fix: say that a missing New-NTFSHardLink target does not exist

Defect 21. For a -Target that didn't exist, New-NTFSHardLink failed with
"The target path exist, cannot create the link", the opposite of the
cause. The message now names the target and says that it does not exist.

Tests/Links.Tests.ps1 (new): 2 tests, one of them for a link that is
created.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: AI Assistant <ai@example.com>

CHANGELOG.md

@@ -124,5 +124,7 @@ The format is based on
   the unchanged state of an item also when the change failed, so that the
   inheritance looked disabled
   ([#74](https://github.com/raandree/NTFSSecurity/issues/74))
+- Fix the error of `New-NTFSHardLink` for a missing `-Target`, which said
+  that the target path existed
 
 [Unreleased]: https://github.com/raandree/NTFSSecurity/compare/4.2.6...HEAD

Docs/Cmdlets/New-NTFSHardLink.md

@@ -138,6 +138,8 @@ The cmdlet does not overwrite anything. If `-Path` already exists, or if `-Targe
 
 Because all names of a file share the same data, the number of hard links is a property of the file, not of an individual name. Use `Get-NTFSHardLink` to list them, and delete a link with `Remove-Item2` or `Remove-Item`, which removes only that name as long as other names remain.
 
+Before 5.0.0, the error for a missing `-Target` said "The target path exist", the opposite of the cause.
+
 ## RELATED LINKS
 
 [Get-NTFSHardLink](Get-NTFSHardLink.md)

NTFSSecurity/LinkCmdlets/NewHardLink.cs

@@ -63,7 +63,7 @@ namespace NTFSSecurity
                     throw new ArgumentException(string.Format("The file '{0}' does already exist, cannot create the link", path));
 
                 if (!TryGetFileSystemInfo2(target, out temp))
-                    throw new ArgumentException("The target path exist, cannot create the link");
+                    throw new ArgumentException(string.Format("The target '{0}' does not exist, cannot create the link", target));
                 else
                     if (temp is DirectoryInfo)
                     throw new ArgumentException("The target is not a file, cannot create the link");

NTFSSecurity/en-US/NTFSSecurity.dll-Help.xml

@@ -7135,6 +7135,7 @@ PS C:\Data&gt; Get-NTFSSecurityDescriptor</dev:code>
         <maml:para>Windows supports hard links only for files on the same NTFS volume. A link that points to a file on another volume, or a target on a file system that does not implement hard links, cannot be created.</maml:para>
         <maml:para>The cmdlet does not overwrite anything. If `-Path` already exists, or if `-Target` is missing or is a folder, the cmdlet reports an error and leaves the file system unchanged.</maml:para>
         <maml:para>Because all names of a file share the same data, the number of hard links is a property of the file, not of an individual name. Use `Get-NTFSHardLink` to list them, and delete a link with `Remove-Item2` or `Remove-Item`, which removes only that name as long as other names remain.</maml:para>
+        <maml:para>Before 5.0.0, the error for a missing `-Target` said "The target path exist", the opposite of the cause.</maml:para>
       </maml:alert>
     </maml:alertSet>
     <command:examples>

Tests/Links.Tests.ps1

@@ -0,0 +1,44 @@
+<#
+    Tests the link cmdlets of the module built in NTFSSecurity\bin\Release in a sandbox folder.
+#>
+[Diagnostics.CodeAnalysis.SuppressMessageAttribute(
+    'PSUseDeclaredVarsMoreThanAssignments', '', Justification = 'Pester shares variables between blocks.'
+)]
+param ()
+
+BeforeAll {
+    Import-Module -Name (Join-Path -Path $PSScriptRoot -ChildPath 'TestHelpers.psm1') -Force
+    $modulePath = Join-Path -Path $PSScriptRoot -ChildPath '..\NTFSSecurity\bin\Release\NTFSSecurity.psd1'
+    Import-Module -Name $modulePath -Force -ErrorAction Stop
+    $sandbox = New-TestSandbox -Name 'Links'
+    Push-Location -LiteralPath $sandbox
+}
+
+AfterAll {
+    Pop-Location
+    Remove-TestSandbox -Sandbox $sandbox
+    Remove-Module -Name NTFSSecurity -Force -ErrorAction SilentlyContinue
+}
+
+Describe 'New-NTFSHardLink' {
+    It 'Should create a hard link to a file' {
+        $target = New-TestSandboxItem -Sandbox $sandbox -Name 'Target'
+        $link = Join-Path -Path $sandbox -ChildPath 'Link.txt'
+        Assert-TestSandboxPath -Sandbox $sandbox -Path $link
+
+        New-NTFSHardLink -Path $link -Target $target -ErrorAction Stop
+
+        $link | Should -Exist
+        Get-Content -LiteralPath $link | Should -Be (Get-Content -LiteralPath $target)
+    }
+
+    # Before 5.0.0, the error said "The target path exist" for a target that did not exist.
+    It 'Should report that a missing target does not exist' {
+        $missing = Join-Path -Path $sandbox -ChildPath 'Missing.txt'
+        $link = Join-Path -Path $sandbox -ChildPath 'MissingLink.txt'
+        Assert-TestSandboxPath -Sandbox $sandbox -Path $missing, $link
+
+        { New-NTFSHardLink -Path $link -Target $missing -ErrorAction Stop } | Should -Throw -ExpectedMessage '*does not exist*'
+        $link | Should -Not -Exist
+    }
+}