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False positive "no-unused-props" when using class with generic #1425

@echocrow

Description

@echocrow

Before You File a Bug Report Please Confirm You Have Done The Following...

  • I have tried restarting my IDE and the issue persists.
  • I have updated to the latest version of the packages.

What version of ESLint are you using?

9.39.1

What version of eslint-plugin-svelte are you using?

3.12.4

What did you do?

Configuration

Generated by sv

import { fileURLToPath } from 'node:url';
import { includeIgnoreFile } from '@eslint/compat';
import js from '@eslint/js';
import svelte from 'eslint-plugin-svelte';
import { defineConfig } from 'eslint/config';
import globals from 'globals';
import ts from 'typescript-eslint';
import svelteConfig from './svelte.config.js';

const gitignorePath = fileURLToPath(new URL('./.gitignore', import.meta.url));

export default defineConfig(
	includeIgnoreFile(gitignorePath),
	js.configs.recommended,
	...ts.configs.recommended,
	...svelte.configs.recommended,
	{
		languageOptions: {
			globals: { ...globals.browser, ...globals.node }
		},
		rules: { // typescript-eslint strongly recommend that you do not use the no-undef lint rule on TypeScript projects.
		// see: https://typescript-eslint.io/troubleshooting/faqs/eslint/#i-get-errors-from-the-no-undef-rule-about-global-variables-not-being-defined-even-though-there-are-no-typescript-errors
		"no-undef": 'off' }
	},
	{
		files: [
			'**/*.svelte',
			'**/*.svelte.ts',
			'**/*.svelte.js'
		],
		languageOptions: {
			parserOptions: {
				projectService: true,
				extraFileExtensions: ['.svelte'],
				parser: ts.parser,
				svelteConfig
			}
		}
	}
);
<script lang="ts" module>
export class FooController<T = unknown> {
  #foo: T

  constructor(foo: T) {
    this.#foo = foo
  }

  get foo() {
    return this.#foo
  }
}
</script>

<script lang="ts">
interface Props {
  ctrl: FooController
}
let {ctrl}: Props = $props()

// Mark `ctrl`/`ctrl.foo` as used
void ctrl.foo
</script>

What did you expect to happen?

Lint passes

What actually happened?

  19:5  error  '#foo' in 'ctrl' is an unused property  svelte/no-unused-props

Link to GitHub Repo with Minimal Reproducible Example

https://github.com/echocrow/eslint-plugin-svelte-repro--false-positive-unused-props

Additional comments

Error goes away when the class does not have any generics (i.e. in the above example, remove T = unknown and substitute T with e.g. unknown).

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