nodejs · aduh95 · Dec 4, 2020 · Dec 5, 2020 · Dec 6, 2020 · Dec 6, 2020
diff --git a/lib/inspector.js b/lib/inspector.js
@@ -123,8 +123,7 @@ class Session extends EventEmitter {
       return;
     this[connectionSymbol].disconnect();
     this[connectionSymbol] = null;
-    const remainingCallbacks = this[messageCallbacksSymbol].values();
-    for (const callback of remainingCallbacks) {
+    for (const [, callback] of this[messageCallbacksSymbol]) {
       process.nextTick(callback, new ERR_INSPECTOR_CLOSED());
     }
     this[messageCallbacksSymbol].clear();

diff --git a/lib/internal/modules/cjs/loader.js b/lib/internal/modules/cjs/loader.js
@@ -1269,7 +1269,7 @@ Module._preloadModules = function(requests) {
 };
 
 Module.syncBuiltinESMExports = function syncBuiltinESMExports() {
-  for (const mod of NativeModule.map.values()) {
+  for (const [, mod] of NativeModule.map) {
     if (mod.canBeRequiredByUsers) {
       mod.syncExports();
     }

diff --git a/lib/internal/per_context/primordials.js b/lib/internal/per_context/primordials.js
@@ -72,9 +72,32 @@ function copyPrototype(src, dest, prefix) {
   }
 }
 
+const createSafeIterator = (factory, next) => {
+  class SafeIterator {
+    constructor(iterable) {
+      this._iterator = factory(iterable);
+    }
+    next() {
+      return next(this._iterator);
+    }
+  }
+  Object.setPrototypeOf(SafeIterator.prototype, null);
+  Object.freeze(SafeIterator.prototype);
+  Object.freeze(SafeIterator);
+  return SafeIterator;
+};
+
 function makeSafe(unsafe, safe) {
   copyProps(unsafe.prototype, safe.prototype);
   copyProps(unsafe, safe);
+  if (Symbol.iterator in unsafe.prototype) {
+    const createIterator = uncurryThis(unsafe.prototype[Symbol.iterator]);
+    const next = uncurryThis(createIterator(new unsafe()).next);
+    const SafeIterator = createSafeIterator(createIterator, next);
+    safe.prototype[Symbol.iterator] = function() {
+      return new SafeIterator(this);
+    };
+  }
   Object.setPrototypeOf(safe.prototype, null);
   Object.freeze(safe.prototype);
   Object.freeze(safe);

diff --git a/lib/internal/source_map/source_map_cache.js b/lib/internal/source_map/source_map_cache.js
@@ -7,17 +7,12 @@ const {
   ObjectKeys,
   ObjectGetOwnPropertyDescriptor,
   ObjectPrototypeHasOwnProperty,
-  Map,
-  MapPrototypeEntries,
   RegExpPrototypeTest,
   SafeMap,
   StringPrototypeMatch,
   StringPrototypeSplit,
-  uncurryThis,
 } = primordials;
 
-const MapIteratorNext = uncurryThis(MapPrototypeEntries(new Map()).next);
-
 function ObjectGetValueSafe(obj, key) {
   const desc = ObjectGetOwnPropertyDescriptor(obj, key);
   return ObjectPrototypeHasOwnProperty(desc, 'value') ? desc.value : undefined;
@@ -195,11 +190,7 @@ function rekeySourceMap(cjsModuleInstance, newInstance) {
 function sourceMapCacheToObject() {
   const obj = ObjectCreate(null);
 
-  const it = MapPrototypeEntries(esmSourceMapCache);
-  let entry;
-  while (!(entry = MapIteratorNext(it)).done) {
-    const k = entry.value[0];
-    const v = entry.value[1];
+  for (const [k, v] of esmSourceMapCache) {
     obj[k] = v;
   }