src/third_party/mozjs-45/js/src/jit-test/tests/collections/Map-iterators-3.js

// A closed Map iterator does not visit new entries added after a clear().

load(libdir + "iteration.js");

var m = new Map();
var it = m[Symbol.iterator]();
assertIteratorDone(it, undefined);  // close the iterator
m.clear();
m.set("a", 1);
assertIteratorDone(it, undefined);  // iterator still closed