1 files changed, 29 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/String/prototype/at/index-argument-tointeger.js b/js/src/tests/test262/built-ins/String/prototype/at/index-argument-tointeger.js
new file mode 100644
index 0000000000..1265d2412b
--- /dev/null
+++ b/js/src/tests/test262/built-ins/String/prototype/at/index-argument-tointeger.js
@@ -0,0 +1,29 @@
+// Copyright (C) 2020 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-string.prototype.at
+description: >
+  Property type and descriptor.
+info: |
+  String.prototype.at( index )
+
+  Let relativeIndex be ? ToInteger(index).
+
+features: [String.prototype.at]
+---*/
+assert.sameValue(typeof String.prototype.at, 'function');
+
+let valueOfCallCount = 0;
+let index = {
+  valueOf() {
+    valueOfCallCount++;
+    return 1;
+  }
+};
+
+let s = "01";
+
+assert.sameValue(s.at(index), '1', 's.at({valueOf() {valueOfCallCount++; return 1;}}) must return 1');
+assert.sameValue(valueOfCallCount, 1, 'The value of `valueOfCallCount` is 1');
+
+reportCompare(0, 0);