From a940dbacbafe9c0345d7a90e1b2f51f277d79639 Mon Sep 17 00:00:00 2001
From: himself65 <himself65@outlook.com>
Date: Mon, 13 Apr 2020 18:01:47 +0800
Subject: [PATCH] vm: throw error when duplicated exportNames in
 SyntheticModule

Fixes: https://github.com/nodejs/node/issues/32806
---
 lib/internal/vm/module.js             | 12 +++++++++++-
 test/parallel/test-vm-module-basic.js | 14 ++++++++++++--
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/lib/internal/vm/module.js b/lib/internal/vm/module.js
index ed0dedd1e31b4f..992753ef680dbb 100644
--- a/lib/internal/vm/module.js
+++ b/lib/internal/vm/module.js
@@ -22,6 +22,7 @@ const {
 } = require('internal/util');
 const {
   ERR_INVALID_ARG_TYPE,
+  ERR_INVALID_ARG_VALUE,
   ERR_VM_MODULE_ALREADY_LINKED,
   ERR_VM_MODULE_DIFFERENT_CONTEXT,
   ERR_VM_MODULE_CANNOT_CREATE_CACHED_DATA,
@@ -379,8 +380,17 @@ class SyntheticModule extends Module {
   constructor(exportNames, evaluateCallback, options = {}) {
     if (!ArrayIsArray(exportNames) ||
       exportNames.some((e) => typeof e !== 'string')) {
-      throw new ERR_INVALID_ARG_TYPE('exportNames', 'Array of strings',
+      throw new ERR_INVALID_ARG_TYPE('exportNames',
+                                     'Array of unique strings',
                                      exportNames);
+    } else {
+      exportNames.forEach((name, i) => {
+        if (exportNames.indexOf(name, i + 1) !== -1) {
+          throw new ERR_INVALID_ARG_VALUE(`exportNames.${name}`,
+                                          name,
+                                          'is duplicated');
+        }
+      });
     }
     if (typeof evaluateCallback !== 'function') {
       throw new ERR_INVALID_ARG_TYPE('evaluateCallback', 'function',
diff --git a/test/parallel/test-vm-module-basic.js b/test/parallel/test-vm-module-basic.js
index 86e13f8b12bfa8..27b7f0476d502d 100644
--- a/test/parallel/test-vm-module-basic.js
+++ b/test/parallel/test-vm-module-basic.js
@@ -124,12 +124,22 @@ const util = require('util');
 // Check to throws invalid exportNames
 {
   assert.throws(() => new SyntheticModule(undefined, () => {}, {}), {
-    message: 'The "exportNames" argument must be an Array of strings.' +
-      ' Received undefined',
+    message: 'The "exportNames" argument must be an ' +
+        'Array of unique strings.' +
+        ' Received undefined',
     name: 'TypeError'
   });
 }
 
+// Check to throws duplicated exportNames
+// https://github.com/nodejs/node/issues/32806
+{
+  assert.throws(() => new SyntheticModule(['x', 'x'], () => {}, {}), {
+    message: 'The argument \'exportNames.x\' is duplicated. Received \'x\'',
+    name: 'TypeError',
+  });
+}
+
 // Check to throws invalid evaluateCallback
 {
   assert.throws(() => new SyntheticModule([], undefined, {}), {