fix: construct JS subclasses through remembered init

Author: DjDeveloperr

NativeScript/ffi/shared/bridge/Install.mm

@@ -626,6 +626,15 @@ function unavailableInitializerError(error) {
       /Objective-C selector is not available/.test(String(error.message || error));
   }
 
+  function shouldUseAllocInitConstructor(constructable, wrapper) {
+    var target = wrapper || constructable;
+    try {
+      return !!(target && target.__nativeApiUseAllocInitConstructor);
+    } catch (_) {
+      return false;
+    }
+  }
+
   function constructNativeInstance(nativeClass, args, rememberInstance) {
     if (args.length === 1 &&
         args[0] &&
@@ -784,7 +793,8 @@ function wrapNativeClass(nativeClass) {
           );
         }
       }
-      if (args.length > 0) {
+      if (args.length > 0 ||
+          shouldUseAllocInitConstructor(constructable, wrapper)) {
         return rememberInstanceClass(constructNativeInstance(nativeClass, args, rememberInstanceClass));
       }
       if (typeof nativeClass.new !== 'function') {
@@ -817,6 +827,15 @@ function rememberInstanceClass(instance) {
             nativeExtensionOptionsWithIterator(options, extensionMethods);
           var extendedNativeClass = api.__extendClass(nativeClass, extensionMethods, extendOptions);
           var extended = wrapNativeClass(extendedNativeClass);
+          try {
+            Object.defineProperty(extended, '__nativeApiUseAllocInitConstructor', {
+              configurable: false,
+              enumerable: false,
+              writable: false,
+              value: true
+            });
+          } catch (_) {
+          }
           try {
             Object.setPrototypeOf(extended, wrapper || constructable);
           } catch (_) {
@@ -1456,17 +1475,26 @@ function materializeTypeScriptNativeClass(constructor) {
 	        options.exposedMethods = constructor.ObjCExposedMethods;
 	      }
 
-		      var nativeBase = nativeClassLikeHandle(baseWrapper);
-		      var extensionMethods =
-		        nativeExtensionMethodsWithIndexedCollectionAliases(constructor.prototype || {});
-		      options = nativeExtensionOptionsWithIterator(options, extensionMethods);
-		      var nativeClass = api.__extendClass(nativeBase, extensionMethods, options);
-	      var wrapper = wrapNativeClass(nativeClass);
-	      state.wrapper = wrapper;
+      var nativeBase = nativeClassLikeHandle(baseWrapper);
+      var extensionMethods =
+        nativeExtensionMethodsWithIndexedCollectionAliases(constructor.prototype || {});
+      options = nativeExtensionOptionsWithIterator(options, extensionMethods);
+      var nativeClass = api.__extendClass(nativeBase, extensionMethods, options);
+      var wrapper = wrapNativeClass(nativeClass);
+      state.wrapper = wrapper;
+      try {
+        Object.defineProperty(wrapper, '__nativeApiUseAllocInitConstructor', {
+          configurable: false,
+          enumerable: false,
+          writable: false,
+          value: true
+        });
+      } catch (_) {
+      }
 
-	      try {
-	        Object.setPrototypeOf(constructor, wrapper);
-	      } catch (_) {
+      try {
+        Object.setPrototypeOf(constructor, wrapper);
+      } catch (_) {
 	      }
 	      try {
 	        api.__rememberClassWrapper(nativeClass, constructor, extensionMethods);

PROGRESS.md

@@ -15,7 +15,53 @@ TypeScript/UI worklets.
   Objective-C/UIKit.
 - Track the runtime API surface in `RN_API.md`.
 
-## Latest Update - 2026-06-29
+## Latest Update - 2026-06-30
+
+### 2026-06-30 00:10 EDT - JS subclasses use remembered alloc/init construction
+
+- Scope check:
+  - This remains PR #46 RN-module branch stabilization after the split from
+    `refactor`. The change is a generic NativeScript JS-subclass construction
+    primitive, not a React Native Screens shim and not direct engine backend
+    refactor work.
+  - Simulator-only rule remains active; no physical devices were used.
+- CI finding:
+  - GitHub Actions run `28418328502` on `bd5c2640` kept setup, dependency
+    install, FFI boundary check, V8 download, libffi build, metadata
+    generation, NativeScript build, CLI build, and macOS tests green.
+  - iOS simulator still timed out in `ApiTests.js NSMutableArrayMethods`.
+  - The canceled diagnostic run `28417161267` showed macOS entering JS `init`
+    and the native callback normally, but iOS repeatedly called the JS `count`
+    getter with missing `_array` before JS `init` or the native callback logged
+    anything. That points to Objective-C/Foundation probing the JS-backed
+    `NSMutableArray` subclass during zero-argument `+new`, before the JS
+    receiver has been associated and initialized.
+- Change:
+  - JS-extended native classes now opt into alloc/init construction even for
+    zero-argument constructors. `.extend(...)` wrappers and TypeScript
+    `NativeClass` materialization wrappers are tagged with
+    `__nativeApiUseAllocInitConstructor`.
+  - The generic native-class constructor now routes flagged zero-argument
+    subclasses through `alloc`, remembers the receiver, and then invokes the
+    selected initializer instead of raw `nativeClass.new()`.
+  - Source coverage now guards the alloc/init flag and constructor path so this
+    does not regress back to raw `+new` for JS-backed subclasses.
+- Verification:
+  - `node packages/react-native/test/runtime-instance-selector-base-dispatch.test.js`
+    passed.
+  - `node packages/react-native/test/runtime-indexed-collection-alias.test.js`
+    passed.
+  - Runtime RN JS tests passed:
+    `for f in packages/react-native/test/*.test.js; do node "$f" || exit 1; done`.
+  - `git diff --check` passed.
+  - `npm run check:ffi-boundaries` passed.
+  - `npm run build:macos-cli` passed.
+- Still next:
+  - Commit/push this alloc/init construction fix and watch fresh PR CI for the
+    iOS simulator `ApiTests.js NSMutableArrayMethods` result.
+  - If iOS still hangs, compare the verbose spec/log output: if JS `init` now
+    appears before the first missing `_array` count call, the next fix should be
+    a generic construction-state callback policy rather than an RNS workaround.
 
 ### 2026-06-29 23:30 EDT - initializer result wrapper cache preservation
 

packages/react-native/test/runtime-instance-selector-base-dispatch.test.js

@@ -26,6 +26,16 @@ for (const relativePath of [
       source.includes(": selectorFunction"),
     `${relativePath}: class selector wrappers should keep base invocation support while instance selectors use engine dispatch`,
   );
+  const allocInitFlagDefinitions =
+    source.match(/Object\.defineProperty\([^,]+, '__nativeApiUseAllocInitConstructor'/g) || [];
+  assert(
+    source.includes("function shouldUseAllocInitConstructor(constructable, wrapper)") &&
+      source.includes("target.__nativeApiUseAllocInitConstructor") &&
+      source.includes("args.length > 0 ||") &&
+      source.includes("shouldUseAllocInitConstructor(constructable, wrapper)") &&
+      allocInitFlagDefinitions.length >= 2,
+    `${relativePath}: JS-extended native classes should use alloc/init construction so receivers are remembered before init dispatch`,
+  );
 }
 
 for (const relativePath of [