From 4bea7961671ec9b8f90467b21b6a72df5fd47a53 Mon Sep 17 00:00:00 2001
From: Matthew Berry <me@mattrb.com>
Date: Mon, 26 Feb 2024 20:33:49 +0000
Subject: [PATCH] [js_runtime/js_dev_runtime] Prefer Array.isArray over
 checking prototype

Closes https://github.com/dart-lang/sdk/pull/54990

GitOrigin-RevId: 9c51a86c10e70c5f92e8b72894f8d3de138cd17b
Change-Id: I4b74f3762ec720b0204331d0945da046be99ba33
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/353784
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Stephen Adams <sra@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>
---
 .../_internal/js_dev_runtime/patch/convert_patch.dart | 10 ++--------
 sdk/lib/_internal/js_runtime/lib/convert_patch.dart   | 11 ++---------
 2 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/sdk/lib/_internal/js_dev_runtime/patch/convert_patch.dart b/sdk/lib/_internal/js_dev_runtime/patch/convert_patch.dart
index ccff79da207..0a72a3a4665 100644
--- a/sdk/lib/_internal/js_dev_runtime/patch/convert_patch.dart
+++ b/sdk/lib/_internal/js_dev_runtime/patch/convert_patch.dart
@@ -54,10 +54,7 @@ _convertJsonToDart(json, reviver(Object? key, Object? value)) {
       return e;
     }
 
-    // This test is needed to avoid identifying '{"__proto__":[]}' as an Array.
-    // TODO(sra): Replace this test with cheaper '#.constructor === Array' when
-    // bug 621 below is fixed.
-    if (JS<bool>('!', 'Object.getPrototypeOf(#) === Array.prototype', e)) {
+    if (JS<bool>('!', 'Array.isArray(#)', e)) {
       // In-place update of the elements since JS Array is a Dart List.
       for (int i = 0; i < JS<int>('!', '#.length', e); i++) {
         // Use JS indexing to avoid range checks.  We know this is the only
@@ -99,10 +96,7 @@ _convertJsonToDartLazy(object) {
     return object;
   }
 
-  // This test is needed to avoid identifying '{"__proto__":[]}' as an array.
-  // TODO(sra): Replace this test with cheaper '#.constructor === Array' when
-  // bug https://code.google.com/p/v8/issues/detail?id=621 is fixed.
-  if (JS<bool>('!', 'Object.getPrototypeOf(#) !== Array.prototype', object)) {
+  if (JS<bool>('!', '!Array.isArray(#)', object)) {
     return _JsonMap(object);
   }
 
diff --git a/sdk/lib/_internal/js_runtime/lib/convert_patch.dart b/sdk/lib/_internal/js_runtime/lib/convert_patch.dart
index 856f29d225b..16ddaa2972a 100644
--- a/sdk/lib/_internal/js_runtime/lib/convert_patch.dart
+++ b/sdk/lib/_internal/js_runtime/lib/convert_patch.dart
@@ -54,10 +54,7 @@ _convertJsonToDart(json, reviver(Object? key, Object? value)) {
       return e;
     }
 
-    // This test is needed to avoid identifying '{"__proto__":[]}' as an Array.
-    // TODO(sra): Replace this test with cheaper '#.constructor === Array' when
-    // bug 621 below is fixed.
-    if (JS<bool>('bool', 'Object.getPrototypeOf(#) === Array.prototype', e)) {
+    if (JS<bool>('bool', 'Array.isArray(#)', e)) {
       // In-place update of the elements since JS Array is a Dart List.
       for (int i = 0; i < JS<int>('int', '#.length', e); i++) {
         // Use JS indexing to avoid range checks.  We know this is the only
@@ -99,11 +96,7 @@ _convertJsonToDartLazy(object) {
     return object;
   }
 
-  // This test is needed to avoid identifying '{"__proto__":[]}' as an array.
-  // TODO(sra): Replace this test with cheaper '#.constructor === Array' when
-  // bug https://code.google.com/p/v8/issues/detail?id=621 is fixed.
-  if (JS<bool>(
-      'bool', 'Object.getPrototypeOf(#) !== Array.prototype', object)) {
+  if (JS<bool>('bool', '!Array.isArray(#)', object)) {
     return _JsonMap(object);
   }