False positive when accessing custom component props

[sveltejs]

False positive when accessing custom component props

[ota-meshi]

Thank you for posting the issue.

I already know the problem.
I'm doing an experiment to solve the problem.

https://github.com/ota-meshi/typescript-eslint-parser-for-extra-files

At least I have it working in my project.
https://github.com/ota-meshi/eslint-plugin-promise-playground/blob/4efb3d094056a45f87a86a4a2bc463d5ba9e9a9d/src/lib/eslint/ESLintEditor.svelte#L25-L29

If you are interested in it, please try it and give us feedback.
(I haven't tried it, but it might work in combination with eslint-plugin-svelte3.)

[ptrxyz]

Oh yes, that seems to do it. Thanks a bunch!

Any chance you also have an idea why x.doesNotExist does not raise an error? Obviously the prop does not exist yet neither ESlint nor Typescript seem to care. Did I miss something? Is there a rule for that?

[ota-meshi]

I think it's because all default imported classes from *.svelte files are of type SvelteComponentDev.

https://github.com/sveltejs/svelte/blob/master/src/runtime/ambient.ts

[ptrxyz]

I think it's because all default imported classes from *.svelte files are of type SvelteComponentDev.

https://github.com/sveltejs/svelte/blob/master/src/runtime/ambient.ts

Ok, thanks. I know, this is not in the scope of this issue, but I am really lost on this. Do you know/could point me to something on how to properly type the component to make TS raise an error when I try to access an undefined member?

[ota-meshi]

You can try the typescript-eslint-parser-for-extra-files.
https://github.com/ota-meshi/typescript-eslint-parser-for-extra-files

This is a project for passing proper types to @typescript-eslint for *.svelte etc.