PSShouldProcess behavior allows for unsafe code to pass where it should fail

Steps to reproduce

The following function will pass PSShouldProcess

function Test-Fail {
    [CmdletBinding(SupportsShouldProcess)]
    param ()
    process {
        Remove-Item -Path C:\temp\a_testy.txt -Force -Confirm:$false -ErrorAction SilentlyContinue
    }
}

@seeminglyscience pointesd me to this
https://github.com/PowerShell/PSScriptAnalyzer/blob/a7d23f7f4dbf4ee92077f5471e28ca334caef429/Rules/UseShouldProcessCorrectly.cs#L245-L267

Where it is checking upstream functions for supports should process. While on the surface it may seem like a good idea to allow the upstream functions to handle the confirmation, this allows for some unsafe code to pass where it should fail.

IMO, the best course would be to always warn when $PSCmdlet.ShouldProcess() is not present in the function itself and require suppression when allowing the upstream functions to handle the confirmation.

Expected behavior

Either a warning or the requirement to suppress PSShouldProcess

Actual behavior

Test passes

Environment data

> $PSVersionTable
Name                           Value
----                           -----
PSVersion                      5.1.16299.251
PSEdition                      Desktop
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.16299.251
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
> (Get-Module -ListAvailable PSScriptAnalyzer).Version | ForEach-Object { $_.ToString() }
1.16.0
1.15.0
1.13.0
1.12.0
1.8.1
1.16.1

Inizia da Rules/UseShouldProcessCorrectly.cs, in particolare dal controllo della funzione upstream intorno alle righe 245-267, e riproduci il problema con la funzione PowerShell mostrata. Conferma che l'analizzatore segnali il comportamento mancante di $PSCmdlet.ShouldProcess() o richieda una soppressione, quindi aggiungi la copertura per l'avviso previsto o per il requisito di soppressione.