switch to ESM and update config/test wiring

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

eslint.config.mjs

@@ -0,0 +1,52 @@
+import {defineConfig} from 'eslint/config';
+import js from '@eslint/js';
+import tseslint from '@typescript-eslint/eslint-plugin';
+import vitest from '@vitest/eslint-plugin';
+import globals from 'globals';
+import eslintConfigPrettier from 'eslint-config-prettier/flat';
+import eslintPluginPrettier from 'eslint-plugin-prettier';
+
+export default defineConfig([
+  {
+    ignores: ['.yarn/**/*', 'coverage/**/*', 'dist/**/*']
+  },
+  js.configs.recommended,
+  ...tseslint.configs['flat/recommended'],
+  eslintConfigPrettier,
+  {
+    languageOptions: {
+      globals: {
+        ...globals.node
+      }
+    }
+  },
+  {
+    files: ['__tests__/**'],
+    ...vitest.configs.recommended,
+    languageOptions: {
+      globals: {
+        ...globals.node,
+        ...vitest.environments.env.globals
+      }
+    },
+    rules: {
+      ...vitest.configs.recommended.rules,
+      'vitest/no-conditional-expect': 'error',
+      'vitest/no-disabled-tests': 0
+    }
+  },
+  {
+    plugins: {
+      prettier: eslintPluginPrettier
+    },
+    rules: {
+      'prettier/prettier': 'error',
+      '@typescript-eslint/no-require-imports': [
+        'error',
+        {
+          allowAsImport: true
+        }
+      ]
+    }
+  }
+]);