2 compatibility checked?

I don't have access to PowerShell v2, but I think the changes are compatible.

Related Issue

Fixes #3364

[yan12125]

How do you think about using Register-ArgumentCompleter on PowerShell >= 5.0 instead of PowerShell >= 7.4? That will help #2255 for users on a little bit older PowerShell.

[mklement0]

I tried to be conservative, but, yes, it should be possible to use Register-ArgumentCompleter in v5+

However, support for choco.exe is really a separate issue (I just happened to add it to the v7.4+ code - though I just reverted it, because it was incomplete and introduces an asymmetry).

The only thing needed to enable it for the v7.3- code is the following:

Change the $aliases=... line in:

function Get-AliasPattern($exe) {
    $aliases = @($exe) + @(Get-Alias | Where-Object { $_.Definition -eq $exe } | Select-Object -Exp Name)

    "($($aliases -join '|'))"
}

to:

    $aliases = @($exe, "$exe\.exe") + @(Get-Alias | Where-Object { $exe, "$exe.exe" -contains $_.Definition } | Select-Object -Exp Name)

If the maintainers are fine with this, I'm happy to update the PR to add choco.exe support in all versions.

[yan12125]

Oops, I misunderstood the issue about choco.exe. Many thanks for the kind explanation!

[silverqx]

I tried this PR and it works well, everything looks good short, long parameters, completion of commands and also completion of package names.

This PR lgtm. Why it's still not merged?