Upgrade to latest O# LangaugeServer Extension

[NTaylorMullen]

https://www.nuget.org/packages/OmniSharp.Extensions.LanguageServer/

• Will be able to remove our AutoFlushingStream impl

• Make sure that hovers/completions/whatnot work on HTMLY files.

• Try removing AutoFlushingStream

Needs Verification in VS:

• SemanticTokens (Ryan)
• Completions
• Completion resolve
• signatureHelp
• documentHighlight
• codeAction
• codeLens
• formatting
• onTYpeFormatting
• rename

Needs Verification in VSCode:

• SemanticTokens (Ryan)
• Hover
• Completions
• Completion resolve
• signatureHelp
• documentHighlight
• codeAction
• codeLens
• formatting
• onTYpeFormatting
• rename

[TanayParikh]

Remove comment: https://github.com/dotnet/aspnetcore-tooling/pull/1948/files#diff-0d41ccb18ff91a95cbd69267725546adR169-R170

[NTaylorMullen]

Should validate this: https://dev.azure.com/devdiv/DevDiv/_workitems/edit/1173891?src=WorkItemMention&src-action=artifact_link

Once completed

[NTaylorMullen]

And this: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1174096?src=WorkItemMention&src-action=artifact_link

Looks to be the same

[NTaylorMullen]

I believe this will also resolve: https://github.com/dotnet/aspnetcore/issues/25116

[ryanbrandenburg]

Post-upgrade problems:

• No codelens in vscode or VS
• No completions in VS
• No signatureHelp in VSCode
• Lightbulb on unknown taghelper hangs in VS
• Rename doesn't work in VS
• OnTypeFormatting doesn't work in VS
• AutoCompletion doesn't work in VS
• VSCode gives errors about Synchronization failed: Token cancellation requested: undefined

[TanayParikh]

Lightbulb on unknown taghelper hangs in VS

So something like:
<NonExistantComponent> -> invoke lightbulb -> VS hangs?

Or unknown as in missing a using / fully qualified namespace?

[ryanbrandenburg]

Like your example, except instead of "invoke lightbulb" it's just "click on the lightbulb (assumedly just to get a list of available actions)"