for-of should throw if result object is not an object

test/mjsunit/es6/iteration-semantics.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 182 matching lines @@
                   results([{ done: false },
                            { value: 1, done: false },
                            // A missing "done" is the same as undefined, which
                            // is false.
                            { value: 2 },
                            // Not done.
                            { value: 3, done: 0 },
                            // Done.
                            { value: 4, done: 42 }])));
 // Results that are not objects.
-assertEquals([undefined, undefined, undefined],
-             fold(append, [],
-                  results([10, "foo", /qux/, { value: 37, done: true }])));
+assertThrows(function() {
+  assertEquals([undefined, undefined, undefined],
+               fold(append, [],
+                    results([10, "foo", /qux/, { value: 37, done: true }])));
+}, TypeError);
 // Getters (shudder).
 assertEquals([1, 2],
              fold(append, [],
                   results([one_time_getter({ value: 1 }, 'done', false),
                            one_time_getter({ done: false }, 'value', 2),
                            { value: 37, done: true },
                            never_getter(never_getter({}, 'done'), 'value')])));
 
 // Unlike the case with for-in, null and undefined cause an error.
 assertThrows('fold(sum, 0, unreachable(null))', TypeError);
@@ skipping 111 matching lines @@
       if (name == 'next' && n-- < 0) throw "unreachable";
       return iterator[name];
     },
     // Needed for integers_until(10)'s this.n++.
     set: function(receiver, name, val) {
       return iterator[name] = val;
     }
   }));
 }
 assertEquals(45, fold(sum, 0, poison_proxy_after(integers_until(10), 10)));
+
+
+function test_iterator_result_object_non_object(value, descr) {
+  var arr = [];
+  var ex;
+  var message = 'Iterator result ' + (descr || value) + ' is not an object';
+  try {
+    fold(append, arr,
+         results([{value: 1}, {}, value, {value: 2}, {done: true}]));
+  } catch (e) {
+    ex = e;
+  }
+  assertInstanceof(ex, TypeError);
+  assertEquals(message, ex.message);
+  assertArrayEquals([1, undefined], arr);
+}
+test_iterator_result_object_non_object(null);
+test_iterator_result_object_non_object(undefined);
+test_iterator_result_object_non_object(42);
+test_iterator_result_object_non_object('abc');
+test_iterator_result_object_non_object(false);
+test_iterator_result_object_non_object(Symbol('x'), 'Symbol(x)');