From 79ffed7738f60bad18f2febc4d05433169742ec5 Mon Sep 17 00:00:00 2001
From: sjungwon03 <sjungwon03@gmail.com>
Date: Thu, 20 Aug 2026 10:43:34 +0900
Subject: [PATCH] module: derive builtinModules from enabled builtin set

Signed-off-by: sjungwon03 <sjungwon03@gmail.com>
---
 lib/internal/bootstrap/realm.js               | 11 +++++-
 lib/internal/modules/cjs/loader.js            | 15 +-------
 .../test-module-builtin-experimental.js       | 35 +++++++++++++++++++
 3 files changed, 46 insertions(+), 15 deletions(-)
 create mode 100644 test/parallel/test-module-builtin-experimental.js

diff --git a/lib/internal/bootstrap/realm.js b/lib/internal/bootstrap/realm.js
index 8a4d179806aa..4dfb39ae9568 100644
--- a/lib/internal/bootstrap/realm.js
+++ b/lib/internal/bootstrap/realm.js
@@ -334,7 +334,16 @@ class BuiltinModule {
 
   static getAllBuiltinModuleIds() {
     const allBuiltins = ArrayFrom(canBeRequiredByUsersWithoutSchemeList);
-    ArrayPrototypePushApply(allBuiltins, ArrayFrom(schemelessBlockList, (x) => `node:${x}`));
+    ArrayPrototypePushApply(
+      allBuiltins,
+      ArrayPrototypeMap(
+        ArrayPrototypeFilter(
+          ArrayFrom(schemelessBlockList),
+          (id) => canBeRequiredByUsersList.has(id),
+        ),
+        (id) => 'node:' + id,
+      ),
+    );
     return allBuiltins;
   }
 
diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
index bb466d0b68d5..6f62e9626ffe 100644
--- a/lib/internal/modules/cjs/loader.js
+++ b/lib/internal/modules/cjs/loader.js
@@ -492,20 +492,7 @@ Module.isBuiltin = BuiltinModule.isBuiltin;
 function initializeCJS() {
   // This need to be done at runtime in case --expose-internals is set.
 
-  let modules = Module.builtinModules = BuiltinModule.getAllBuiltinModuleIds();
-  if (!getOptionValue('--experimental-dtls')) {
-    modules = modules.filter((i) => i !== 'node:dtls');
-  }
-  if (!getOptionValue('--experimental-quic')) {
-    modules = modules.filter((i) => i !== 'node:quic');
-  }
-  if (!getOptionValue('--experimental-ffi')) {
-    modules = modules.filter((i) => i !== 'node:ffi');
-  }
-  if (!getOptionValue('--experimental-vfs')) {
-    modules = modules.filter((i) => i !== 'node:vfs');
-  }
-  Module.builtinModules = ObjectFreeze(modules);
+  Module.builtinModules = ObjectFreeze(BuiltinModule.getAllBuiltinModuleIds());
 
   initializeCjsConditions();
 
diff --git a/test/parallel/test-module-builtin-experimental.js b/test/parallel/test-module-builtin-experimental.js
new file mode 100644
index 000000000000..b8a5713a906d
--- /dev/null
+++ b/test/parallel/test-module-builtin-experimental.js
@@ -0,0 +1,35 @@
+'use strict';
+
+const common = require('../common');
+const { spawnSyncAndAssert } = require('../common/child_process');
+
+const experimentalBuiltins = [
+  ['dtls', '--experimental-dtls', common.hasDtls],
+  ['ffi', '--experimental-ffi', common.hasFFI],
+  ['quic', '--experimental-quic', common.hasQuic],
+  ['vfs', '--experimental-vfs', true],
+].filter(([, , available]) => available);
+
+for (const [id, flag] of experimentalBuiltins) {
+  const builtin = `node:${id}`;
+
+  spawnSyncAndAssert(process.execPath, [
+    '-e', `const m = require('node:module'); if (m.builtinModules.includes('${builtin}')) process.exit(1); try { require('${builtin}'); } catch (e) { if (e.code === 'ERR_UNKNOWN_BUILTIN_MODULE') process.exit(0); } process.exit(1);`,
+  ], { status: 0 });
+
+  spawnSyncAndAssert(process.execPath, [
+    flag,
+    '-e', `const m = require('node:module'); if (!m.builtinModules.includes('${builtin}')) process.exit(1); require('${builtin}');`,
+  ], { status: 0 });
+}
+
+const schemeOnlyBuiltins = ['node:test', 'node:sea'];
+if (common.hasSQLite) {
+  schemeOnlyBuiltins.push('node:sqlite');
+}
+
+for (const id of schemeOnlyBuiltins) {
+  spawnSyncAndAssert(process.execPath, [
+    '-e', `const m = require('node:module'); if (!m.builtinModules.includes('${id}')) process.exit(1); require('${id}');`,
+  ], { status: 0 });
+}