From ef5444a2b373d0b75afbc276a6380b0cb72ed49e Mon Sep 17 00:00:00 2001
From: sangwook <bnbt3@naver.com>
Date: Wed, 14 Jan 2026 23:38:05 +0900
Subject: [PATCH 1/2] lib: fix TypeScript support check in jitless mode

WebAssembly is disabled when Node.js is run with --jitless. The
internal TypeScript stripper relies on WebAssembly, and previously
failed obscurely with a ReferenceError in this mode.

This commit adds an explicit check for WebAssembly support when
loading the TypeScript parser. If WebAssembly is unavailable,
it now throws a descriptive ERR_WEBASSEMBLY_NOT_SUPPORTED error.

Fixes: https://github.com/nodejs/node/issues/61353
---
 doc/api/errors.md                  |  8 ++++++++
 lib/internal/errors.js             |  3 +++
 lib/internal/util.js               |  4 ++++
 test/es-module/test-typescript.mjs | 11 +++++++++++
 4 files changed, 26 insertions(+)

diff --git a/doc/api/errors.md b/doc/api/errors.md
index a63fb28ab8933d..c059fac476e503 100644
--- a/doc/api/errors.md
+++ b/doc/api/errors.md
@@ -3350,6 +3350,14 @@ The WASI instance has already started.
 
 The WASI instance has not been started.
 
+<a id="ERR_WEBASSEMBLY_NOT_SUPPORTED"></a>
+
+### `ERR_WEBASSEMBLY_NOT_SUPPORTED`
+
+A feature requiring WebAssembly was used, but WebAssembly is not supported or
+has been disabled in the current environment (for example, when running with
+`--jitless`). The error message specifies which feature requires WebAssembly.
+
 <a id="ERR_WEBASSEMBLY_RESPONSE"></a>
 
 ### `ERR_WEBASSEMBLY_RESPONSE`
diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 5fa4437b09e556..7c4728627731fe 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1905,6 +1905,9 @@ E('ERR_VM_MODULE_NOT_MODULE',
   'Provided module is not an instance of Module', Error);
 E('ERR_VM_MODULE_STATUS', 'Module status %s', Error);
 E('ERR_WASI_ALREADY_STARTED', 'WASI instance has already started', Error);
+E('ERR_WEBASSEMBLY_NOT_SUPPORTED',
+  'WebAssembly is not supported in this environment, but is required for %s',
+  Error);
 E('ERR_WEBASSEMBLY_RESPONSE', 'WebAssembly response %s', TypeError);
 E('ERR_WORKER_INIT_FAILED', 'Worker initialization failure: %s', Error);
 E('ERR_WORKER_INVALID_EXEC_ARGV', (errors, msg = 'invalid execArgv flags') =>
diff --git a/lib/internal/util.js b/lib/internal/util.js
index 9739422d08284a..28bb83e558c426 100644
--- a/lib/internal/util.js
+++ b/lib/internal/util.js
@@ -46,6 +46,7 @@ const {
   SymbolPrototypeGetDescription,
   SymbolReplace,
   SymbolSplit,
+  globalThis,
 } = primordials;
 
 const {
@@ -53,6 +54,7 @@ const {
     ERR_NO_CRYPTO,
     ERR_NO_TYPESCRIPT,
     ERR_UNKNOWN_SIGNAL,
+    ERR_WEBASSEMBLY_NOT_SUPPORTED,
   },
   isErrorStackTraceLimitWritable,
   overrideStackTrace,
@@ -244,6 +246,8 @@ function assertCrypto() {
 function assertTypeScript() {
   if (noTypeScript)
     throw new ERR_NO_TYPESCRIPT();
+  if (globalThis.WebAssembly === undefined)
+    throw new ERR_WEBASSEMBLY_NOT_SUPPORTED('TypeScript');
 }
 
 /**
diff --git a/test/es-module/test-typescript.mjs b/test/es-module/test-typescript.mjs
index df25f60defd35b..2e98bc3f289d1e 100644
--- a/test/es-module/test-typescript.mjs
+++ b/test/es-module/test-typescript.mjs
@@ -342,3 +342,14 @@ test('check transform types warning', async () => {
   assert.match(result.stdout, /Hello, TypeScript!/);
   assert.strictEqual(result.code, 0);
 });
+
+test('expect error when executing a TypeScript file with --jitless', async () => {
+  const result = await spawnPromisified(process.execPath, [
+    '--jitless',
+    fixtures.path('typescript/ts/test-typescript.ts'),
+  ]);
+
+  assert.match(result.stderr, /ERR_WEBASSEMBLY_NOT_SUPPORTED/);
+  assert.match(result.stderr, /WebAssembly is not supported in this environment, but is required for TypeScript/);
+  assert.strictEqual(result.code, 1);
+});

From f689364dd97bf0b47f7b39cf35d4857ed03152a1 Mon Sep 17 00:00:00 2001
From: sangwook <73056306+Han5991@users.noreply.github.com>
Date: Thu, 15 Jan 2026 18:59:49 +0900
Subject: [PATCH 2/2] doc: refine WebAssembly error documentation

Co-authored-by: Marco Ippolito <marcoippolito54@gmail.com>
---
 doc/api/errors.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/api/errors.md b/doc/api/errors.md
index c059fac476e503..b55f659c39ed94 100644
--- a/doc/api/errors.md
+++ b/doc/api/errors.md
@@ -3356,7 +3356,7 @@ The WASI instance has not been started.
 
 A feature requiring WebAssembly was used, but WebAssembly is not supported or
 has been disabled in the current environment (for example, when running with
-`--jitless`). The error message specifies which feature requires WebAssembly.
+`--jitless`).
 
 <a id="ERR_WEBASSEMBLY_RESPONSE"></a>