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

使用两个函数 Test-GreetingA 和 Test-GreetingB 重现差异，然后比较它们的 Person 参数的 Get-Help 输出。当基于注释的帮助与基于语法的帮助一致地保留预期的 Default 值、Position、Parameter set name、Aliases、Dynamic 及相关字段时，即表示完成。