Function Parameter Not its own TextMate Scope

No repository files or tests are named. Reproduce the examples in VS Code, inspect the TextMate scopes before and after saving, and trace the PowerShell grammar entry point responsible for parameter tokens. Done means function parameters are scoped separately from their values and the highlighting remains consistent after saving.

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest version
• Search the existing issues.

Steps to reproduce

1. Open VS Code
2. Open new un-saved PowerShell file
3. Paste the following into the window:

$EventLog = "EventLog"
Get-Service -Name EventLog
Get-Service -Name 'EventLog'
Get-Service -Name "EventLog"
Get-Service -Name ('EventLog')
Get-Service -Name $EventLog
Get-Service -Name $($EventLog)
Get-Service -Name @($EventLog)
Get-Service -Name ${EventLog}
Get-Service -Name:$($EventLog)
Get-Service -Name:EventLog

Result:

4. Save File anywhere
   Results:

Expected behavior

On save the syntax highlighting will remain the same as the first screenshot.

Actual behavior

On saving the file the syntax highlighting does not display appropriately, see second screenshot

Error details

n/a

Environment data

Name                           Value
----                           -----
PSVersion                      7.5.4
PSEdition                      Core
GitCommitId                    7.5.4
OS                             Microsoft Windows 10.0.26200
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

Version

latest? Visual Studio Code Host Version 2025.4.0

Visuals

See above screenshots for visuals. Also below:

Parameter & Parameter Value Separated by a space " " or colon ":" are seen as a single token when using the "Developer: Inspect Editor Tokens and Scopes" feature

Where the others are seen as separate because of another character: ' " ( $ @

Ideally, a function parameter (dash followed by letters and then separated by specific characters) should be it's own TextMate Scope / token that can be customized separate from the rest