[js_runtime/js_dev_runtime] Prefer Array.isArray over checking prototype

Closes #54990

GitOrigin-RevId: 9c51a86
Change-Id: I4b74f3762ec720b0204331d0945da046be99ba33
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/353784
Reviewed-by: Sigmund Cherem <[email protected]>
Reviewed-by: Stephen Adams <[email protected]>
Commit-Queue: Sigmund Cherem <[email protected]>

Author: mattrberry

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);
   }
 

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);
   }