From a59c0490cd9139c791887d2054b808b5c5794aed Mon Sep 17 00:00:00 2001
From: Som Samantray <92726151+SomSamantray@users.noreply.github.com>
Date: Wed, 12 Aug 2026 15:02:01 +0000
Subject: [PATCH] deps: honor --use-strict for wrapped CommonJS scripts

`node --use-strict script.js` did not apply strict mode to CommonJS
scripts. Parser::ParseWrapped(), used to parse the function V8
synthesizes for CommonJS module wrapping, hardcoded
LanguageMode::kSloppy instead of consulting the language mode already
configured on the ParseInfo. As a result the `--use-strict` CLI flag
had no effect on ordinary script execution, even though it worked
correctly from the REPL.

Pass `info->language_mode()` through to ParseFunctionLiteral() so the
wrapped function honors the language mode Node.js configured for the
parse, matching V8's behavior for other entry points.

Add regression coverage in test/parallel/test-cli-eval.js that runs a
script assigning to an undeclared variable with and without
`--use-strict`, asserting the ReferenceError is only thrown in the
latter case.

Fixes: https://github.com/nodejs/node/issues/30039
Signed-off-by: Som Samantray <92726151+SomSamantray@users.noreply.github.com>
---
 deps/v8/src/parsing/parser.cc  |  2 +-
 test/parallel/test-cli-eval.js | 25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/deps/v8/src/parsing/parser.cc b/deps/v8/src/parsing/parser.cc
index 509ca9322666..112bbc623d69 100644
--- a/deps/v8/src/parsing/parser.cc
+++ b/deps/v8/src/parsing/parser.cc
@@ -947,7 +947,7 @@ void Parser::ParseWrapped(Isolate* isolate, ParseInfo* info,
   FunctionLiteral* function_literal =
       ParseFunctionLiteral(function_name, location, kSkipFunctionNameCheck,
                            FunctionKind::kNormalFunction, kNoSourcePosition,
-                           FunctionSyntaxKind::kWrapped, LanguageMode::kSloppy,
+                           FunctionSyntaxKind::kWrapped, info->language_mode(),
                            arguments_for_wrapped_function);
 
   Statement* return_statement =
diff --git a/test/parallel/test-cli-eval.js b/test/parallel/test-cli-eval.js
index 5b090279621f..d0c0c9c16f62 100644
--- a/test/parallel/test-cli-eval.js
+++ b/test/parallel/test-cli-eval.js
@@ -30,8 +30,10 @@ if (module !== require.main) {
 const common = require('../common');
 const assert = require('assert');
 const child = require('child_process');
+const fs = require('fs');
 const path = require('path');
 const fixtures = require('../common/fixtures');
+const tmpdir = require('../common/tmpdir');
 
 if (process.argv.length > 2) {
   console.log(process.argv.slice(2).join(' '));
@@ -149,6 +151,29 @@ child.exec(...common.escapePOSIXShell`"${process.execPath}" --use-strict -p proc
              assert.strictEqual(stderr, '');
            }));
 
+// Regression test for https://github.com/nodejs/node/issues/30039.
+{
+  tmpdir.refresh();
+  const scriptPath = tmpdir.resolve('use-strict.js');
+  fs.writeFileSync(scriptPath, 'undeclared = 1;');
+
+  common.spawnPromisified(process.execPath, [scriptPath])
+    .then(common.mustCall(({ stdout, stderr, code, signal }) => {
+      assert.strictEqual(stdout, '');
+      assert.strictEqual(stderr, '');
+      assert.strictEqual(code, 0);
+      assert.strictEqual(signal, null);
+    }));
+
+  common.spawnPromisified(process.execPath, ['--use-strict', scriptPath])
+    .then(common.mustCall(({ stdout, stderr, code, signal }) => {
+      assert.strictEqual(stdout, '');
+      assert.match(stderr, /ReferenceError: undeclared is not defined/);
+      assert.strictEqual(code, 1);
+      assert.strictEqual(signal, null);
+    }));
+}
+
 // Regression test for https://github.com/nodejs/node/issues/3574.
 {
   const emptyFile = fixtures.path('empty.js');