{DO NOT MERGE} (GH-1609) Remove syntax folder provider feature

[glennsarti]

THIS PR SHOULD NOT BE MERGED UNTIL PowerShell/PowerShellEditorServices#777 is merged

PR Summary

Now that the PowerShell Editor Services has a Folding Provider, this extension
based feature is no longer required. This commit removes the feature and tests.

The PSES Issue #793 [1] tracks the work to add it to PSES.

[1] PowerShell/PowerShellEditorServices#793

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Fixes #1609

[rjmholt]

Just to make sure, VSCode itself implements the client-side folding right? So we don't need to add any new handling for the server-side provider ourselves?

[rjmholt]

We should link to the relevant VSCode feature documentation in the issue

[glennsarti]

I haven't seen the source code but this what I've observed;

1. If the language server says it provides a Folding Provider VSCode uses that.
2. If the extension registers a FoldingProvider then VSCode uses that.
3. Otherwise it defaults to the indentation default folder within VSCode

[rjmholt]

Oh right, so the registration is in the FoldingProvider.Enable (or whatever it is) part of the initialisation message response?

[glennsarti]

We should link to the relevant VSCode feature documentation in the issue

AFAIK There is no explicit documentation on this

[glennsarti]

Oh right, so the registration is in the FoldingProvider.Enable (or whatever it is) part of the initialisation message response?

Yes. The logic in PSES is;

1. The Server says it supports folding and the folder is enabled.
2. The Client (VSCode) later sends the DidChangeConfiguration notification which then enables or disables the folder in PSES

[rjmholt]

AFAIK There is no explicit documentation on this

Bugger. I'll keep searching just so we have a few signposts on how it all works.

[glennsarti]

The deep internal reference documentation of VSCode isn't the greatest :-(

https://github.com/Microsoft/vscode/blob/957518fdffe5b62262e957e2f942e373f825312a/src/vs/editor/contrib/folding/folding.ts

https://github.com/Microsoft/vscode/blob/0ac0c45b29c9c138e39c4b12602302650d9e405c/src/vs/editor/common/modes.ts#L1343

This is probably no different that a Document Symbol provider or Hover provider or Completion provider.

[TylerLeonhardt]

If this is really as simple as it sounds and we just need to remove the feature client-side this looks good to me!

[glennsarti]

Works on my machine. Would appreciate someone on Mac and/or Ubuntu to try it out.

[TylerLeonhardt]

Checked out your code in both repos. Can confirm, works on macOS 😄

Folding a here string worked perfectly and settings updates were automatically applied.

[rjmholt]

👍

[cpdohert]

The new syntax folding doesn't work correctly. Prior to this PR, "Fold All" did what I expect: function definitions collapsed into a single line, etc. Now, folding is randomly collapsing more than a single function/stanza, or not an entire function/stanza. Syntax folding is essentially completely broken for our PowerShell module authoring as of this PR. I can't easily provide examples witout violating company NDA, but if I am not the only one with this issue I can generate representative code that displays the problem.

[rjmholt]

Hi @cpdohert, thanks for the feedback. The issue tracking this is #1631. The fix is being worked on in PowerShell/PowerShellEditorServices#805.