1 files changed, 20 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/arguments/mapped-define.js b/js/src/jit-test/tests/arguments/mapped-define.js
new file mode 100644
index 0000000000..820485608a
--- /dev/null
+++ b/js/src/jit-test/tests/arguments/mapped-define.js
@@ -0,0 +1,20 @@
+function f(a) {
+    assertEq(arguments[0], 1);
+
+    Object.defineProperty(arguments, 0, {value: 23, writable: true, configurable: true});
+    assertEq(arguments[0], 23);
+    assertEq(a, 23);
+
+    a = 12;
+    assertEq(a, 12);
+    assertEq(arguments[0], 12);
+
+    Object.defineProperty(arguments, 0, {value: 9, writable: false, configurable: false});
+    assertEq(arguments[0], 9);
+    assertEq(a, 9);
+
+    a = 4;
+    assertEq(arguments[0], 9);
+    assertEq(a, 4);
+}
+f(1);