IntelliSense doesn't honor comment-based help for script files (`.ps1`), absent or broken syntax diagrams

Prerequisites

• I have written a descriptive issue title.
• I have searched all open and closed issues to ensure it has not already been reported.
• I have read the troubleshooting guide.
• I am sure this issue is with the extension itself and does not reproduce in a standalone PowerShell instance.
• I have verified that I am using the latest version of Visual Studio Code and the PowerShell extension.
• If this is a security issue, I have read the security issue reporting guidance.

Summary

IntelliSense with respect to script files (.ps1) that have comment-based help - as opposed to functions - currently has the following problems:

• Their synopsis is not shown, because their comment-based help is seemingly not consulted.

• The formatting of their syntax diagrams is broken: the individual diagrams aren't separated with empty lines and instead form one long string without line breaks, resulting in arbitrary line wrapping. Situationally - as in the repro below - no syntax diagrams are shown at all.

PowerShell Version

Name             : Visual Studio Code Host
Version          : 2024.0.0
InstanceId       : 63cceb1e-397a-4b02-989f-55f2c40757c7
UI               : System.Management.Automation.Internal.Host.InternalHostUserInterface
CurrentCulture   : en-US
CurrentUICulture : en-US
PrivateData      : Microsoft.PowerShell.ConsoleHost+ConsoleColorProxy
DebuggerEnabled  : True
IsRunspacePushed : False
Runspace         : System.Management.Automation.Runspaces.LocalRunspace

Visual Studio Code Version

1.85.2
8b3775030ed1a69b13e4f4c628c612102e30a681
arm64

Extension Version

ms-vscode.powershell@2024.0.0

Steps to Reproduce

• Create a sample script with comment-based help and multiple parameter sets.

@'
<#
.SYNOPSIS
Foo's description.
#>
param(
  [Parameter(ParameterSetName='Foo')]
  $Foo,
  [Parameter(ParameterSetName='Bar')]
  $Bar
)
'@ > Foo.ps1

• Run (Get-Help ./Foo.ps1).synopsis and (Get-Help ./Foo.ps1).syntax to verify that both the comment-based help

• In Visual Studio Code, in the same folder, type ./Foo in order to show IntelliSense

As the screenshot shows, neither the description nor the syntax diagrams are shown.

Visuals

Logs

No response

Start by reproducing the issue with the sample Foo.ps1 script and compare IntelliSense output with (Get-Help ./Foo.ps1).synopsis and (Get-Help ./Foo.ps1).syntax. Trace the extension's script-file help and syntax handling; done means the synopsis appears and multiple syntax diagrams are separated by line breaks in IntelliSense.