1 files changed, 34 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/TypedObject/prototypes.js b/js/src/jit-test/tests/TypedObject/prototypes.js
new file mode 100644
index 000000000..4a569e09e
--- /dev/null
+++ b/js/src/jit-test/tests/TypedObject/prototypes.js
@@ -0,0 +1,34 @@
+// API Surface Test: check that mutating prototypes
+// of type objects has no effect, and that mutating
+// the prototypes of typed objects is an error.
+
+if (!this.hasOwnProperty("TypedObject"))
+  quit();
+
+load(libdir + "asserts.js");
+
+var {StructType, uint32, Object, Any, storage, objectType} = TypedObject;
+
+function main() { // once a C programmer, always a C programmer.
+  var Uints = new StructType({f: uint32, g: uint32});
+  var p = Uints.prototype;
+  Uints.prototype = {}; // no effect
+  assertEq(p, Uints.prototype);
+
+  var uints = new Uints();
+  assertEq(uints.__proto__, p);
+  assertThrowsInstanceOf(() => uints.__proto__ = {},
+                         TypeError);
+  assertThrowsInstanceOf(() => Object.setPrototypeOf(uints, {}),
+                         TypeError);
+  assertEq(uints.__proto__, p);
+
+  var Uintss = Uints.array(2);
+  var p = Uintss.prototype;
+  Uintss.prototype = {}; // no effect
+  assertEq(p, Uintss.prototype);
+
+  print("Tests complete");
+}
+
+main();