eslint.config.mjs

import typescriptEslint from '@typescript-eslint/eslint-plugin';
import tsParser from '@typescript-eslint/parser';
import path from 'node:path';
import {fileURLToPath} from 'node:url';
import js from '@eslint/js';
import {FlatCompat} from '@eslint/eslintrc';
import {configs as litPluginConfigs} from 'eslint-plugin-lit';
import {configs as wcPluginConfigs} from 'eslint-plugin-wc';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const compat = new FlatCompat({
  baseDirectory: __dirname,
  recommendedConfig: js.configs.recommended,
  allConfig: js.configs.all,
});

export default [
  litPluginConfigs['flat/recommended'],
  wcPluginConfigs['flat/recommended'],
  {
    ignores: ['dist/', 'docs-src/', '**/*.test.ts'],
  },
  ...compat.extends(
    'eslint:recommended',
    'plugin:@typescript-eslint/eslint-recommended',
    'plugin:@typescript-eslint/recommended'
  ),
  {
    plugins: {
      '@typescript-eslint': typescriptEslint,
    },

    languageOptions: {
      parser: tsParser,
      ecmaVersion: 2020,
      sourceType: 'module',
    },

    rules: {
      'no-unexpected-multiline': 'off',
      '@typescript-eslint/indent': 'off',
      '@typescript-eslint/explicit-function-return-type': 'off',
      '@typescript-eslint/no-non-null-assertion': 'off',
      '@typescript-eslint/no-use-before-define': 'off',
      '@typescript-eslint/no-unused-vars': 'off',
      'lit/quoted-expressions': 'error',
    },

    settings: {
      wc: {
        elementBaseClasses: ['LitElement'], // Recognize `LitElement` as a Custom Element base class
      },
    },
  },
];