Reactive variable doesn't do type inference

[baseballyama]

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

• I'm using eslint-plugin-svelte. (*.svelte file linting does not work with the parser alone. You should also use eslint-plugin-svelte with it.)
• I'm sure the problem is a parser problem. (If you are not sure, search for the issue in eslint-plugin-svelte repo and open the issue in eslint-plugin-svelte repo if there is no solution.
• 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?

8.23.0

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

• svelte-eslint-parser@0.18.0
• eslint-plugin-svelte@2.7.0

What did you do?

Configuration

module.exports = {
  root: true,
  env: {
    es6: true,
    node: true,
  },
  globals: {
    window: true,
  },
  parser: '@typescript-eslint/parser',
  parserOptions: {
    sourceType: 'module',
    ecmaVersion: 2021,
    tsconfigRootDir: __dirname,
    project: ['./tsconfig.eslint.json'],
    extraFileExtensions: ['.svelte'],
  },
  plugins: ['@typescript-eslint'],
  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:@typescript-eslint/recommended-requiring-type-checking',
    'plugin:svelte/recommended',
  ],
  rules: {},
  overrides: [
    // see: https://github.com/typescript-eslint/typescript-eslint/blob/main/docs/linting/TROUBLESHOOTING.md#i-get-errors-from-the-no-undef-rule-about-global-variables-not-being-defined-even-though-there-are-no-typescript-errors
    {
      files: ['*.ts'],
      rules: {
        'no-undef': 'off',
      },
    },
    {
      files: ['**/*.svelte'],
      parser: 'svelte-eslint-parser',
      parserOptions: {
        parser: '@typescript-eslint/parser',
      },
      rules: {
        'no-undef': 'off',
      },
    },
  ],
};

<script lang="ts">
  let obj = {
    child: {
      title: "hello!",
    },
  };

  $: child = obj.child;
  $: title = child?.title ?? "Yo!";
</script>

{child}{title}

What did you expect to happen?

No ESLint error comes.

What actually happened?

/Users/baseballyama/Desktop/git/issue-eslint-plugin-svelte-1/src/Sample.svelte
  9:6   error  Unsafe assignment of an `any` value            @typescript-eslint/no-unsafe-assignment
  9:14  error  Unsafe member access .title on an `any` value  @typescript-eslint/no-unsafe-member-access

✖ 2 problems (2 errors, 0 warnings)

Link to Minimal Reproducible Example

https://github.com/baseballyama/issue-eslint-plugin-svelte-1

Additional comments

I think this is because TypeScript AST is inferred to any.
I'll try to fix this, but before that I would confirm how to fix it.
Do we need to type infer by inserting a dummy let child = obj.child; or something else?

[ota-meshi]

Thank you for posting this issue!

Do we need to type infer by inserting a dummy let child = obj.child; or something else?

I have opened a PR to modify to insert dummy code. #207

[baseballyama]

Wao! Thank you! Super fast!!!