Update eslint to v9 format - flat config

Add tests to take a snapshot of the rules and check the configuration

Author: mderazon

index.js

@@ -1,47 +1,48 @@
-module.exports = {
-  'env': {
-    'es6': true,
-    'node': true,
+import js from "@eslint/js";
+import prettierConfig from "eslint-config-prettier";
+import * as typescriptEslintPlugin from "@typescript-eslint/eslint-plugin";
+import sonarjs from "eslint-plugin-sonarjs";
+
+export default [
+  js.configs.recommended,
+  sonarjs.configs.recommended,
+  prettierConfig,
+  {
+    files: ["**/*.{js,ts,jsx,tsx}"],
+    languageOptions: {
+      globals: {
+        Atomics: "readonly",
+        SharedArrayBuffer: "readonly",
+        es6: true,
+        node: true,
+      },
+      parser: typescriptEslintPlugin.parser,
+      parserOptions: {
+        ecmaVersion: 2018,
+        sourceType: "module",
+      },
+    },
+    plugins: {
+      "@typescript-eslint": typescriptEslintPlugin,
+      // sonarjs,
+    },
+    rules: {
+      "@typescript-eslint/no-use-before-define": "off",
+      "@typescript-eslint/no-inferrable-types": "off",
+      "@typescript-eslint/no-unused-vars": "error",
+      "@typescript-eslint/interface-name-prefix": "off",
+      "@typescript-eslint/consistent-type-assertions": [
+        "error",
+        { assertionStyle: "angle-bracket" },
+      ],
+      "@typescript-eslint/no-explicit-any": "off",
+      "@typescript-eslint/explicit-function-return-type": "off",
+    },
   },
-  'extends': [
-    'plugin:@typescript-eslint/recommended',
-    'plugin:sonarjs/recommended',
-    'prettier'
-  ],
-  'globals': {
-    'Atomics': 'readonly',
-    'SharedArrayBuffer': 'readonly',
+  {
+    files: ["**/*(specs|tests)/**", "**/*.spec.ts"],
+    rules: {
+      "@typescript-eslint/no-empty-function": "off",
+    },
   },
-  'parser': '@typescript-eslint/parser',
-  'parserOptions': {
-    'ecmaVersion': 2018,
-    'sourceType': 'module',
-  },
-  'plugins': [
-    '@typescript-eslint',
-    'sonarjs'
-  ],
-  'overrides': [
-    {
-      'files': ['**/*(specs|tests)/**', '**/*.spec.ts'],
-      'rules': {
-        '@typescript-eslint/no-empty-function': 'off',
-        'sonarjs/no-identical-functions': 'off',
-        'sonarjs/no-duplicate-string': 'off'
-      }
-    }
-  ],
-  'rules': {
-    '@typescript-eslint/no-use-before-define': 'off',
-    '@typescript-eslint/no-inferrable-types': 'off',
-    '@typescript-eslint/explicit-function-return-type': 'error',
-    '@typescript-eslint/no-unused-vars': 'error',
-    '@typescript-eslint/no-explicit-any': 'error',
-    '@typescript-eslint/interface-name-prefix': 'off',
-    '@typescript-eslint/consistent-type-assertions': ['error', {
-      assertionStyle: 'angle-bracket'
-    }],
-    '@typescript-eslint/no-explicit-any': 'off',
-    '@typescript-eslint/explicit-function-return-type': 'off'
-  }
-};
+];