1 files changed, 61 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/arguments/mapped-unmapped-args.js b/js/src/jit-test/tests/arguments/mapped-unmapped-args.js
new file mode 100644
index 0000000000..d1b063be3d
--- /dev/null
+++ b/js/src/jit-test/tests/arguments/mapped-unmapped-args.js
@@ -0,0 +1,61 @@
+// An unmapped arguments object is created for strict functions or functions
+// with default/rest/destructuring args.
+
+load(libdir + "asserts.js");
+
+function testDefaults(a, b=3) {
+    a = 3;
+    b = 4;
+    assertEq(arguments.length, 1);
+    assertEq(arguments[0], 1);
+    assertEq(arguments[1], undefined);
+    arguments[0] = 5;
+    assertEq(a, 3);
+    assertThrowsInstanceOf(() => arguments.callee, TypeError);
+}
+testDefaults(1);
+
+function testRest(a, ...rest) {
+    a = 3;
+    assertEq(arguments.length, 3);
+    assertEq(arguments[0], 1);
+    assertEq(arguments[1], 2);
+    arguments[0] = 5;
+    assertEq(a, 3);
+    arguments[1] = 6;
+    assertEq(arguments[1], 6);
+    assertEq(rest.toString(), "2,3");
+    assertThrowsInstanceOf(() => arguments.callee, TypeError);
+}
+testRest(1, 2, 3);
+
+function testDestructuring(a, {foo, bar}, b) {
+    a = 3;
+    bar = 4;
+    b = 1;
+    assertEq(arguments.length, 3);
+    assertEq(arguments[0], 1);
+    assertEq(arguments[1].bar, 2);
+    assertEq(arguments[2], 9);
+    assertThrowsInstanceOf(() => arguments.callee, TypeError);
+}
+testDestructuring(1, {foo: 1, bar: 2}, 9);
+
+function testStrict(a) {
+    "use strict";
+    a = 3;
+    assertEq(arguments[0], 1);
+    arguments[0] = 8;
+    assertEq(a, 3);
+    assertThrowsInstanceOf(() => arguments.callee, TypeError);
+}
+testStrict(1, 2);
+
+function testMapped(a) {
+    a = 3;
+    assertEq(arguments[0], 3);
+    arguments[0] = 5;
+    assertEq(a, 5);
+    assertEq(arguments.callee, testMapped);
+}
+testMapped(1);