chore: enforce code formatting with @stylistic, mirroring nodejs/node

eslint.config.js

@@ -1,48 +1,134 @@
-import { defineConfig, globalIgnores } from "eslint/config";
-import globals from "globals";
+import { defineConfig, globalIgnores } from 'eslint/config';
+import globals from 'globals';
 import eslint from '@eslint/js';
 import tseslint from 'typescript-eslint';
+import stylistic from '@stylistic/eslint-plugin';
 
 export default defineConfig([
-  globalIgnores(["**/CMakeFiles/**"]),
+  globalIgnores(['**/CMakeFiles/**', 'build/**']),
   eslint.configs.recommended,
   tseslint.configs.recommended,
+  // Formatting rules mirrored from nodejs/node's eslint.config.mjs.
+  // nodejs/node uses the JS-only @stylistic/eslint-plugin-js; this repo has
+  // TypeScript, so we use the unified @stylistic/eslint-plugin (same rules,
+  // JS + TS aware). Keep this block in sync with upstream when it changes.
+  {
+    files: ['**/*.{js,mjs,ts}'],
+    plugins: { '@stylistic': stylistic },
+    rules: {
+      '@stylistic/arrow-parens': 'error',
+      '@stylistic/arrow-spacing': 'error',
+      '@stylistic/block-spacing': 'error',
+      '@stylistic/brace-style': ['error', '1tbs', { allowSingleLine: true }],
+      '@stylistic/comma-dangle': ['error', 'always-multiline'],
+      '@stylistic/comma-spacing': 'error',
+      '@stylistic/comma-style': 'error',
+      '@stylistic/computed-property-spacing': 'error',
+      '@stylistic/dot-location': ['error', 'property'],
+      '@stylistic/eol-last': 'error',
+      '@stylistic/function-call-spacing': 'error',
+      '@stylistic/indent': ['error', 2, {
+        ArrayExpression: 'first',
+        CallExpression: { arguments: 'first' },
+        FunctionDeclaration: { parameters: 'first' },
+        FunctionExpression: { parameters: 'first' },
+        MemberExpression: 'off',
+        ObjectExpression: 'first',
+        SwitchCase: 1,
+        assignmentOperator: 'off',
+      }],
+      '@stylistic/key-spacing': 'error',
+      '@stylistic/keyword-spacing': 'error',
+      '@stylistic/linebreak-style': 'error',
+      '@stylistic/max-len': ['error', {
+        code: 120,
+        ignorePattern: '^// Flags:',
+        ignoreRegExpLiterals: true,
+        ignoreTemplateLiterals: true,
+        ignoreUrls: true,
+        tabWidth: 2,
+      }],
+      '@stylistic/new-parens': 'error',
+      '@stylistic/no-confusing-arrow': 'error',
+      '@stylistic/no-extra-parens': ['error', 'functions'],
+      '@stylistic/no-multi-spaces': ['error', { ignoreEOLComments: true }],
+      '@stylistic/no-multiple-empty-lines': ['error', { max: 2, maxEOF: 0, maxBOF: 0 }],
+      '@stylistic/no-tabs': 'error',
+      '@stylistic/no-trailing-spaces': 'error',
+      '@stylistic/no-whitespace-before-property': 'error',
+      '@stylistic/object-curly-newline': 'error',
+      '@stylistic/object-curly-spacing': ['error', 'always'],
+      '@stylistic/one-var-declaration-per-line': 'error',
+      '@stylistic/operator-linebreak': ['error', 'after'],
+      '@stylistic/padding-line-between-statements': [
+        'error',
+        { blankLine: 'always', prev: 'function', next: 'function' },
+      ],
+      '@stylistic/quotes': ['error', 'single', { avoidEscape: true, allowTemplateLiterals: 'always' }],
+      '@stylistic/quote-props': ['error', 'consistent'],
+      '@stylistic/rest-spread-spacing': 'error',
+      '@stylistic/semi': 'error',
+      '@stylistic/semi-spacing': 'error',
+      '@stylistic/space-before-blocks': ['error', 'always'],
+      '@stylistic/space-before-function-paren': ['error', {
+        anonymous: 'never',
+        named: 'never',
+        asyncArrow: 'always',
+      }],
+      '@stylistic/space-in-parens': 'error',
+      '@stylistic/space-infix-ops': 'error',
+      '@stylistic/space-unary-ops': 'error',
+      '@stylistic/spaced-comment': ['error', 'always', {
+        block: { balanced: true },
+        exceptions: ['-'],
+      }],
+      '@stylistic/template-curly-spacing': 'error',
+    },
+  },
   {
     files: [
-      "tests/**/*.js",
+      'tests/**/*.js',
     ],
     languageOptions: {
       // Only allow ECMAScript built-ins and CTS harness globals.
       // This causes no-undef to flag any runtime-specific API (setTimeout, process, Buffer, etc.).
       globals: {
         ...globals.es2025,
         // CTS harness globals
-        assert: "readonly",
-        loadAddon: "readonly",
-        mustCall: "readonly",
-        mustNotCall: "readonly",
-        gc: "readonly",
-        gcUntil: "readonly",
-        experimentalFeatures: "readonly",
-        napiVersion: "readonly",
-        skipTest: "readonly",
+        assert: 'readonly',
+        loadAddon: 'readonly',
+        mustCall: 'readonly',
+        mustNotCall: 'readonly',
+        gc: 'readonly',
+        gcUntil: 'readonly',
+        experimentalFeatures: 'readonly',
+        onUncaughtException: 'readonly',
+        napiVersion: 'readonly',
+        skipTest: 'readonly',
       },
     },
     rules: {
-      "no-undef": "error",
-      "no-restricted-imports": ["error", {
-        patterns: ["*"],
+      'no-undef': 'error',
+      'no-restricted-imports': ['error', {
+        patterns: ['*'],
       }],
-      "no-restricted-syntax": ["error",
-        { selector: "MemberExpression[object.name='globalThis']", message: "Avoid globalThis access in test files — use CTS harness globals instead" },
-        { selector: "MemberExpression[object.name='global']", message: "Avoid global access in test files — use CTS harness globals instead" }
+      'no-restricted-syntax': [
+        'error',
+        {
+          selector: "MemberExpression[object.name='globalThis']",
+          message: 'Avoid globalThis access in test files — use CTS harness globals instead',
+        },
+        {
+          selector: "MemberExpression[object.name='global']",
+          message: 'Avoid global access in test files — use CTS harness globals instead',
+        },
       ],
     },
   },
   {
     files: [
-      "implementors/**/*.{js,ts}",
-      "scripts/**/*.{js,mjs}",
+      'implementors/**/*.{js,ts}',
+      'scripts/**/*.{js,mjs}',
     ],
     languageOptions: {
       globals: {

implementors/node/assert.js

@@ -5,7 +5,7 @@ import {
   deepStrictEqual,
   throws,
   match,
-} from "node:assert/strict";
+} from 'node:assert/strict';
 
 const assert = Object.assign((value, message) => ok(value, message), {
   ok: (value, message) => ok(value, message),

implementors/node/features.js

@@ -2,7 +2,7 @@
 // Each key corresponds to a NODE_API_EXPERIMENTAL_HAS_* compile-time macro.
 // Other implementors should set unsupported features to false or omit them.
 
-const [major, minor, patch] = process.version.slice(1).split(".").map(Number);
+const [major, minor, patch] = process.version.slice(1).split('.').map(Number);
 
 globalThis.experimentalFeatures = {
   // node_api_is_sharedarraybuffer and node_api_create_sharedarraybuffer were

implementors/node/gc.js

@@ -1,9 +1,9 @@
 // Capture the engine-provided gc (Node exposes it under --expose-gc) before
 // we overwrite globalThis.gc with the harness wrapper below.
 const engineGc = globalThis.gc;
-if (typeof engineGc !== "function") {
+if (typeof engineGc !== 'function') {
   throw new Error(
-    "Node harness expects globalThis.gc to be available (run with --expose-gc)",
+    'Node harness expects globalThis.gc to be available (run with --expose-gc)',
   );
 }
 

implementors/node/load-addon.js

@@ -1,13 +1,13 @@
-import assert from "node:assert/strict";
-import { dlopen } from "node:process";
-import { constants } from "node:os";
-import path from "node:path";
-import fs from "node:fs";
+import assert from 'node:assert/strict';
+import { dlopen } from 'node:process';
+import { constants } from 'node:os';
+import path from 'node:path';
+import fs from 'node:fs';
 
 const loadAddon = (addonFileName) => {
-  assert(typeof addonFileName === "string", "Expected a string as addon filename");
-  assert(!addonFileName.endsWith(".node"), "Expected addon filename without the .node extension");
-  const addonPath = path.join(process.cwd(), addonFileName + ".node");
+  assert(typeof addonFileName === 'string', 'Expected a string as addon filename');
+  assert(!addonFileName.endsWith('.node'), 'Expected addon filename without the .node extension');
+  const addonPath = path.join(process.cwd(), addonFileName + '.node');
   assert(fs.existsSync(addonPath), `Expected ${addonPath} to exist - did you build the addons?`);
   const addon = { exports: {} };
   dlopen(addon, addonPath, constants.dlopen.RTLD_NOW);

implementors/node/must-call.js

@@ -13,7 +13,7 @@ const mustCall = (fn, exact = 1) => {
   const entry = {
     exact,
     actual: 0,
-    name: fn?.name || "<anonymous>",
+    name: fn?.name || '<anonymous>',
     error: new Error(), // capture call-site stack
   };
   pendingCalls.push(entry);
@@ -28,11 +28,11 @@ const mustCall = (fn, exact = 1) => {
  */
 const mustNotCall = (msg) => {
   return () => {
-    throw new Error(msg || "mustNotCall function was called");
+    throw new Error(msg || 'mustNotCall function was called');
   };
 };
 
-process.on("exit", () => {
+process.on('exit', () => {
   for (const entry of pendingCalls) {
     if (entry.actual !== entry.exact) {
       entry.error.message =

implementors/node/run-tests.ts

@@ -1,13 +1,13 @@
-import path from "node:path";
-import { test } from "node:test";
+import path from 'node:path';
+import { test } from 'node:test';
 
-import { listDirectoryEntries, runFileInSubprocess } from "./tests.ts";
+import { listDirectoryEntries, runFileInSubprocess } from './tests.ts';
 
-const ROOT_PATH = path.resolve(import.meta.dirname, "..", "..");
-const TESTS_ROOT_PATH = path.join(ROOT_PATH, "tests");
+const ROOT_PATH = path.resolve(import.meta.dirname, '..', '..');
+const TESTS_ROOT_PATH = path.join(ROOT_PATH, 'tests');
 
 function populateSuite(
-  dir: string
+  dir: string,
 ) {
   const { directories, files } = listDirectoryEntries(dir);
 
@@ -20,6 +20,6 @@ function populateSuite(
   }
 }
 
-populateSuite(path.join(TESTS_ROOT_PATH, "harness"));
-populateSuite(path.join(TESTS_ROOT_PATH, "js-native-api"));
-populateSuite(path.join(TESTS_ROOT_PATH, "node-api"));
+populateSuite(path.join(TESTS_ROOT_PATH, 'harness'));
+populateSuite(path.join(TESTS_ROOT_PATH, 'js-native-api'));
+populateSuite(path.join(TESTS_ROOT_PATH, 'node-api'));