Verbs like New,Start,Stop that change system state should support ShouldProcess

[powershell]

Verbs like New,Start,Stop that change system state should support ShouldProcess

[raghushantha]

Feature Team - Triaged - Approved

[yutingc]

Should this rule only be applied to exported functions? There should be cases where helper functions contain these verbs in their function definition?

[quoctruong]

I was thinking maybe this should apply to function that has CmdletBinding property in the parameter?

[raghushantha]

Correct. Any function that supports cmdlet-style parameter binding needs to have this rule.

[raghushantha]

Also, ShouldProcess applies to -whatif and -confirm parameters

"Another pair of common parameters is -whatif and -confirm. Any cmdlet that makes some kind of change to the computer is supposed to recognize those. They give you the option of having the cmdlet display what it would normally do (-whatif), or have it individually confirm each action (-confirm). "

There is a good technet article on this:
https://technet.microsoft.com/en-us/magazine/ff677563.aspx

[yutingc]

So the implementation should be: if a function definition has Verbs that change system status and has CmdletBinding property in the parameter, we should make sure it also include these two attributes:ShouldProcess and ConfirmImpact.

[quoctruong]

I think that sounds good

[yutingc]

Sorry, I don't think "ConfirmImpact" should be mandatory here."ShouldProcess" is required but "ConfirmImpact" should be optional in this case.

According to MSDN:
"To support confirmation requests, the cmdlet must set the SupportsShouldProcess parameter of the Cmdlet attribute to true. This enables the Confirm and WhatIf cmdlet parameters that are provided by Windows PowerShell."

"For most cmdlets, you do not have to explicitly specify ConfirmImpact. Instead, use the default setting of the parameter, which is Medium. If you set ConfirmImpact to High, the operation will be confirmed by default. Reserve this setting for highly disruptive actions, such as reformatting a hard-disk volume."

[yutingc]

New Rule UseShouldProcessForStateChangingFunctions added (4/17).