From 0feec6795ca0d20189b9a1ef17e1a29ca55972fc Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 20 Feb 2026 21:22:12 +0000
Subject: [PATCH 1/2] Initial plan


From 35eb2836338b0c222ff703237a9b03192acadc66 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 20 Feb 2026 21:25:17 +0000
Subject: [PATCH 2/2] Fix isSupported() for Iterator helpers to accept native
 function-based Iterator

The typeof check `typeof IteratorConstructor === 'object'` incorrectly
returns false for native Iterator in Chromium where Iterator is a function.
Changed to also accept 'function' type.

Co-authored-by: mattcosta7 <8616962+mattcosta7@users.noreply.github.com>
---
 src/iterator-helpers.ts  |  2 +-
 test/iterator-helpers.js | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/src/iterator-helpers.ts b/src/iterator-helpers.ts
index ef54c58..af98ee5 100644
--- a/src/iterator-helpers.ts
+++ b/src/iterator-helpers.ts
@@ -316,7 +316,7 @@ export function isSupported(): boolean {
     'every' in IteratorPrototype &&
     'find' in IteratorPrototype &&
     IteratorConstructor !== undefined &&
-    typeof IteratorConstructor === 'object' &&
+    (typeof IteratorConstructor === 'object' || typeof IteratorConstructor === 'function') &&
     IteratorConstructor !== null &&
     'from' in IteratorConstructor
   )
diff --git a/test/iterator-helpers.js b/test/iterator-helpers.js
index 78c7687..1c717e8 100644
--- a/test/iterator-helpers.js
+++ b/test/iterator-helpers.js
@@ -11,6 +11,40 @@ describe('Iterator helpers', () => {
     expect(isPolyfilled()).to.equal(false)
   })
 
+  it('isSupported returns true when Iterator is a function (native support)', () => {
+    // Native Iterator in Chromium is a function, not an object.
+    // Simulate this by temporarily replacing globalThis.Iterator with a function.
+    const original = globalThis.Iterator
+    try {
+      apply() // ensure polyfill is applied first so prototype methods exist
+      const proto = Object.getPrototypeOf(Object.getPrototypeOf([][Symbol.iterator]()))
+      // Create a function-based Iterator with a `from` method, like native Chromium
+      globalThis.Iterator = function Iterator() {}
+      globalThis.Iterator.from = function from() {}
+      // Assign all required methods to the iterator prototype
+      for (const method of [
+        'map',
+        'filter',
+        'take',
+        'drop',
+        'flatMap',
+        'reduce',
+        'toArray',
+        'forEach',
+        'some',
+        'every',
+        'find',
+      ]) {
+        if (!(method in proto)) {
+          proto[method] = function () {}
+        }
+      }
+      expect(isSupported()).to.equal(true)
+    } finally {
+      globalThis.Iterator = original
+    }
+  })
+
   // Helper to create an iterator from an array
   function* arrayIterator(arr) {
     for (const item of arr) {