1 files changed, 39 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/collections/iterator-proto-surfaces.js b/js/src/jit-test/tests/collections/iterator-proto-surfaces.js
new file mode 100644
index 0000000000..e39ae777fb
--- /dev/null
+++ b/js/src/jit-test/tests/collections/iterator-proto-surfaces.js
@@ -0,0 +1,39 @@
+// Iterator prototype surfaces.
+
+load(libdir + "asserts.js");
+load(libdir + "iteration.js");
+
+var iterProto = null;
+
+function test(constructor) {
+    var iter = new constructor()[Symbol.iterator]();
+    assertDeepEq(Reflect.ownKeys(iter), []);
+
+    // Iterator prototypes only have a .next and @@toStringTag property.
+    var proto1 = Object.getPrototypeOf(iter);
+    assertDeepEq(Reflect.ownKeys(proto1), ['next', Symbol.toStringTag]);
+
+    var desc = Object.getOwnPropertyDescriptor(proto1, 'next');
+    assertEq(desc.configurable, true);
+    assertEq(desc.enumerable, false);
+    assertEq(desc.writable, true);
+
+    // %IteratorPrototype%
+    var proto2 = Object.getPrototypeOf(proto1);
+    assertEq(Object.getPrototypeOf(proto2), Object.prototype);
+    assertEq(Object.prototype.toString.call(proto2), "[object Object]");
+
+    assertDeepEq(Reflect.ownKeys(proto2), [Symbol.iterator]);
+    assertEq(proto2[Symbol.iterator](), proto2);
+
+    // Check there's a single %IteratorPrototype% object.
+    if (iterProto === null)
+	iterProto = proto2;
+    else
+	assertEq(iterProto, proto2);
+}
+
+test(Array);
+test(String);
+test(Map);
+test(Set);