[ddc] Attaching default type arg member signatures to JS native types.

Fixes 'member not found' issues arising from accessing default type arguments from JS literals.

Change-Id: I7cdfddcd70ee42a2941c8cb666570e161077281b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/307513
Reviewed-by: Nicholas Shahan <[email protected]>
Commit-Queue: Mark Zhou <[email protected]>

Author: Markzipan

sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/classes.dart

@@ -484,8 +484,10 @@ void _installPropertiesForGlobalObject(jsProto) {
 
 final _extensionMap = JS('', 'new Map()');
 
+/// Adds Dart properties to native JS types.
 void _applyExtension(jsType, dartExtType) {
-  // TODO(vsm): Not all registered js types are real.
+  // Exit early when encountering a JS type without a prototype (such as
+  // structs).
   if (jsType == null) return;
   var jsProto = JS<Object?>('', '#.prototype', jsType);
   if (jsProto == null) return;
@@ -509,7 +511,11 @@ void _applyExtension(jsType, dartExtType) {
   if (JS('!', '# !== #', dartExtType, JS_CLASS_REF(JSFunction))) {
     JS('', '#[#] = #', jsProto, _extensionType, dartExtType);
   }
+
+  // Attach member signature tags.
   JS('', '#[#] = #[#]', jsType, _methodSig, dartExtType, _methodSig);
+  JS('', '#[#] = #[#]', jsType, _methodsDefaultTypeArgSig, dartExtType,
+      _methodsDefaultTypeArgSig);
   JS('', '#[#] = #[#]', jsType, _fieldSig, dartExtType, _fieldSig);
   JS('', '#[#] = #[#]', jsType, _getterSig, dartExtType, _getterSig);
   JS('', '#[#] = #[#]', jsType, _setterSig, dartExtType, _setterSig);

tests/web/dynamic_generic_method_resolution_test.dart

@@ -0,0 +1,11 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Tests that generic function invocations have their default type arguments
+// resolved in a dynamic call when the type argument is a JS entity.
+
+void main() {
+  dynamic arrayLiteral = [];
+  arrayLiteral.map((v) => '$v');
+}