Intellisense for never before imported libraries doesnt work

[EldinHb]

Describe the bug

When you install a Svelte library and then try to use a Svelte component in any .svelte file the intellisense cant find the library. When you add import {} from 'library'; in any other file intellisense is able to find any component of said library.

Screenshots with https://tabler.io/docs/icons/svelte as the library. Could also reproduce with https://www.skeleton.dev/.

No intellisense for any icon.

Intellisense works with import {} from '@tabler/icons-svelte'; in same file.

Intellisense works with import {} from '@tabler/icons-svelte'; in another unused .svelte file.

Reproduction

Create new sveltekit project.

Pick empty project with typescript and no other libraries.

Install https://tabler.io/docs/icons/svelte

See the screenshots in the above description.

Expected behaviour

Intellisense to work with never before imported libraries.

System Info

• OS: macOS
• IDE: vscode

Which package is the issue about?

Svelte for VS Code extension

Additional Information, eg. Screenshots

No response

[jasonlyu123]

This is expected because the type definition is only loaded if there is an import to it. Loading arbitrary d.ts files from node_modules might cause some performance problems. In TypeScript projects, the auto-import also behaves like this.

But in the js projects, the automatic type acquisition will also discover some of the direct dependencies in a child process. This is a feature that we didn't support, so I am marking this issue as a feature request instead of a bug.

[EldinHb]

Do you mean in regular typescript projects that aren't svelte projects? I've never seen this in regular typescript projects or react projects. It works smoothly and I haven't seen performance issues in those projects.

[jasonlyu123]

Yes. It's the same. I tried in a ts file in a plain typescript project with only a tsconfig and in a SvelteKit project. They both don't provide auto-import for newly installed packages.

js projects, i.e. those without tsconfig.json or those with a jsconfig.json. Those are provided by automatic type acquisition running in another process. And we don't support that.

[EldinHb]

Thats weird because I dont experience the same in projects/files that dont use the Svelte LSP. Both are newly created with freshly installed packages.

Edit:

It also works in .ts files in a sveltekit project. The only place it doesnt work is in .svelte files.

[jasonlyu123]

Hmm. That's weird. That's different from what I saw in both Windows and Ubuntu WSL. Maybe you have some extension or config that changes the default behaviour?

[jasonlyu123]

Ah. Found it. It's https://www.typescriptlang.org/docs/handbook/release-notes/typescript-4-0.html#smarter-auto-imports. From the implementation notes. devDependencies is excluded from this discovery. That's why I kept not getting it. This is indeed not provided by automatic type acquisition. But unfortunately, this is a TypeScript internal API, and it's not something we can switch on easily. It's still a feature request that needs quite some work to enable.

[EldinHb]

Glad you found it! Luckily the "workaround" is fairly simple and it has little impact on our project as a whole.