Fix for chocolatey#3364

… v7.4+

Make export of legacy `TabExpansion` function conditional on the PowerShell version.

… v7.4+

By using the new Register-ArgumentCompleter API

TabExpansion is not used since PowerShell 7.4, so the export of legacy
`TabExpansion` function is made conditional on the PowerShell version.

diff --git a/src/chocolatey.resources/helpers/ChocolateyTabExpansion.ps1 b/src/chocolatey.resources/helpers/ChocolateyTabExpansion.ps1
index 149bcd08..6c1f164e 100644
--- a/src/chocolatey.resources/helpers/ChocolateyTabExpansion.ps1
+++ b/src/chocolatey.resources/helpers/ChocolateyTabExpansion.ps1
@@ -264,26 +264,50 @@ if ($PowerTab_RegisterTabExpansion) {
     return
 }

-if (Test-Path Function:\TabExpansion) {
-    Rename-Item Function:\TabExpansion TabExpansionBackup
-}
-
-function TabExpansion($line, $lastWord) {
-    $lastBlock = [System.Text.RegularExpressions.Regex]::Split($line, '[|;]')[-1].TrimStart()
+# PowerShell up to v7.3.x: use a custom TabExpansion function.
+if ($PSVersionTable.PSVersion.Major -lt 7 -or ($PSVersionTable.PSVersion.Major -eq 7 -and $PSVersionTable.PSVersion.Minor -lt 4)) {
+    if (Test-Path Function:\TabExpansion) {
+        Rename-Item Function:\TabExpansion TabExpansionBackup
+    }

-    switch -regex ($lastBlock) {
-        # Execute Chocolatey tab completion for all choco-related commands
-        "^$(Get-AliasPattern choco) (.*)" {
-            ChocolateyTabExpansion $lastBlock
-        }
+    function TabExpansion($line, $lastWord) {
+        $lastBlock = [System.Text.RegularExpressions.Regex]::Split($line, '[|;]')[-1].TrimStart()
+

-        # Fall back on existing tab expansion
-        default {
-            if (Test-Path Function:\TabExpansionBackup) {
-                TabExpansionBackup $line $lastWord
+        switch -regex ($lastBlock) {
+            # Execute Chocolatey tab completion for all choco-related commands
+            "^$(Get-AliasPattern choco) (.*)" {
+                ChocolateyTabExpansion $lastBlock
+            }
+
+            # Fall back on existing tab expansion
+            default {
+                if (Test-Path Function:\TabExpansionBackup) {
+                    TabExpansionBackup $line $lastWord
+                }
             }
         }
     }
+} else { # PowerShell v7.4+: use the Register-ArgumentCompleter cmdlet (PowerShell no longer calls TabExpansion)
+    function script:Get-AliasNames($exe) {
+        @($exe) + @(Get-Alias | Where-Object { $_.Definition -eq $exe } | Select-Object -Exp Name)
+    }
+
+    Register-ArgumentCompleter -Native -CommandName (Get-AliasNames choco) -ScriptBlock {
+        param($wordToComplete, $commandAst, $cursorColumn)
+
+        # NOTE:
+        # * The stringified form of $commandAst is the command's own command line (irrespective of
+        #   whether other statements are on the same line or whether it is part of a pipeline).
+        # * However, trailing whitespace is trimmed in the string representation of $commandAst.
+        #   Therefore, when the actual command line ends in space(s), they must be added back
+        #   so that ChocolateyTabExpansion recognizes the start of a new argument.
+        $ownCommandLine = [string] $commandAst
+        $ownCommandLine = $ownCommandLine.Substring(0, [Math]::Min($ownCommandLine.Length, $cursorColumn))
+        $ownCommandLine += ' ' * ($cursorColumn - $ownCommandLine.Length)
+
+        ChocolateyTabExpansion $ownCommandLine
+    }
 }

 # SIG # Begin signature block
diff --git a/src/chocolatey.resources/helpers/chocolateyProfile.psm1 b/src/chocolatey.resources/helpers/chocolateyProfile.psm1
index a9968117..252d60af 100644
--- a/src/chocolatey.resources/helpers/chocolateyProfile.psm1
+++ b/src/chocolatey.resources/helpers/chocolateyProfile.psm1
@@ -25,7 +25,11 @@ Import-Module "$thisDirectory\Chocolatey.PowerShell.dll" -Cmdlet "Get-Environmen
 . $thisDirectory\functions\Write-FunctionCallLogMessage.ps1
 . $thisDirectory\ChocolateyTabExpansion.ps1

-Export-ModuleMember -Alias refreshenv -Function 'Update-SessionEnvironment', 'TabExpansion'
+$funcs = @('Update-SessionEnvironment')
+if ($PSVersionTable.PSVersion.Major -lt 7 -or ($PSVersionTable.PSVersion.Major -eq 7 -and $PSVersionTable.PSVersion.Minor -lt 4)) {
+    $funcs += 'TabExpansion' # Legacy TabExpansion function is only used up to PowerShell v7.3.x
+}
+Export-ModuleMember -Alias refreshenv -Function $funcs

 # SIG # Begin signature block
 # MIInKwYJKoZIhvcNAQcCoIInHDCCJxgCAQExDzANBglghkgBZQMEAgEFADB5Bgor

… v7.4+

By using the new Register-ArgumentCompleter API

TabExpansion is not used since PowerShell 7.4, so the export of legacy
`TabExpansion` function is made conditional on the PowerShell version.

… v7.4+

By using the new Register-ArgumentCompleter API

TabExpansion is not used since PowerShell 7.4, so the export of legacy
`TabExpansion` function is made conditional on the PowerShell version.

… v7.4+

By using the new Register-ArgumentCompleter API

TabExpansion is not used since PowerShell 7.4, so the export of legacy
`TabExpansion` function is made conditional on the PowerShell version.

The newer method is available from v5 and up, so we have no need to wait
for v7.4+ to change over. This will also let us remove the fallback
earlier, once we no longer support PS <5.0.

… v7.4+

By using the new Register-ArgumentCompleter API

TabExpansion is not used since PowerShell 7.4, so the export of legacy
`TabExpansion` function is made conditional on the PowerShell version.

The newer method is available from v5 and up, so we have no need to wait
for v7.4+ to change over. This will also let us remove the fallback
earlier, once we no longer support PS <5.0.

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

These tests are verifying the old method and are targeting an
implementation detail, rather than actually checking the tab completion
results, which the following tests do anyway.

As such, we're best off skipping them as there is no direct way to check
the same things for the Register-ArgumentCompleter method. The tests for
the tab completion results themselves covers this adequately already.

These tests are verifying the old method and are targeting an
implementation detail, rather than actually checking the tab completion
results, which the following tests do anyway.

As such, we're best off removingthem as there is no direct way to check
the same things for the Register-ArgumentCompleter method. The tests for
the tab completion results themselves covers this adequately already.

These tests are verifying the old method and are targeting an
implementation detail, rather than actually checking the tab completion
results, which the following tests do anyway.

As such, we're best off removing them as there is no direct way to check
the same things for the Register-ArgumentCompleter method. The tests for
the tab completion results themselves cover this adequately already.

(#3364) Remove unusable tab completion tests