1 files changed, 14 insertions, 1 deletions
diff --git a/tests/unit_node/module_test.ts b/tests/unit_node/module_test.ts
index 6935b080a..eb1825890 100644
--- a/tests/unit_node/module_test.ts
+++ b/tests/unit_node/module_test.ts
@@ -1,6 +1,6 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
 
-import { createRequire, Module } from "node:module";
+import { createRequire, isBuiltin, Module } from "node:module";
 import { assert, assertEquals } from "@std/assert/mod.ts";
 import process from "node:process";
 import * as path from "node:path";
@@ -70,3 +70,16 @@ Deno.test("Built-in Node modules have `node:` prefix", () => {
 
   assert(thrown);
 });
+
+Deno.test("[node/module isBuiltin] recognizes node builtins", () => {
+  assert(isBuiltin("node:fs"));
+  assert(isBuiltin("node:test"));
+  assert(isBuiltin("fs"));
+  assert(isBuiltin("buffer"));
+
+  assert(!isBuiltin("internal/errors"));
+  assert(!isBuiltin("test"));
+  assert(!isBuiltin(""));
+  // deno-lint-ignore no-explicit-any
+  assert(!isBuiltin(undefined as any));
+});