Advance Function's Parameter's Get-Help is inconsistent if comment-based help is used (missing Alias, Default Value, Parameter Set, etc.)

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

Enter in the following code

function Test-GreetingA {
    [CmdletBinding()]
    param (
        [Parameter(
            Position = 0,
            Mandatory,
            ValueFromPipeline
        )]
        [Alias(
            'Subject'
        )]
        [string]
        $Person
    )
    
    begin {
        
    }
    
    process {
        Write-Output "Hello $Person"
    }
    
    end {
        
    }
}



<#
.SYNOPSIS
Test a simple greeting

.DESCRIPTION
A simple greeting that requires a person's name

.PARAMETER Person
The person you want to greet

.EXAMPLE
Test-Greeting -Person 'John Smith'
#>
function Test-GreetingB {
    [CmdletBinding()]
    param (
        [Parameter(
            Position = 0,
            Mandatory,
            ValueFromPipeline
        )]
        [Alias(
            'Subject'
        )]
        [string]
        $Person
    )
    
    begin {
        
    }
    
    process {
        Write-Output "Hello $Person"
    }
    
    end {
        
    }
}

Now run the following Get-Help commands

Get-Help Test-GreetingA -Parameter Person
Get-Help Test-GreetingB -Parameter Person

Expected behavior

-Person <string>

    Required?                    true
    Position?                    0
    Default value                None
    Accept pipeline input?       true (ByValue)
    Parameter set name           (All)
    Aliases                      Subject
    Dynamic?                     false
    Accept wildcard characters?  false

-Person <String>
    The person you want to greet

    Required?                    true
    Position?                    0
    Default value                None
    Accept pipeline input?       true (ByValue)
    Parameter set name           (All)
    Aliases                      Subject
    Dynamic?                     false
    Accept wildcard characters?  false

Actual behavior

-Person <string>
    
    Required?                    true
    Position?                    0
    Accept pipeline input?       true (ByValue)
    Parameter set name           (All)
    Aliases                      Subject
    Dynamic?                     false
    Accept wildcard characters?  false


-Person <String>
    The person you want to greet

    Required?                    true
    Position?                    1
    Default value
    Accept pipeline input?       true (ByValue)
    Aliases
    Accept wildcard characters?  false

Error details

Incorrect output includes (disparity between Get-Help's output for Test-GreetingA vs. Test-GreetingB):

• 'Default value' is missing (A)
• 'Position' is incremented (B)
• 'Parameter set name' is missing (B)
• 'Dynamic' is missing (B)
• 'Default value' right hand value is not showing (B)
• 'Aliases' right hand value is not showing (B)

Environment data

Name                           Value
----                           -----
PSVersion                      7.5.1
PSEdition                      Core
GitCommitId                    7.5.1
OS                             Microsoft Windows 10.0.22631
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Visuals

Reproduisez l’écart avec les deux fonctions Test-GreetingA et Test-GreetingB, puis comparez la sortie de Get-Help pour leurs paramètres Person. C’est terminé lorsque l’aide basée sur les commentaires conserve de manière cohérente la valeur Default attendue, Position, le nom du jeu de paramètres, Aliases, Dynamic et les champs associés, comme l’aide basée sur la syntaxe.