1 files changed, 58 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Iterator/prototype/map/mapper-args.js b/js/src/tests/test262/built-ins/Iterator/prototype/map/mapper-args.js
new file mode 100644
index 0000000000..132fcdeeee
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Iterator/prototype/map/mapper-args.js
@@ -0,0 +1,58 @@
+// |reftest| shell-option(--enable-iterator-helpers) skip-if(!this.hasOwnProperty('Iterator')||!xulRuntime.shell) -- iterator-helpers is not enabled unconditionally, requires shell-options
+// Copyright (C) 2023 Michael Ficarra. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-iteratorprototype.map
+description: >
+  Iterator.prototype.map mapper is passed the yielded value and a counter as arguments
+info: |
+  %Iterator.prototype%.map ( mapper )
+
+  5.b.iv. Let mapped be Completion(Call(mapper, undefined, « value, 𝔽(counter) »)).
+
+features: [iterator-helpers]
+flags: []
+---*/
+function* g() {
+  yield 'a';
+  yield 'b';
+  yield 'c';
+  yield 'd';
+  yield 'e';
+}
+
+let assertionCount = 0;
+let iter = g().map((v, count) => {
+  switch (v) {
+    case 'a':
+      assert.sameValue(count, 0);
+      ++assertionCount;
+      return 0;
+    case 'b':
+      assert.sameValue(count, 1);
+      ++assertionCount;
+      return 1;
+    case 'c':
+      assert.sameValue(count, 2);
+      ++assertionCount;
+      return 2;
+    case 'd':
+      assert.sameValue(count, 3);
+      ++assertionCount;
+      return 3;
+    case 'e':
+      assert.sameValue(count, 4);
+      ++assertionCount;
+      return 4;
+    default:
+      throw new Error();
+  }
+});
+
+assert.sameValue(assertionCount, 0);
+
+for (let i of iter);
+
+assert.sameValue(assertionCount, 5);
+
+reportCompare(0, 0);