transcontextual safe type checks

lib/server.js

@@ -47,15 +47,15 @@ function mergeFunctionArgs (argv, start, end) {
   const handlers = []
 
   for (let i = start; i < end; i++) {
-    if (argv[i] instanceof Array) {
+    if (Array.isArray(argv[i])) {
       const arr = argv[i]
       for (let j = 0; j < arr.length; j++) {
-        if (!(arr[j] instanceof Function)) {
+        if (typeof arr[j] !== 'function') {
           throw new TypeError('Invalid argument type: ' + typeof (arr[j]))
         }
         handlers.push(arr[j])
       }
-    } else if (argv[i] instanceof Function) {
+    } else if (typeof argv[i] === 'function') {
       handlers.push(argv[i])
     } else {
       throw new TypeError('Invalid argument type: ' + typeof (argv[i]))

test/server.test.js

@@ -3,6 +3,7 @@
 const net = require('net')
 const tap = require('tap')
 const vasync = require('vasync')
+const vm = require('node:vm')
 const { getSock } = require('./utils')
 const ldap = require('../lib')
 
@@ -434,3 +435,16 @@ tap.test('multithreading support via hook', function (t) {
     })
   })
 })
+
+tap.test('cross-realm type checks', function (t) {
+  const server = ldap.createServer()
+  const ctx = vm.createContext({})
+  vm.runInContext(
+    'globalThis.search=function(){};\n' +
+    'globalThis.searches=[function(){}];'
+    , ctx)
+  server.search('', ctx.search)
+  server.search('', ctx.searches)
+  t.ok(server)
+  t.end()
+})