Test support for Powershell intellisense in Codepilot chat code blocks

Prerequisites

• I have written a descriptive issue title.
• I have searched all issues to ensure it has not already been reported.

Summary

VS Code recently enabled intellisense in copilot chat code blocks. Although this is mostly implemented in a language agnostic way, language extensions may need to make some changes to get the best support

For this exploration, I'd like your team's help testing out Powershell IntelliSense in copilot chat code blocks. I've provided a list of ideas on what to test below, however feel free to build on it. I've gone through them for JS/TS and found them to be a good starting point. You can also file feature request against VS Code for new feature ideas

Areas to test

• Your extension should see TextDocuments for each code block present in a copilot chat

  These documents have the scheme: vscode-chat-code-block.

• Basic syntax language features — such bracket matching and Smart Selection — should always work

• You should never see errors reported for code in chat code blocks

  Try asking copilot to generate invalid code to confirm this

• Test hovers and go to definition within a single code block

  For example if you ask for looping over array in powershell, there should be a single code block that has these IntelliSense features

  • Make sure these features work for global symbols
  • Also test IntelliSense for symbols defined within the block
  • Check that any special Powershell features in hovers (such as links) work as expected
  • Make sure the code block IntelliSense observes any relevant workspace/project settings

• Test cross-code block IntelliSense

  Subsequent code blocks should be able to use variables and functions defined in earlier blocks first

• Test IntelliSense for workspace symbols

  This feature is mostly handled by copilot but still worth testing. For it, as a @workspace question to find code in the workspace. For example, @workspace where's the code for parsing arguments

  • Make sure can use hover, go to definition for symbols that come from the workspace
  • Make sure you can still use these features for globals and locals too

• Make sure that code in code blocks is never picked up as a reference

  If a code block uses a global symbol for example, when you run find all references on that symbol in a normal workspace file, you should not see the use in the code block listed

• Make sure symbols code blocks never shows up in workspace symbol search

• Explore any Powershell specific features/behavior of these IntelliSense features inside these chat code blocks

• Think about if there's any additional IntelliSense features that would help users understand code inside of chat code blocks

Proposed Design

No response

Start in VS Code Copilot Chat by exercising the listed scenarios with PowerShell code blocks, including single-block, cross-block, workspace-symbol, and reference-search behavior. Verify the vscode-chat-code-block documents and record any missing or incorrect IntelliSense behavior; the work is done when the extension's behavior across the checklist is documented and any needed follow-up is identified.