PSAvoidAssignmentToAutomaticVariable Should detect auto-vars as function parameters

[ghost]

I did this recently and needed about 30 minutes to find my bug:

function Demo
{
    Param (
    [string] $input
    )
}

You can pass everything to this parameter, no warning, no error and $input is always $null !

See here, too: #712 "New Rule Suggestion: AvoidReuseOfAutomaticVariables"

[bergmeister]

@madmidi in PSScriptAnalyzer 1.17.1 there is already a new rule PSAvoidAssignmentToAutomaticVariable that catches assignments against the automatic variables listed here
It was decided to first start only with the read-only automatic variables because they would always result in a runtime error. Others need to be carefully considered since sometimes assignment can be by design for some of the automatic variables. I am relatively sure that we could add $input to this list though. :-)
Thanks for the feedback

[ghost]

pls have a look to the issue title.
it's not about $input, but about auto vars as function parameters !

[bergmeister]

@madmidi A function parameter with a read-only automatic variable such as $error does warn, as I said, the $input variable is just not yet part of the list of variables to warn against:

function Demo
{
    Param (
    [string] $error
    )
}

Invoke-ScriptAnalyzer C:\Users\cberg\Desktop\a.ps1

RuleName                            Severity     ScriptName Line  Message
--------                            --------     ---------- ----  -------
PSAvoidAssignmentToAutomaticVariabl Error        a.ps1      4     The Variable 'error' cannot be assigned since it is a
e                                                                 readonly automatic variable that is built into PowerShell,
                                                                  please use a different name.

[sicklittlemonkey]

I did the exact same thing last night. Half an hour of my life wasted, but I suppose at least I know about $input now.

The names for these automatic variables are truly stupid. They should have a differentiator in naming or syntax.

[fflaten]

Should be fixed by 5d529a3