Skip to content

Add validation to prevent duplicate alias names and definitions #27505

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
jserygit wants to merge 5 commits into
base: master
Choose a base branch
from
+29 −0
Open

Add validation to prevent duplicate alias names and definitions #27505

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
ad712c4
Add validation to prevent alias name and definition from being the sa…
jserygit May 22, 2026
aee0cf6
Add blank line for improved readability in NewAliasCommand and SetAli…
jserygit May 22, 2026
2e36d6d
Implement alias name validation in NewAliasCommand and SetAliasComman…
jserygit May 26, 2026
7d4b190
Merge branch 'master' of https://github.com/jserygit/PowerShell into …
jserygit May 26, 2026
89585ab
CodeFactor: Remove region in WriteAliasCommandBase
jserygit May 26, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions src/Microsoft.PowerShell.Commands.Utility/commands/utility/NewAliasCommand.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using System;
using System.Management.Automation;
using System.Management.Automation.Internal;

Expand Down Expand Up @@ -58,6 +59,8 @@ protected override void ProcessRecord()
}
}

ValidateAliasName();

// Create the alias info

AliasInfo newAlias =
Expand Down
2 changes: 2 additions & 0 deletions src/Microsoft.PowerShell.Commands.Utility/commands/utility/SetAliasCommand.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using System;
using System.Management.Automation;
using System.Management.Automation.Internal;

Expand Down Expand Up @@ -30,6 +31,7 @@ protected override void ProcessRecord()
Option);

aliasToSet.Description = Description;
ValidateAliasName();

string action = AliasCommandStrings.SetAliasAction;

Expand Down
16 changes: 16 additions & 0 deletions src/Microsoft.PowerShell.Commands.Utility/commands/utility/WriteAliasCommandBase.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,9 @@
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using System;
using System.Management.Automation;
using System.Management.Automation.Internal;

namespace Microsoft.PowerShell.Commands
{
Expand Down Expand Up @@ -84,5 +86,19 @@ public SwitchParameter Force

private bool _force;
#endregion Parameters

/// <summary>
/// Validates the alias name is not the same as the value.
/// </summary>
/// <exception cref="ArgumentException">Thrown when the alias name is the same as the value.</exception>
protected internal void ValidateAliasName()
{
if (string.Equals(Name, Value, StringComparison.OrdinalIgnoreCase))
{
throw new ArgumentException(
StringUtil.Format(AliasCommandStrings.InvalidAliasName, Name),
nameof(Name));
}
}
}
}
3 changes: 3 additions & 0 deletions src/Microsoft.PowerShell.Commands.Utility/resources/AliasCommandStrings.resx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -168,4 +168,7 @@
<data name="NoAliasFound" xml:space="preserve">
<value>This command cannot find a matching alias because an alias with the {0} '{1}' does not exist.</value>
</data>
<data name="InvalidAliasName" xml:space="preserve">
<value>The alias name '{0}' is not valid. Alias names must be unique and cannot be the same as existing commands.</value>
</data>
</root>
5 changes: 5 additions & 0 deletions test/powershell/Modules/Microsoft.PowerShell.Utility/New-Alias.Tests.ps1
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,11 @@ Describe "New-Alias DRT Unit Tests" -Tags "CI" {
$result.Description | Should -BeExactly "test description"
$result.Options | Should -BeExactly "None"
}

It "New-Alias Should throw an error when the alias name and value are the same" {
{ New-Alias -Name ABCD -Value ABCD -Scope "0" -ErrorAction Stop } |
Should -Throw -ErrorId "System.ArgumentException,Microsoft.PowerShell.Commands.NewAliasCommand"
}
}

Describe "New-Alias" -Tags "CI" {
Expand Down