Semantic highlighting (`encodedSemanticClassifications-full`) extremely slow

[PawelJ-PL]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: 1.57.0-1623259737
• OS Version: Debian GNU/Linux 11 (bullseye)

In 1.57.0-1623259737 version IntelliSense is terribly slow. I've no Idea, what more details should I provide. I've tested it on TypeScript/React project (also with all extensions disabled - with the same result - loading hint takes more than 10 seconds).

After downgrade to 1.56.2-1620838498 everything works great.

[randomprogramming]

Same issue here, will try downgrading and see if that helps at all.

[bl-ue]

Python here, not slow for me at all. 🤔

[mjbvz]

Please either share a project that causes this or try collecting the TS Server log:

1. Set "typescript.tsserver.log": "verbose",
2. Restart VS Code and reproduce the problem
3. In VS Code, run the TypeScript: Open TS Server log command
4. This should open a large log file called tsserver.log

If you can share the log, I can a look to see if anything stands out

⚠️Warning: The TypeScript log may include information from your workspace, including file paths and source code. If you have any concerns about posting this publicly on Github, just let me know and we can arrange something else. On our side, we only use these logs to investigate issues like this

[nalejandroveron]

I'm sharing a log about this issue, seeing it on the last update and even without extensions enabled:
tsserver.log

[nalejandroveron]

There are instances of encodedSemanticClassifications-full on the logs it took more than 7 seconds, is that normal? I think that's the only interesting thing that I saw on this logfile:

    {"seq":54,"type":"request","command":"encodedSemanticClassifications-full","arguments":{"file":"/Users/negan/Projects/Firesquad/firesquad-widget/packages/widget/src/FiresquadWidget/index.tsx","start":791,"length":2560,"format":"2020"}}
Perf 306  [23:37:31.425] 54::encodedSemanticClassifications-full: elapsed time (in milliseconds) 7258.0516

Only followed by some open files (+2 seconds):

Open files: 
Info 95   [23:36:43.742] 	FileName: /Users/negan/Projects/Firesquad/firesquad-widget/packages/widget/src/FiresquadWidget/index.tsx ProjectRootPath: /Users/negan/Projects/Firesquad/firesquad-widget
Info 95   [23:36:43.742] 		Projects: /Users/negan/Projects/Firesquad/firesquad-widget/packages/widget/tsconfig.json
Perf 95   [23:36:43.742] 2::updateOpen: elapsed time (in milliseconds) 2642.9740

[PawelJ-PL]

Attached my log file

tsserver.log

[PawelJ-PL]

I also noticed with affected version that even if I manage to load the list of hints, it is not complete.

[rrdelaney]

Reverting to 1.56 fixed the slowness for me too. Didn't seem to matter if I used TS 4.2 or 4.3.

[RisaI]

Can confirm, I also had to revert to 1.56.

[aarbmx6s]

Had the same problem.
I disabled TypeScript validation in Settings > Workspace > Extensions > TypeScript section.

.vscode/settings.json:

{
  "typescript.validate.enable": false
}

[outranker]

Had the same problem.
I disabled TypeScript validation in Settings > Workspace > Extensions > TypeScript section.

.vscode/settings.json:

{
  "typescript.validate.enable": false
}

how was the result after disabling the feature?

[aarbmx6s]

Had the same problem.
I disabled TypeScript validation in Settings > Workspace > Extensions > TypeScript section.
.vscode/settings.json:

{
  "typescript.validate.enable": false
}

how was the result after disabling the feature?

Well, I use only IntelliSense for faster coding and with this feature disabled I do not waiting for 5-15 sec to get suggestions. If I have some errors with types or any other mistakes in source code I get errors while my project recompiles.

[rrdelaney]

Update: this may be related to TypeScript 4.3? After updating our codebase to TS43 VSCode's Intellisense has slowed down to a crawl even when using 1.56.2.

[aarbmx6s]

Had the same problem.
I disabled TypeScript validation in Settings > Workspace > Extensions > TypeScript section.

.vscode/settings.json:

{
  "typescript.validate.enable": false
}

Update: after several days Intellisense became slow again.