Add ValidateNotNullOrEmpty attribute to the -Property of Format-Table/List/Custom#26552
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daxian-dbw merged 2 commits intoPowerShell:masterfrom Jan 12, 2026
Merged
Add ValidateNotNullOrEmpty attribute to the -Property of Format-Table/List/Custom#26552daxian-dbw merged 2 commits intoPowerShell:masterfrom
ValidateNotNullOrEmpty attribute to the -Property of Format-Table/List/Custom#26552daxian-dbw merged 2 commits intoPowerShell:masterfrom
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Pull request overview
This PR fixes issue #26543 by adding the ValidateNotNullOrEmpty attribute to the -Property parameter of Format-Table, Format-List, and Format-Custom cmdlets to prevent null reference exceptions when empty arrays or null values are passed.
Key Changes:
- Added validation attribute to prevent null/empty Property values in Format-Table, Format-List, and Format-Custom
- Added comprehensive test coverage for all three cmdlets verifying both null and empty array scenarios throw appropriate validation errors
Reviewed changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/System.Management.Automation/FormatAndOutput/common/BaseFormattingCommand.cs | Added ValidateNotNullOrEmpty attribute to the Property parameter in OuterFormatTableAndListBase class, which is inherited by Format-Table and Format-List |
| src/Microsoft.PowerShell.Commands.Utility/commands/utility/FormatAndOutput/format-object/Format-Object.cs | Added ValidateNotNullOrEmpty attribute to the Property parameter in FormatCustomCommand class |
| test/powershell/engine/Formatting/BugFix.Tests.ps1 | Added test cases to verify that Format-Table, Format-List, and Format-Custom properly throw ParameterArgumentValidationError when Property is passed null or empty array |
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SeeminglyScience
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Jan 12, 2026
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PR Summary
Fix #26543
Add the
ValidateNotNullOrEmptyattribute to the parameter-PropertyforFormat-Table,Format-List, andFormat-Custom.This is to fix the null reference exception when using an empty array as the argument for
-Property.Breaking Change
It's a breaking change as today you can use
$nullas the argument forFormat-List/Table/Custom, which behaves the same as-Propertyis not specified. By adding theValidateNotNullOrEmptyattribute,-Property $nullwill fail. But this may fall in the bucket 3 (grey area) though.PR Checklist
.h,.cpp,.cs,.ps1and.psm1files have the correct copyright header