1 files changed, 39 insertions, 0 deletions
diff --git a/js/src/tests/non262/Array/at.js b/js/src/tests/non262/Array/at.js
new file mode 100644
index 0000000000..e3227a3ec2
--- /dev/null
+++ b/js/src/tests/non262/Array/at.js
@@ -0,0 +1,39 @@
+function basic() {
+  assertEq([0].at(0), 0);
+  assertEq([0].at(-1), 0);
+
+  assertEq([].at(0), undefined);
+  assertEq([].at(-1), undefined);
+  assertEq([].at(1), undefined);
+
+  assertEq([0, 1].at(0), 0);
+  assertEq([0, 1].at(1), 1);
+  assertEq([0, 1].at(-2), 0);
+  assertEq([0, 1].at(-1), 1);
+
+  assertEq([0, 1].at(2), undefined);
+  assertEq([0, 1].at(-3), undefined);
+  assertEq([0, 1].at(-4), undefined);
+  assertEq([0, 1].at(Infinity), undefined);
+  assertEq([0, 1].at(-Infinity), undefined);
+  assertEq([0, 1].at(NaN), 0); // ToInteger(NaN) = 0
+}
+
+function obj() {
+  var o = {length: 0, [0]: "a", at: Array.prototype.at};
+
+  assertEq(o.at(0), undefined);
+  assertEq(o.at(-1), undefined);
+
+  o.length = 1;
+  assertEq(o.at(0), "a");
+  assertEq(o.at(-1), "a");
+  assertEq(o.at(1), undefined);
+  assertEq(o.at(-2), undefined);
+}
+
+basic();
+obj();
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);