module: add isBuiltin method

doc/api/module.md

@@ -62,6 +62,22 @@ const require = createRequire(import.meta.url);
 const siblingModule = require('./sibling-module');
 ```
 
+### `module.isBuiltin(moduleName)`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* `moduleName`{string} name of the module
+* Returns:{boolean} returns true if the module is builtin else returns false
+
+```mjs
+import{isBuiltin } from 'node:module'
+isBuiltin('node:fs'); // true
+isBuiltin('fs'); // true
+isBuiltin('wss'); // false
+```
+
 ### `module.syncBuiltinESMExports()`
 
 <!-- YAML

lib/internal/modules/cjs/loader.js

@@ -33,6 +33,7 @@ const{
  ArrayPrototypeSplice,
  ArrayPrototypeUnshift,
  ArrayPrototypeUnshiftApply,
+ ArrayPrototypeFlatMap,
  Boolean,
  Error,
  JSONParse,
@@ -51,6 +52,7 @@ const{
  RegExpPrototypeExec,
  RegExpPrototypeTest,
  SafeMap,
+ SafeSet,
  SafeWeakMap,
  String,
  StringPrototypeCharAt,
@@ -188,6 +190,11 @@ for (const{0: id, 1: mod } of NativeModule.map){
  }
 }
 
+const allBuiltins = new SafeSet(
+ ArrayPrototypeFlatMap(builtinModules, (bm) => [bm, `node:${bm}`])
+);
+NativeModule.getSchemeOnlyModuleNames().forEach((builtin) => allBuiltins.add(`node:${builtin}`));
+
 ObjectFreeze(builtinModules);
 Module.builtinModules = builtinModules;
 
@@ -1293,5 +1300,9 @@ Module.syncBuiltinESMExports = function syncBuiltinESMExports(){
  }
 };
 
+Module.isBuiltin = function isBuiltin(moduleName){
+ return allBuiltins.has(moduleName);
+};
+
 // Backwards compatibility
 Module.Module = Module;

test/parallel/test-module-isBuiltin.js

@@ -0,0 +1,16 @@
+'use strict'
+require('../common');
+const assert = require('assert');
+const{isBuiltin } = require('module');
+
+// Includes modules in lib/ (even deprecated ones)
+assert(isBuiltin('http'));
+assert(isBuiltin('sys'));
+assert(isBuiltin('node:fs'));
+assert(isBuiltin('node:test'));
+
+// Does not include internal modules
+assert(!isBuiltin('internal/errors'));
+assert(!isBuiltin('test'));
+assert(!isBuiltin(''));
+assert(!isBuiltin(undefined));