1 files changed, 53 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js b/js/src/tests/test262/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js
new file mode 100644
index 0000000000..3ea0dcc133
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Atomics/wait/undefined-index-defaults-to-zero.js
@@ -0,0 +1,53 @@
+// |reftest| skip-if(!this.hasOwnProperty('Atomics')||!this.hasOwnProperty('SharedArrayBuffer')||(this.hasOwnProperty('getBuildConfiguration')&&getBuildConfiguration()['arm64-simulator'])) -- Atomics,SharedArrayBuffer is not enabled unconditionally, ARM64 Simulator cannot emulate atomics
+// Copyright (C) 2018 Amal Hussein. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-atomics.wait
+description: >
+  An undefined index arg should translate to 0
+info: |
+  Atomics.wait( typedArray, index, value, timeout )
+
+  2.Let i be ? ValidateAtomicAccess(typedArray, index).
+    ...
+      2.Let accessIndex be ? ToIndex(requestIndex).
+
+      9.If IsSharedArrayBuffer(buffer) is false, throw a TypeError exception.
+        ...
+          3.If bufferData is a Data Block, return false
+
+          If value is undefined, then
+          Let index be 0.
+
+includes: [atomicsHelper.js]
+features: [Atomics, SharedArrayBuffer, TypedArray]
+---*/
+
+const RUNNING = 1;
+const TIMEOUT = $262.agent.timeouts.long;
+
+$262.agent.start(`
+  $262.agent.receiveBroadcast(function(sab) {
+    const i32a = new Int32Array(sab);
+    Atomics.add(i32a, ${RUNNING}, 1);
+
+    $262.agent.report(Atomics.wait(i32a, undefined, 0, ${TIMEOUT})); // undefined index => 0
+    $262.agent.leaving();
+  });
+`);
+
+const i32a = new Int32Array(
+  new SharedArrayBuffer(Int32Array.BYTES_PER_ELEMENT * 4)
+);
+
+$262.agent.safeBroadcast(i32a);
+$262.agent.waitUntil(i32a, RUNNING, 1);
+
+// Try to yield control to ensure the agent actually started to wait.
+$262.agent.tryYield();
+
+assert.sameValue(Atomics.notify(i32a, 0), 1, 'Atomics.notify(i32a, 0) returns 1'); // notify at index 0
+assert.sameValue(Atomics.notify(i32a, 0), 0, 'Atomics.notify(i32a, 0) returns 0'); // notify again at index 0, and 0 agents should be woken
+assert.sameValue($262.agent.getReport(), 'ok', '$262.agent.getReport() returns "ok"');
+
+reportCompare(0, 0);