1 files changed, 36 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/cacheir/optimize-get-iterator-4.js b/js/src/jit-test/tests/cacheir/optimize-get-iterator-4.js
new file mode 100644
index 0000000000..a1ee65e784
--- /dev/null
+++ b/js/src/jit-test/tests/cacheir/optimize-get-iterator-4.js
@@ -0,0 +1,36 @@
+(() => {
+  let iterablesBase = [
+    [1,2],
+    [1,2,3],
+    [1,2,3],
+    [3,2,1],
+  ];
+
+  let iterables = [];
+  for (let i = 0; i < 1000; i++) {
+    iterables.push([...iterablesBase[i % iterablesBase.length]]);
+  }
+
+  iterables.push(new Map([[1, 3], [2,4]]).keys());
+
+  function testDestructuringInitialization(a) {
+    let [x,y] = a;
+    return y;
+  }
+
+  function testDestructuringAssignment(a) {
+    let x, y;
+    [x,y] = a;
+    return y;
+  }
+
+  for (let i = 0; i < iterables.length; i++) {
+    assertEq(testDestructuringInitialization(iterables[i]), 2);
+  }
+
+  // refresh the last iterator
+  iterables[iterables.length - 1] = new Map([[1, 3], [2,4]]).keys();
+  for (let i = 0; i < iterables.length; i++) {
+    assertEq(testDestructuringAssignment(iterables[i]), 2);
+  }
+})();