language-tools: Significant lag and performance degradation in VSCode with Volar on

For peoples who still has performance issue with latest version, you can try:

1. Disable javascript.suggest.autoImports and typescript.suggest.autoImports in workspace settings.
2. Try enable volar.vueserver.useSecondServer in workspace settings for better performance, or disable it for less memory usage.
3. Delete node_modules and check did problems gone or not. If yes, delete package.json dependencies / devDependencies one by one to see which package lead to problems. (If this is the reason, the package usually has lot of .d.ts files.)
4. Try Takeover mode.
5. (Advanced) Investigate (Performance Tracing)[https://github.com/microsoft/TypeScript-wiki/blob/main/Performance-Tracing.md] use vue-tsc.

Close this issue because do not have anymore helpful information, if you can confirm the performance from plugin, please open a new issue with append repro case or profiling record.

It’s too slow to use

I can confirm this on my system as well. It’s quite ridiculous waiting for insights take +5-10s and makes it impossible to get insights with any sort of speed.

再现个鬼， 你开个2000行左右的vue文件，插件提示直接歇菜，慢得一批~！换回vuter后，一切正常~！

Okay, this looks like your first issue, how about to take a look at what others are doing? I think we all know disabling extension to avoid it couldn’t help anything, so why not do something more meaningful, like try and see if something like this happens to you? 😃

再现个鬼， 你开个2000行左右的vue文件，插件提示直接歇菜，慢得一批~！换回vuter后，一切正常~！

WebStorm now also uses Volar and it takes almost 9 seconds for the error to disappear. Deleting node_modules and package-lock.json didn’t fixed the issue.

https://github.com/vuejs/language-tools/assets/6358971/e8bb548b-2cc5-44f5-b3bd-37792adfc794

What helps is switching Volar with the TypeScript Service. I could try to create some repository where you could reproduce it, but I don’t want to share it publicly here. Also I can’t guarantee it will reproduce in VSCode.

The current version of Volar does not have much overhead, but its performance is limited by TypeScript. If your project itself is a huge TypeScript project, TypeScript LanguageService will analyze it slowly anyway. If you can provide a repro case, I might be able to help find out the performance hotspots in your project. It may come from a certain dependency, or some recursive type. At least the performance problems I have checked recently are all from the project itself.

If you need help please provide a repro case and open a new issue, I’ll find time to check it, otherwise I can’t help, I’m not a magician.

Removing

"editor.codeActionsOnSave": ["source.organizeImports"]

from my global settings, did the trick. Hope it helps.

@Noxdor I try mitigate memory leak by https://github.com/johnsoncodehk/volar/commit/7337d1c1fef9f51c70387e9352e7e4914800ea2d, please try v0.40.3.

Thanks for the reply! As I wrote above, for me the issue was already resolved and I am right now on 0.40.1. So it can’t have been the changes in 0.40.3. Unfortunately I can’t pinpoint it any more precisely.

@onurusluca Sorry just typo, I mean v0.39.2 released later than this issue open.

Created a new issue on this: https://github.com/johnsoncodehk/volar/issues/1663

@johnsoncodehk Thanks a lot for the reply. Sorry for not specifying the problem. I chose v0.38.5 because the next update from that has a longer gap.

I am testing all the versions now. It is taking a bit of a time. I will write here as soon as I am done testing.

Also great job with the extension. I love Volar!

@onurusluca Thank for the information, is this problem begin in v0.38.6?

v0.38.5 ~ v0.38.6 only have one commit and it should be unrelated, so I’m out of ideas for now.

• https://github.com/johnsoncodehk/volar/commit/d8559b4c66c1c96e2ca2d4c98f3e2a901e39a067

I still can’t reproduce this performance issue, I may need someone try with each commit after v0.38.5 and let me know which commit cause the problem.

I can also confirm this. It suddenly got slow. I uninstalled VsCode and it’s settings, cleaned cached, did general cleaning but still slow.

@brys0 Please let me know if this version have difference or not: volar-0.39.5-alpha.1.vsix.zip

Tried this one but it is the same. Thanks for your time though. Hope this gets solved.

For now I downgraded to v0.38.5 and syntax highlighting got much faster just like before.

I figured it may have been an issue with typescript trying to work with 2 different versions. Lovely you found the issue, thanks for taking your personal time to fix it. Much love 🤍

I’ve removed every extension did a fresh install of vscode and just installed Volar and it’s still just as slow. I have no idea what might be happening, based on what you said it could be related to certain node modules? Such as @vicons libraries causing Volar to scan the entire module which has upwards of 300+ vue files. Any advice for other people is I would consider somehow removing intelisense on large node modules like naive-ui and any icon library that directly uses .vue files.

• (If this is a recent issue) Which version did this issue start appearing?
• Do you have update typescript version? And what’s is your typescript version? (See status bar when opened .vue file)
• Can this problem alleviate by setting "javascript.suggest.autoImports": false and "typescript.suggest.autoImports": false in VSCode?

Okay, I’ll try to change these settings to test when I get back to work next week; I suspect the lag may be related to some of the node processes not being closed properly, which may take some time to occur with use, so it’s not immediately reproducible.