Implement HelpMessage in the interactive console

[rjmholt]

(Should be a PowerShellEditorServices issue, but here for visibility)

Moved from microsoft/vscode#59042.

The ReadLine of the custom host does not support the HelpMessage parameter setting:

function Test-ParametersAndPrompts {
    [cmdletbinding()]
    param(
        [parameter(Mandatory, HelpMessage = 'Enter the location of the folder.')]
        [string]
        $Path
    )

    process {
        $path
    }
}

Running Test-ParametersAndPrompts in the Integrated Console correctly prompts for the Path parameter, but does not support the ?! input to get the help message.

[rjmholt]

Marking this as up-for-grabs. The relevant code should be here: https://github.com/PowerShell/PowerShellEditorServices/tree/master/src/PowerShellEditorServices/Console

[theJasonHelmick]

Recently ran across this issue working with MSLearning trying to create an advanced function in vscode and test the HelpMessage with mandatory parameters.

[rjmholt]

It's possible this will be solved by PowerShell/PowerShellEditorServices#1295, where the host is being reimplemented. As I return to that work, I'll try and see if we perform this correctly.

[bgelens]

@rjmholt Just ran into this today as well

[rjmholt]

@bgelens consider adding a 👍 to help us prioritise

[bytor75]

Still not working