fix: cache protocol UIAppearance accessors

DjDeveloperr · DjDeveloperr · commit 9699fefc2e16 · 2026-06-29T09:39:58.000-04:00
diff --git a/HANDOFF.md b/HANDOFF.md
@@ -111,6 +111,35 @@ During this thread `agent-device` was version `0.18.0`; the npm package is
 
 ## Current Verified State
 
+Update from 2026-06-29 09:38 EDT:
+
+- Simulator-only rule remains active. Do not use physical iPhone/iPad devices.
+- GitHub Actions run `28373879852` on `cb4fc1a9` kept setup, dependency
+  install, FFI boundary, V8 download, libffi build, metadata generation,
+  NativeScript build, CLI build, and macOS tests green, but still failed iOS
+  only in `ApiTests.js Appearance`: `UILabel.appearance().textColor` read back
+  `undefined`.
+- Narrow follow-up runtime fix in progress:
+  - UIAppearance property reads/writes can resolve through protocol-defined
+    accessors, bypassing `NativeApiObjectHostObject::get/set`.
+  - Protocol property setters now populate the same target-class-scoped
+    UIAppearance expando cache after a successful native setter call.
+  - Protocol property getters now consult that cache before falling through to
+    the native getter, matching the object-host read path.
+  - Static `appearance*` result tagging now prefers UIKit's exact
+    `<Customizable class: ...>` description when tagging a known appearance
+    selector result, then falls back to the dispatch class.
+- Local verification after this patch:
+  - Runtime RN JS tests passed:
+    `for f in packages/react-native/test/*.test.js; do node "$f" || exit 1; done`.
+  - `npm run check:ffi-boundaries` passed.
+  - `git diff --check` passed.
+  - `npm run build:macos-cli` passed.
+- Not done:
+  - Commit/push this protocol-accessor UIAppearance cache fix and watch fresh
+    PR CI.
+  - If CI turns green, resume the dedicated simulator-only RNS parity sweep.
+
 Update from 2026-06-29 09:00 EDT:
 
 - Simulator-only rule remains active. Do not use physical iPhone/iPad devices.
diff --git a/NativeScript/ffi/shared/bridge/HostObjects.mm b/NativeScript/ffi/shared/bridge/HostObjects.mm
@@ -566,18 +566,12 @@ bool objectGetPathCanReadRuntimeProperty(id object,
 constexpr const char* kNativeApiAppearanceClassNameExpando =
     "__nativeApiAppearanceClassName";
 
-Class appearanceProxyCustomizableClassFromDescription(id object) {
+Class appearanceProxyCustomizableClassFromExactDescription(id object) {
 #if TARGET_OS_IPHONE
   if (object == nil) {
     return Nil;
   }
 
-  const char* runtimeClassName = object_getClassName(object);
-  if (runtimeClassName == nullptr ||
-      std::strstr(runtimeClassName, "Appearance") == nullptr) {
-    return Nil;
-  }
-
   NSString* description = [object description];
   NSString* prefix = @"<Customizable class: ";
   if (description.length <= prefix.length + 1 ||
@@ -594,6 +588,24 @@ Class appearanceProxyCustomizableClassFromDescription(id object) {
 #endif
 }
 
+Class appearanceProxyCustomizableClassFromDescription(id object) {
+#if TARGET_OS_IPHONE
+  if (object == nil) {
+    return Nil;
+  }
+
+  const char* runtimeClassName = object_getClassName(object);
+  if (runtimeClassName == nullptr ||
+      std::strstr(runtimeClassName, "Appearance") == nullptr) {
+    return Nil;
+  }
+
+  return appearanceProxyCustomizableClassFromExactDescription(object);
+#else
+  return Nil;
+#endif
+}
+
 Class taggedAppearanceProxyClass(
     Runtime& runtime, const std::shared_ptr<NativeApiBridge>& bridge,
     id object) {
@@ -617,6 +629,28 @@ Class taggedAppearanceProxyClass(
   return "__nativeApiAppearance:" + property;
 }
 
+Value cachedAppearanceProxyPropertyValue(
+    Runtime& runtime, const std::shared_ptr<NativeApiBridge>& bridge,
+    id object, const std::string& property) {
+  if (Class appearanceClass =
+          taggedAppearanceProxyClass(runtime, bridge, object)) {
+    return bridge->findObjectExpando(
+        runtime, appearanceClass, appearanceProxyExpandoPropertyKey(property));
+  }
+  return Value::undefined();
+}
+
+void cacheAppearanceProxyPropertyValue(
+    Runtime& runtime, const std::shared_ptr<NativeApiBridge>& bridge,
+    id object, const std::string& property, const Value& value) {
+  if (Class appearanceClass =
+          taggedAppearanceProxyClass(runtime, bridge, object)) {
+    bridge->setObjectExpando(runtime, appearanceClass,
+                             appearanceProxyExpandoPropertyKey(property),
+                             value);
+  }
+}
+
 class NativeApiSuperHostObject final : public HostObject {
  public:
   NativeApiSuperHostObject(std::shared_ptr<NativeApiBridge> bridge,
@@ -1300,13 +1334,10 @@ Value get(Runtime& runtime, const PropNameID& name) override {
     if (!expando.isUndefined()) {
       return expando;
     }
-    if (Class appearanceClass =
-            taggedAppearanceProxyClass(runtime, bridge_, object_)) {
-      Value appearanceExpando = bridge_->findObjectExpando(
-          runtime, appearanceClass, appearanceProxyExpandoPropertyKey(property));
-      if (!appearanceExpando.isUndefined()) {
-        return appearanceExpando;
-      }
+    Value appearanceExpando =
+        cachedAppearanceProxyPropertyValue(runtime, bridge_, object_, property);
+    if (!appearanceExpando.isUndefined()) {
+      return appearanceExpando;
     }
 
     // Fast path: cached metadata property-getter resolution. Skips the
@@ -1778,12 +1809,8 @@ throw JSError(
         Value args[] = {Value(runtime, value)};
         callObjCSelector(runtime, bridge_, object_, false,
                          setterMember.selectorName, &setterMember, args, 1);
-        if (Class appearanceClass =
-                taggedAppearanceProxyClass(runtime, bridge_, object_)) {
-          bridge_->setObjectExpando(
-              runtime, appearanceClass,
-              appearanceProxyExpandoPropertyKey(property), value);
-        }
+        cacheAppearanceProxyPropertyValue(runtime, bridge_, object_, property,
+                                          value);
         NATIVE_API_SET_RETURN(true);
       }
     }
@@ -1793,12 +1820,8 @@ throw JSError(
       Value args[] = {Value(runtime, value)};
       callObjCSelector(runtime, bridge_, object_, false,
                        *setterSelectorName, nullptr, args, 1);
-      if (Class appearanceClass =
-              taggedAppearanceProxyClass(runtime, bridge_, object_)) {
-        bridge_->setObjectExpando(
-            runtime, appearanceClass,
-            appearanceProxyExpandoPropertyKey(property), value);
-      }
+      cacheAppearanceProxyPropertyValue(runtime, bridge_, object_, property,
+                                        value);
       if (!objectGetPathCanReadRuntimeProperty(object_, property)) {
         bridge_->setObjectExpando(runtime, object_, property, value);
       }
@@ -1864,7 +1887,12 @@ void tagStaticAppearanceNativeResult(
   if (bridge == nullptr || appearanceClass == Nil || native == nil) {
     return;
   }
-  const char* className = class_getName(appearanceClass);
+  Class customizableClass =
+      appearanceProxyCustomizableClassFromExactDescription(native);
+  if (customizableClass == Nil) {
+    customizableClass = appearanceClass;
+  }
+  const char* className = class_getName(customizableClass);
   if (className == nullptr || className[0] == '\0') {
     return;
   }
@@ -2139,9 +2167,7 @@ throw JSError(runtime,
                                 .getHostObject<NativeApiObjectHostObject>(
                                     runtime)
                                 ->object();
-                bridge->setObjectExpando(
-                    runtime, native, kNativeApiAppearanceClassNameExpando,
-                    makeString(runtime, symbol.runtimeName));
+                tagStaticAppearanceNativeResult(runtime, bridge, cls, native);
               }
             }
             return result;
@@ -2647,6 +2673,11 @@ Value makeProtocolPropertyGetter(Runtime& runtime, NativeApiMember member,
             throw JSError(
                 runtime, "Protocol property requires a native receiver.");
           }
+          Value appearanceExpando = cachedAppearanceProxyPropertyValue(
+              runtime, bridge, receiver, member.name);
+          if (!appearanceExpando.isUndefined()) {
+            return appearanceExpando;
+          }
           NativeApiMember getterMember = member;
           if (auto selector = respondingPropertyGetterSelector(
                   receiver, member.name, member.selectorName)) {
@@ -2692,9 +2723,12 @@ throw JSError(
           NativeApiMember setterMember = member;
           setterMember.selectorName = member.setterSelectorName;
           setterMember.signatureOffset = member.setterSignatureOffset;
-          return callObjCSelector(runtime, bridge, receiver, receiverIsClass,
-                                  setterMember.selectorName, &setterMember,
-                                  args, 1);
+          Value result = callObjCSelector(
+              runtime, bridge, receiver, receiverIsClass,
+              setterMember.selectorName, &setterMember, args, 1);
+          cacheAppearanceProxyPropertyValue(runtime, bridge, receiver,
+                                            member.name, args[0]);
+          return result;
         });
   }
 
diff --git a/PROGRESS.md b/PROGRESS.md
@@ -17,6 +17,38 @@ TypeScript/UI worklets.
 
 ## Latest Update - 2026-06-29
 
+### 2026-06-29 09:38 EDT - cached protocol-backed UIAppearance accessors
+
+- Goal:
+  - Keep PR #46 on the generic runtime primitive path and unblock the final
+    simulator-only RN Screens parity sweep; no physical devices were used.
+- CI finding:
+  - GitHub Actions run `28373879852` on `cb4fc1a9` kept builds and macOS tests
+    green, but still failed iOS `ApiTests.js Appearance` only:
+    `UILabel.appearance().textColor` read back as `undefined`.
+  - The metadata-backed setter cache was still not enough. The remaining path
+    is consistent with UIAppearance properties resolving through
+    protocol-defined accessors, bypassing the object-host get/set cache.
+- Changes:
+  - Added shared UIAppearance cache helpers for target-class-scoped property
+    values.
+  - Protocol property setters now cache UIAppearance values after successful
+    native setter calls.
+  - Protocol property getters now read the UIAppearance cache before falling
+    through to native getters.
+  - Static `appearance*` result tagging now prefers UIKit's exact
+    `<Customizable class: ...>` proxy description for known appearance selector
+    returns, then falls back to the dispatch class.
+- Verification:
+  - Runtime RN JS tests passed:
+    `for f in packages/react-native/test/*.test.js; do node "$f" || exit 1; done`.
+  - `npm run check:ffi-boundaries` passed.
+  - `git diff --check` passed.
+  - `npm run build:macos-cli` passed.
+- Still next:
+  - Commit/push the protocol-accessor cache fix, watch fresh PR CI, then
+    return to the dedicated simulator-only RNS parity sweep if CI is green.
+
 ### 2026-06-29 09:00 EDT - cached metadata-backed UIAppearance setters
 
 - Goal:
