Enabling typescript-eslint type-checked rules causes files which use svelte-modals to have spurious lint errors.

[bmcbarron]

Describe the bug
When I migrated from svelte 4 to 5, I began to get eslint errors always involving any or "error typed value". After a lot of debugging, I discovered that this issues were limited to files that imported from 'svelte-modals'. I tried to understand why this was the case, but couldn't make progress.

Reproduction

1. Create a svelte project with eslint enabled using npx sv.
2. Utilize svelte-modals (svelte 5 api, not legacy).
3. Enable type-checked linting. The modified eslint.config.js will look similar to excerpt below.
4. Open .svelte or .ts files that import and utilize svelte-modals apis. There will be spurious eslint errors, but the code still works and typescript intellisense still understands the types.

import prettier from 'eslint-config-prettier';
import js from '@eslint/js';
import svelte from 'eslint-plugin-svelte';
import globals from 'globals';
import ts from 'typescript-eslint';

export default ts.config(
	js.configs.recommended,
	...ts.configs.recommendedTypeChecked,
	...svelte.configs['flat/recommended'],
	prettier,
	...svelte.configs['flat/prettier'],
	{
		languageOptions: {
			globals: {
				...globals.browser,
				...globals.node
			},
			parserOptions: {
				projectService: true,
				tsconfigRootDir: import.meta.dirname,
				extraFileExtensions: ['.svelte'],
			},
		}
	},
	{
		files: ['**/*.svelte'],

		languageOptions: {
			parserOptions: {
				parser: ts.parser
			}
		}
	},
	{
		ignores: ['build/', '.svelte-kit/', 'dist/']
	}
);

Additional context
Note that my repository is a monorepo, but based on my analysis it does not seem related to this issue.

Awesome tool btw! I've been using it for more than a year.

[mattjennings]

@bmcbarron thanks for the report! I'll take a look at this and see if I can figure it out.

[mattjennings]

@bmcbarron I created a new project and followed your steps but was not able to see this issue. I tried both your config and just adding ...ts.configs.recommendedTypeChecked to the config that comes out of the box with npx sv create for a typescript + eslint project.

I wonder if there's maybe multiple svelte versions installed in your monorepo, causing type conflicts? Would you be able to create a basic repro using your steps on a npx sv create project and share it here?

I did, however, notice that props aren't getting inferred properly from the component in modals.open(Modal, props) so I'll take a look at that.

[LoopControl]

@mattjennings Did you find a solution/workaround for the Typescript prop inferring issue?

The modal seems be working well after the upgrade to svelte 5 but i’m getting a typescript warning on every modals.open call:

Types of parameters 'props' and 'props' are incompatible.                                    
   Type 'ModalProps<any>' is missing the following properties from type '$$ComponentProps':   
     title, message [2345]

[mattjennings]

@LoopControl not yet. There's something up with Typescript not inferring the Props generic of modals.open properly because it's in an Omit<>. If I take out the Omit, it's inferred properly.

If anyone can figure it out I'd welcome a PR on it. Otherwise I'll try to circle back on this when I next have the free time.