Extension slow to respond

[brunnerh]

Describe the bug
Getting auto-completion, symbol navigation or symbol information can be very slow (tooltip stuck on Loading...).
(It is probably the language server, because the profile from "Running Extensions" does not pick it up as causing CPU load.)

To Reproduce
Invoke commands like "Trigger Suggest" and "Go to Definition".

As for the conditions necessary to cause the slowdown, i am not sure. It may have to do with using carbon-components-svelte/carbon-icons-svelte which introduce a lot of Svelte files.
The "Output" panel shows this for Svelte:

SnapshotManager File Statistics:
Project files: 26022
Svelte files: 7210
From node_modules: 33251
Total: 33276

Expected behavior
Language features are reasonably fast.

Screenshots

System (please complete the following information):

• OS: Windows 10, 64bit
• IDE: VSCode
• Plugin/Package: Svelte for VSCode

[jasonlyu123]

I did encounter a similar issue before. Still can't found out why, but it maybe is slowing down in the typescript language service part. It only pops up occasionally for me so this is not easy to debug.
Some other context might help. Do you use pnpm? There's seem to be some pnpm issues in the typescript repo. And what version of svelte for vscode you're using? if it's 105.3.3, does roll back to 105.3.1 helps? Or does turning off typescript.suggest.includeCompletionsForImportStatements and javascript.suggest.includeCompletionsForImportStatements helps?

[stolinski]

We're having major slowdown and often get a pop up saying that VSCode is waiting of the Svelte formatter.

Some details
v. 105.3.3
Svelte Kit App
TS for js
Scss for css
NOT using pnpm, just npm.

Giving typescript.suggest.includeCompletionsForImportStatements a try

[jasonlyu123]

I publish a new version(105.3.4). Hope this would address the performance issues you're facing.

[brunnerh]

That might have fixed it. Right now the file statistics do not grow as much as previously:

SnapshotManager File Statistics:
Project files: 21
Svelte files: 6
From node_modules: 382
Total: 404

[brunnerh]

I will have to revoke that statement.
After working on a Svelte file, opening a new element tag, trying to get import suggestions, it started to load a lot of the other files again and slowed down to a crawl.

SnapshotManager File Statistics:
Project files: 26022
Svelte files: 6
From node_modules: 26040
Total: 26066
SnapshotManager File Statistics:
Project files: 26022
Svelte files: 7
From node_modules: 26041
Total: 26067
SnapshotManager File Statistics:
Project files: 26022
Svelte files: 2420
From node_modules: 28454
Total: 28480

Turning off the includeCompletionsForImportStatements options might have helped, but i should probably test a bit longer.

After a while with includeCompletionsForImportStatements turned off i also managed to trigger a load of thousands of files again, more or less freezing the server

SnapshotManager File Statistics:
Project files: 26022
Svelte files: 7
From node_modules: 26041
Total: 26066
SnapshotManager File Statistics:
Project files: 26022
Svelte files: 3080
From node_modules: 29114
Total: 29139
SnapshotManager File Statistics:
Project files: 26022
Svelte files: 6294
From node_modules: 32328
Total: 32353

[brunnerh]

Tried downgrading to version 105.3.1; it also has this problem.
I am not using pnpm.

I think that i could work or Carbon projects without the freezes at some point. When I have some more time i could try to bisect the extension version, but any help in that regard would also be appreciated.

[jasonlyu123]

Do you have a tsconfig.json or jsconfig.json? It looks like maybe your problem isn't about the recent updates.

[brunnerh]

My tsconfig.json currently looks like this:

{
	"compilerOptions": {
		"strict": true,
		"moduleResolution": "node",
		"target": "es6",
		"lib": ["ES2020", "DOM", "DOM.Iterable"],
		"sourceMap": true,
		"importsNotUsedAsValues": "error", /* for svelte-preprocess */
		"resolveJsonModule": true,
		"allowSyntheticDefaultImports": true,
		"allowJs": true,
		"skipLibCheck": true,
	},
	"exclude": ["out/**/*"],
}

I can also try to put together a repro repository later.

[jasonlyu123]

You can try excluding node_modulus and build directories like __sapper__ or .svelte-kit. From the number of svelte files, I guess it is some sort of hashed generated files.

[brunnerh]

This does not use sapper or svelte-kit.
Have a look at what carbon-icons-svelte exposes: https://unpkg.com/carbon-icons-svelte@10.36.0/lib/index.js
All of those are separate .svelte files.

If i were to exclude that, i would lose the completion for that, though, right?

[jasonlyu123]

carbon-icons-svelte have provided typescript definitions. So it's safe to exclude the source files.

[brunnerh]

I tried excluding node_modules, worked on a project for a few hours and the issue did not come up.

[dummdidumm]

Did the slowness in any way creep back or can we close this?