1 files changed, 31 insertions, 0 deletions
diff --git a/js/src/tests/ecma_6/Symbol/property-nonwritable.js b/js/src/tests/ecma_6/Symbol/property-nonwritable.js
new file mode 100644
index 000000000..3e58383c7
--- /dev/null
+++ b/js/src/tests/ecma_6/Symbol/property-nonwritable.js
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/ */
+
+var sym = Symbol.for("moon");
+function checkNotWritable(obj) {
+    // In sloppy mode, assigning to a nonwritable property silently fails.
+    obj[sym] = "portals";
+    assertEq(obj[sym], "cheese");
+
+    // In strict mode code, it throws.
+    assertThrowsInstanceOf(function () { "use strict"; obj[sym] = "robots"; }, TypeError);
+    assertEq(obj[sym], "cheese");
+}
+
+var x = {};
+Object.defineProperty(x, sym, {
+    configurable: true,
+    enumerable: true,
+    value: "cheese",
+    writable: false
+});
+
+checkNotWritable(x);
+
+// Assignment can't shadow inherited nonwritable properties either.
+var y = Object.create(x);
+checkNotWritable(y);
+checkNotWritable(Object.create(y));
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);