lib: reset RegExp statics before running user code

Fixes: #43740

lib/internal/main/run_main_module.js

@@ -1,5 +1,7 @@
 'use strict';
 
+const { RegExpPrototypeExec } = primordials;
+
 const {
   prepareMainThreadExecution
 } = require('internal/bootstrap/pre_execution');
@@ -8,6 +10,9 @@ prepareMainThreadExecution(true);
 
 markBootstrapComplete();
 
+// Necessary to reset RegExp statics before user code runs.
+RegExpPrototypeExec(/^/, '');
+
 // Note: this loads the module through the ESM loader if the module is
 // determined to be an ES module. This hangs from the CJS module loader
 // because we currently allow monkey-patching of the module loaders

lib/internal/modules/esm/translators.js

@@ -11,7 +11,7 @@ const {
   SafeArrayIterator,
   SafeMap,
   SafeSet,
-  StringPrototypeReplace,
+  StringPrototypeReplaceAll,
   StringPrototypeSlice,
   StringPrototypeStartsWith,
   SyntaxErrorPrototype,
@@ -144,14 +144,13 @@ function enrichCJSError(err, content, filename) {
 
 // Strategy for loading a node-style CommonJS module
 const isWindows = process.platform === 'win32';
-const winSepRegEx = /\//g;
 translators.set('commonjs', async function commonjsStrategy(url, source,
                                                             isMain) {
   debug(`Translating CJSModule ${url}`);
 
   let filename = internalURLModule.fileURLToPath(new URL(url));
   if (isWindows)
-    filename = StringPrototypeReplace(filename, winSepRegEx, '\\');
+    filename = StringPrototypeReplaceAll(filename, '/', '\\');
 
   if (!cjsParse) await initCJSParse();
   const { module, exportNames } = cjsPreparseModuleExports(filename);
@@ -274,7 +273,7 @@ translators.set('json', async function jsonStrategy(url, source) {
   let module;
   if (pathname) {
     modulePath = isWindows ?
-      StringPrototypeReplace(pathname, winSepRegEx, '\\') : pathname;
+      StringPrototypeReplaceAll(pathname, '/', '\\') : pathname;
     module = CJSModule._cache[modulePath];
     if (module && module.loaded) {
       const exports = module.exports;

lib/internal/process/execution.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const {
+  RegExpPrototypeExec,
   globalThis,
 } = primordials;
 
@@ -45,6 +46,7 @@ function evalModule(source, print) {
   }
   const { loadESM } = require('internal/process/esm_loader');
   const { handleMainPromise } = require('internal/modules/run_main');
+  RegExpPrototypeExec(/^/, ''); // Necessary to reset RegExp statics before user code runs.
   return handleMainPromise(loadESM((loader) => loader.eval(source)));
 }
 
@@ -72,6 +74,7 @@ function evalScript(name, body, breakFirstLine, print) {
     return (main) => main();
   `;
   globalThis.__filename = name;
+  RegExpPrototypeExec(/^/, ''); // Necessary to reset RegExp statics before user code runs.
   const result = module._compile(script, `${name}-wrapper`)(() =>
     require('vm').runInThisContext(body, {
       filename: name,

test/parallel/test-startup-empty-regexp-statics.js

@@ -0,0 +1,68 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('node:assert');
+const { spawnSync, spawn } = require('node:child_process');
+
+assert.strictEqual(RegExp.$_, '');
+assert.strictEqual(RegExp.$0, undefined);
+assert.strictEqual(RegExp.$1, '');
+assert.strictEqual(RegExp.$2, '');
+assert.strictEqual(RegExp.$3, '');
+assert.strictEqual(RegExp.$4, '');
+assert.strictEqual(RegExp.$5, '');
+assert.strictEqual(RegExp.$6, '');
+assert.strictEqual(RegExp.$7, '');
+assert.strictEqual(RegExp.$8, '');
+assert.strictEqual(RegExp.$9, '');
+assert.strictEqual(RegExp.input, '');
+assert.strictEqual(RegExp.lastMatch, '');
+assert.strictEqual(RegExp.lastParen, '');
+assert.strictEqual(RegExp.leftContext, '');
+assert.strictEqual(RegExp.rightContext, '');
+assert.strictEqual(RegExp['$&'], '');
+assert.strictEqual(RegExp['$`'], '');
+assert.strictEqual(RegExp['$+'], '');
+assert.strictEqual(RegExp["$'"], '');
+
+const allRegExpStatics =
+    'RegExp.$_ + RegExp["$&"] + RegExp["$`"] + RegExp["$+"] + RegExp["$\'"] + ' +
+    'RegExp.input + RegExp.lastMatch + RegExp.lastParen + ' +
+    'RegExp.leftContext + RegExp.rightContext + ' +
+    Array.from({ length: 10 }, (_, i) => `RegExp.$${i}`).join(' + ');
+
+{
+  const child = spawnSync(process.execPath,
+                          [ '-p', allRegExpStatics ],
+                          { stdio: ['inherit', 'pipe', 'inherit'] });
+  assert.match(child.stdout.toString(), /^undefined\r?\n$/);
+  assert.strictEqual(child.status, 0);
+  assert.strictEqual(child.signal, null);
+}
+
+{
+  const child = spawnSync(process.execPath,
+                          [ '-e', `console.log(${allRegExpStatics})`, '--input-type=module' ],
+                          { stdio: ['inherit', 'pipe', 'inherit'] });
+  assert.match(child.stdout.toString(), /^undefined\r?\n$/);
+  assert.strictEqual(child.status, 0);
+  assert.strictEqual(child.signal, null);
+}
+
+{
+  const child = spawn(process.execPath, [], { stdio: ['pipe', 'pipe', 'inherit'], encoding: 'utf8' });
+
+  let stdout = '';
+  child.stdout.on('data', (chunk) => {
+    stdout += chunk;
+  });
+
+  child.on('exit', common.mustCall((status, signal) => {
+    assert.match(stdout, /^undefined\r?\n$/);
+    assert.strictEqual(status, 0);
+    assert.strictEqual(signal, null);
+  }));
+  child.on('error', common.mustNotCall());
+
+  child.stdin.end(`console.log(${allRegExpStatics});\n`);
+}

test/parallel/test-startup-empty-regexp-statics.mjs

@@ -0,0 +1,30 @@
+// We must load the CJS version here because the ESM wrapper call `hasIPv6`
+// which compiles a RegEx.
+// eslint-disable-next-line node-core/require-common-first
+import common from '../common/index.js';
+
+import assert from 'node:assert';
+
+// TODO(aduh95): make this test pass on Windows.
+if (common.isWindows) common.skip('Test fails on Windows');
+
+assert.strictEqual(RegExp.$_, '');
+assert.strictEqual(RegExp.$0, undefined);
+assert.strictEqual(RegExp.$1, '');
+assert.strictEqual(RegExp.$2, '');
+assert.strictEqual(RegExp.$3, '');
+assert.strictEqual(RegExp.$4, '');
+assert.strictEqual(RegExp.$5, '');
+assert.strictEqual(RegExp.$6, '');
+assert.strictEqual(RegExp.$7, '');
+assert.strictEqual(RegExp.$8, '');
+assert.strictEqual(RegExp.$9, '');
+assert.strictEqual(RegExp.input, '');
+assert.strictEqual(RegExp.lastMatch, '');
+assert.strictEqual(RegExp.lastParen, '');
+assert.strictEqual(RegExp.leftContext, '');
+assert.strictEqual(RegExp.rightContext, '');
+assert.strictEqual(RegExp['$&'], '');
+assert.strictEqual(RegExp['$`'], '');
+assert.strictEqual(RegExp['$+'], '');
+assert.strictEqual(RegExp["$'"], '');