From b3e805159ef2426e184b5e7a0fccb54c918ed89f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Jare=C5=A1?= <me@jakubjares.com>
Date: Sun, 19 Jul 2026 12:07:19 +0200
Subject: [PATCH] Clear TestDrive with .NET IO instead of per-item Remove-Item
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Clear-TestDrive ran Remove-Item -Path -Force -Recurse for every new root
item after each block. Remove-Item costs ~470us per item where
IO.Directory/IO.File Delete costs ~85us, and -Path treats the path as a
wildcard pattern, so a file named like 'file[1].txt' was never deleted and
leaked across block teardowns. The .NET calls treat the path literally,
delete reparse points without following them into their target (same as
Remove-TestDrive already does for the whole drive since 2021), and anything
that throws (read-only files on Windows, locked files) falls back to
Remove-Item -LiteralPath -Force -ErrorAction Ignore, keeping the old
semantics for those.

Also replaced a Join-Path with plain string interpolation in
New-RandomTempRegistry, registry provider paths always use backslash.

🤖
---
 src/functions/TestDrive.ps1    | 23 ++++++++++++++++++++---
 src/functions/TestRegistry.ps1 |  3 ++-
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/functions/TestDrive.ps1 b/src/functions/TestDrive.ps1
index c6570c2a7..74231a430 100644
--- a/src/functions/TestDrive.ps1
+++ b/src/functions/TestDrive.ps1
@@ -131,12 +131,29 @@ function Clear-TestDrive {
             [System.StringComparer]::OrdinalIgnoreCase)
 
         # Only delete "root" new items (those whose parent directory is not also a new item).
-        # Deleting with -Recurse removes all descendants in one call, avoiding redundant
-        # Remove-Item calls on already-deleted children.
+        # Deleting recursively removes all descendants in one call, avoiding redundant
+        # deletions of already-deleted children.
         foreach ($item in $newItemSet) {
             $parent = [IO.Path]::GetDirectoryName($item)
             if (-not $newItemSet.Contains($parent)) {
-                & $SafeCommands['Remove-Item'] -Path $item -Force -Recurse -ErrorAction Ignore
+                # .NET deletes are ~5x faster than Remove-Item and treat the path literally, so
+                # bracket or wildcard characters in file names no longer glob (Remove-Item -Path
+                # left a file named like 'file[1].txt' behind). Directory.Delete removes reparse
+                # points (symlinks, junctions) without following them into their target, same as
+                # Remove-TestDrive already does for the whole drive. Read-only or locked items throw
+                # and fall back to Remove-Item, which keeps the previous -Force -ErrorAction Ignore
+                # semantics for those.
+                try {
+                    if ([IO.Directory]::Exists($item)) {
+                        [IO.Directory]::Delete($item, $true)
+                    }
+                    else {
+                        [IO.File]::Delete($item)
+                    }
+                }
+                catch {
+                    & $SafeCommands['Remove-Item'] -LiteralPath $item -Force -Recurse -ErrorAction Ignore
+                }
             }
         }
     }
diff --git a/src/functions/TestRegistry.ps1 b/src/functions/TestRegistry.ps1
index d8386bfcd..4eb401746 100644
--- a/src/functions/TestRegistry.ps1
+++ b/src/functions/TestRegistry.ps1
@@ -95,7 +95,8 @@ function Invoke-TestRegistryWithRetry {
 function New-RandomTempRegistry {
     do {
         $tempPath = Get-TempRegistry
-        $Path = & $SafeCommands['Join-Path'] -Path $tempPath -ChildPath ([IO.Path]::GetRandomFileName().Substring(0, 4))
+        # registry provider paths always use backslash; plain interpolation avoids a per-call cmdlet invocation
+        $Path = "$tempPath\$([IO.Path]::GetRandomFileName().Substring(0, 4))"
         # Test-Path is a read operation and can throw the same transient IOException as the
         # New-Item write below, so retry it the same way.
         $keyAlreadyExists = Invoke-TestRegistryWithRetry { & $SafeCommands['Test-Path'] -Path $Path -PathType Container }