ParameterSets not being honored

PowerShell Help
1
Hi guys,
I decided to take a stab at trying to do a parameterset.
param
(
    [Parameter(Mandatory = $true,
                    Position = 0)]
    [ValidateSet('Production', 'DR')]
    [string]$env,
    [Parameter(Mandatory = $true,
                    Position = 1)]
    [ValidateLength(8, 8)]
    [string]$date,
    [Parameter(Position = 2)]
    [pscredential]$credential,
    [Parameter(ParameterSetName = 'PPgroup')]
    [switch]$PP,
    [switch]$incoming,
    [Parameter(ParameterSetName = 'Agroup')]
    [switch]$A
)
 
What i am expecting is that when i use PP that I can only see incoming . However when I use the parameter a that it does not show incoming. However when I use the parameter a the option for PP goes away but incoming still remains. What gives?
Any help appreciated.
2

I would define $date as [Datetime] rather than a [string], and I would separate $pp from $incoming as in:

function TestParameterSets {
    param
        (
            [Parameter(Mandatory = $true, Position = 0)]
            [ValidateSet('Production', 'DR')]
            [string]$env,
        
            [Parameter(Mandatory = $true, Position = 1)]
            [dateTime]$date,
        
            [Parameter(Position = 2)]
            [pscredential]$credential,
        
            [Parameter(ParameterSetName = 'PPgroup')]
            [switch]$PP,
            
            [Parameter(ParameterSetName = 'PPgroup')]
            [switch]$incoming,
        
            [Parameter(ParameterSetName = 'Agroup')]
            [switch]$A
        )

    "env        = $env"
    "date       = $date"
    "credential = $(if ($credential) {""(that of '$($credential.UserName)')""} else {$credential}) "
    "pp         = $pp"
    "incoming   = $incoming"
    "A          = $A"
}

Results match expectations:

TestParameterSets -env DR -date (Get-Date) -credential (Get-Credential samb) -incoming 

env        = DR
date       = 02/27/2020 07:17:13
credential = (that of 'samb')
pp         = False
incoming   = True
A          = False

TestParameterSets -env Production -date (Get-Date) -credential (Get-Credential samb) -A 
env        = Production
date       = 02/27/2020 07:13:46
credential = (that of 'samb')
pp         = False
incoming   = False
A          = True

$Incoming shows as $false when using ‘Agroup’ parameterset because it’s declared as a switch which defaults to $false.

I would also make at least one of the unique parameters of each parameter set mandatory. For example $PP and $A. To avoid the error: ‘Parameter set cannot be resolved using the specified named parameters.’