style: update to eslint v9

.lintstagedrc.json

@@ -1,4 +1,4 @@
 {
-  "*": ["prettier --check"],
-  "*.{js,ts}": ["eslint", "jest --bail --findRelatedTests --passWithNoTests"]
+  "*": ["prettier --check", "eslint"],
+  "*.{js,ts}": ["jest --bail --findRelatedTests --passWithNoTests"]
 }

eslint.config.js

@@ -0,0 +1,61 @@
+import eslint from '@eslint/js';
+import prettier from 'eslint-config-prettier';
+import importPlugin from 'eslint-plugin-import';
+import lit from 'eslint-plugin-lit';
+import wc from 'eslint-plugin-wc';
+import ymlPlugin from 'eslint-plugin-yml';
+import globals from 'globals';
+import ts from 'typescript-eslint';
+
+export default ts.config(
+  {
+    ignores: ['coverage/', 'docs/', 'demo/dist/', 'lib/', 'lit-redux-router.*'],
+  },
+  eslint.configs.all,
+  importPlugin.flatConfigs.recommended,
+  importPlugin.configs.typescript,
+  lit.configs['flat/recommended'],
+  wc.configs['flat/recommended'],
+  ...ymlPlugin.configs['flat/recommended'],
+  ...ymlPlugin.configs['flat/prettier'],
+  {
+    files: ['**/*.js', '**/*.ts'],
+    languageOptions: {
+      ecmaVersion: 'latest',
+      globals: { ...globals.node },
+      parserOptions: { project: 'tsconfig.json' },
+      sourceType: 'module',
+    },
+    rules: {
+      'import/no-unresolved': 'off',
+      'max-lines': ['error', { max: 133, skipBlankLines: true, skipComments: true }],
+      'max-lines-per-function': ['error', { max: 30, skipBlankLines: true, skipComments: true }],
+      'max-statements': ['error', { max: 35 }],
+      'no-ternary': 'off',
+      'one-var': 'off',
+      'sort-imports': 'off',
+    },
+    settings: { 'import/resolver': { typescript: {} } },
+  },
+  {
+    // eslint-disable-next-line import/no-named-as-default-member
+    extends: [...ts.configs.all],
+    files: ['**/*.ts'],
+    rules: {
+      '@typescript-eslint/class-methods-use-this': 'off',
+      // eslint-disable-next-line no-magic-numbers
+      '@typescript-eslint/no-magic-numbers': ['error', { ignore: [0, 1, 2] }],
+      '@typescript-eslint/prefer-readonly-parameter-types': 'off',
+    },
+  },
+  {
+    files: ['**/*.test.*'],
+    rules: {
+      '@typescript-eslint/no-floating-promises': 'off',
+      '@typescript-eslint/no-magic-numbers': 'off',
+      'max-lines': 'off',
+      'max-lines-per-function': 'off',
+    },
+  },
+  prettier,
+);

jest.config.js

@@ -1,5 +1,3 @@
-/* eslint-disable @typescript-eslint/naming-convention */
-
 export default {
   collectCoverageFrom: ['src/**/*.{j,t}s'],
   moduleNameMapper: { '^(\\.{1,2}/.*)\\.js$': '$1' },