PowerShell guidelines for -Confirm, -Force, and -WhatIf

Question

Are there any official guidelines from Microsoft about when to add -Confirm, -Force, and -WhatIf parameters to custom PowerShell cmdlets?

Answer 1

If you want to validate that your implementation of these common parameters is compliant to the guidelines (for example, Set-Xxx cmdlets should have -Confirm and -WhatIf), then you can use the excellent PsScriptAnalyzer module (which is based on code analysis).

Make sure the module is installed:

PS E:\> Install-Module -Name 'PsScriptAnalyzer'

Then run PowerShell Code Analysis as follows:

PS E:\> Invoke-ScriptAnalyzer -Path . | FL

RuleName : PSUseShouldProcessForStateChangingFunctions
Severity : Warning 
Line     : 78 
Column   : 10 
Message  : Function 'Update-something' has verb that could change system state. 
           Therefore, the function has to support 'ShouldProcess'.

Documentation (and sources) can be found on GitHub: https://github.com/PowerShell/PSScriptAnalyzer