.eslintrc.js

// .eslintrc.js

module.exports = {
    parser: '@typescript-eslint/parser',
    extends: [
        'eslint:recommended',
        'plugin:@typescript-eslint/recommended',
        'plugin:@typescript-eslint/recommended-requiring-type-checking'
    ],
    parserOptions: {
        ecmaVersion: 2020,
        sourceType: 'module',
        tsconfigRootDir: __dirname,
        project: ['./tsconfig.json'],
        extraFileExtensions: ['.svelte']
    },
    env: {
        es6: true,
        browser: true
    },
    overrides: [
        {
            files: ['*.svelte'],
            processor: 'svelte3/svelte3'
        }
    ],
    settings: {
        'svelte3/typescript': require('typescript'),
        // ignore style tags in Svelte because of Tailwind CSS
        // See https://github.com/sveltejs/eslint-plugin-svelte3/issues/70
        'svelte3/ignore-styles': () => true
    },
    plugins: ['svelte3', '@typescript-eslint'],
    ignorePatterns: ['node_modules']
}