lib: fix TypeScript support check in jitless mode

Han5991 · aduh95 · commit f55a5fea00f7 · 2026-01-20T14:36:02.000+01:00
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: #61353 PR-URL: #61382 Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
diff --git 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
@@ -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
@@ -46,13 +46,15 @@ const {
   SymbolPrototypeGetDescription,
   SymbolReplace,
   SymbolSplit,
+  globalThis,
 } = primordials;
 
 const {
   codes: {
     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
@@ -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);
+});
