Fix Get-Help PSTypeName issue with -Parameter when only one parameter is declared

[pougetat]

PR Summary

Fix #8697 'Get-Help -Parameter does not correctly set PSTypeName when one parameter is declared'.

PR Context

This issue occurs for the following reason :

• For a single parameter the FullHelp object contains a PSObject representing the parameter
• For multiple parameters the FullHelp object conrains a PSObject[] with each element representing a parameter.
  My fix is to manipulate a PSObject[] instead of a PSObject even in the event that it only contains one parameter.

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .h, .cpp, .cs, .ps1 and .psm1 files have the correct copyright header
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: or [ WIP ] to the beginning of the title (the WIP bot will keep its status check at Pending while the prefix is present) and remove the prefix when the PR is ready.
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed
    • Issue filed:
• Testing - New and feature
  • N/A or can only be tested interactively
  • OR
  • Make sure you've added a new test if existing tests do not effectively test the code changed
    • Add [feature] to your commit messages if the change is significant or affects feature tests

[vexx32]

You could probably condense much of this into the ternary statement, if I'm reading this right...

Suggested change

	paramAsPSObjArray != null ? paramAsPSObjArray : param,
	paramPSObjArray == null ? paramPSObjArray : new[] { (PSObject)prmts.Properties["parameter"].Value },

[pougetat]

The problem is that param is not necessarily PSObject or PSObject[]. It can also be object which makes the cast failure prone.

[vexx32]

You can do PSObject.AsPSObject(obj) to safely convert object -> PSObject, but I'm not sure whether that would completely resolve the issue.

That method will also no-op if the input object is already a PSObject.

[pougetat]

I don't think it resolves the issue since that method will attempt to create a PSObject from object. What I'm doing here is essentially trying to use the object as is in the form of a PSObject and if it doesn't work then I will just pass the object along to ConvertTo as was done previously. ConvertTo itself knows what to do with a plain object in regards to transforming it into a PSObject.

[vexx32]

I'm not 100% sure, but I think that's more or less just what ConvertTo would do itself... I'd have to chase down the convoluted code paths in there, though. I'm sure it's OK to use ConvertTo, though. 🙂

[adityapatwardhan]

@pougetat Thank you for your contribution!