Reland: [Android] Fix Text and ScrollView payloads that Props 2.0 sends wrong or drops

packages/react-native/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm

@@ -412,7 +412,8 @@ - (void)updateProps:(const Props::Shared &)props oldProps:(const Props::Shared &
 
   auto *scrollView = (RCTEnhancedScrollView *)_scrollView;
   if (oldScrollViewProps.snapToAlignment != newScrollViewProps.snapToAlignment) {
-    scrollView.snapToAlignment = RCTNSStringFromString(toString(newScrollViewProps.snapToAlignment));
+    scrollView.snapToAlignment =
+        RCTNSStringFromString(toString(newScrollViewProps.snapToAlignment.value_or(ScrollViewSnapToAlignment::Start)));
   }
 
   scrollView.snapToStart = newScrollViewProps.snapToStart;

packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm

@@ -67,7 +67,7 @@ static BOOL RCTViewIsInteractiveAccessibilityElement(UIView *view, const ViewPro
 
   // `role` wins over the legacy `accessibilityRole` when both are set, matching
   // how the traits themselves are resolved.
-  if (props.role != Role::None) {
+  if (props.role.value_or(Role::None) != Role::None) {
     static const std::unordered_set<Role> interactiveRoles{
         Role::Button,
         Role::Checkbox,
@@ -82,7 +82,7 @@ static BOOL RCTViewIsInteractiveAccessibilityElement(UIView *view, const ViewPro
         Role::Switch,
         Role::Tab,
         Role::Treeitem};
-    return interactiveRoles.contains(props.role);
+    return interactiveRoles.contains(*props.role);
   }
 
   static const std::unordered_set<std::string_view> interactiveAccessibilityRoles{
@@ -1690,8 +1690,9 @@ - (NSString *)accessibilityValue
   }
 
   NSMutableArray *valueComponents = [NSMutableArray new];
-  NSString *roleString = (props.role != Role::None) ? [NSString stringWithUTF8String:toString(props.role).c_str()]
-                                                    : [NSString stringWithUTF8String:props.accessibilityRole.c_str()];
+  NSString *roleString = (props.role.value_or(Role::None) != Role::None)
+      ? [NSString stringWithUTF8String:toString(*props.role).c_str()]
+      : [NSString stringWithUTF8String:props.accessibilityRole.c_str()];
 
   // In iOS, checkbox and radio buttons aren't recognized as traits. However,
   // because our apps use checkbox and radio buttons often, we should announce

packages/react-native/ReactCommon/react/renderer/components/scrollview/BaseScrollViewProps.cpp

@@ -80,7 +80,7 @@ BaseScrollViewProps::BaseScrollViewProps(
           rawProps,
           "decelerationRate",
           sourceProps.decelerationRate,
-          (Float)0.998)),
+          kDefaultDecelerationRate)),
       endDraggingSensitivityMultiplier(convertRawProp(
           context,
           rawProps,
@@ -427,10 +427,7 @@ SharedDebugStringConvertibleList BaseScrollViewProps::getDebugProps() const {
               "snapToInterval",
               snapToInterval,
               defaultScrollViewProps.snapToInterval),
-          debugStringConvertibleItem(
-              "snapToAlignment",
-              snapToAlignment,
-              defaultScrollViewProps.snapToAlignment),
+          debugStringConvertibleItem("snapToAlignment", snapToAlignment),
           debugStringConvertibleItem(
               "disableIntervalMomentum",
               disableIntervalMomentum,

packages/react-native/ReactCommon/react/renderer/components/scrollview/BaseScrollViewProps.h

@@ -41,7 +41,13 @@ class BaseScrollViewProps : public ViewProps {
   bool automaticallyAdjustContentInsets{};
   bool automaticallyAdjustsScrollIndicatorInsets{true};
   bool automaticallyAdjustKeyboardInsets{false};
-  Float decelerationRate{0.998f};
+#ifdef ANDROID
+  // ReactScrollView's initial rate.
+  static constexpr Float kDefaultDecelerationRate = 0.985f;
+#else
+  static constexpr Float kDefaultDecelerationRate = 0.998f;
+#endif
+  Float decelerationRate{kDefaultDecelerationRate};
   Float endDraggingSensitivityMultiplier{1};
   bool directionalLockEnabled{};
   ScrollViewIndicatorStyle indicatorStyle{};
@@ -63,7 +69,7 @@ class BaseScrollViewProps : public ViewProps {
   Point contentOffset{};
   EdgeInsets scrollIndicatorInsets{};
   Float snapToInterval{};
-  ScrollViewSnapToAlignment snapToAlignment{};
+  std::optional<ScrollViewSnapToAlignment> snapToAlignment{};
   bool disableIntervalMomentum{false};
   std::vector<Float> snapToOffsets{};
   bool snapToStart{true};

packages/react-native/ReactCommon/react/renderer/components/scrollview/platform/android/react/renderer/components/scrollview/HostPlatformScrollViewProps.cpp

@@ -49,7 +49,13 @@ HostPlatformScrollViewProps::HostPlatformScrollViewProps(
           rawProps,
           "endFillColor",
           sourceProps.endFillColor,
-          clearColor())) {}
+          clearColor())),
+      scrollsChildToFocus(convertRawProp(
+          context,
+          rawProps,
+          "scrollsChildToFocus",
+          sourceProps.scrollsChildToFocus,
+          true)) {}
 
 void HostPlatformScrollViewProps::setProp(
     const PropsParserContext& context,
@@ -69,6 +75,7 @@ void HostPlatformScrollViewProps::setProp(
     RAW_SET_PROP_SWITCH_CASE_BASIC(fadingEdgeLength);
     RAW_SET_PROP_SWITCH_CASE_BASIC(overScrollMode);
     RAW_SET_PROP_SWITCH_CASE_BASIC(endFillColor);
+    RAW_SET_PROP_SWITCH_CASE_BASIC(scrollsChildToFocus);
   }
 }
 
@@ -96,7 +103,11 @@ SharedDebugStringConvertibleList HostPlatformScrollViewProps::getDebugProps()
           debugStringConvertibleItem(
               "endFillColor",
               endFillColor,
-              defaultScrollViewProps.endFillColor)};
+              defaultScrollViewProps.endFillColor),
+          debugStringConvertibleItem(
+              "scrollsChildToFocus",
+              scrollsChildToFocus,
+              defaultScrollViewProps.scrollsChildToFocus)};
 }
 #endif
 
@@ -301,17 +312,9 @@ folly::dynamic HostPlatformScrollViewProps::getDiffProps(
   }
 
   if (snapToAlignment != oldProps->snapToAlignment) {
-    switch (snapToAlignment) {
-      case ScrollViewSnapToAlignment::Start:
-        result["snapToAlignment"] = "start";
-        break;
-      case ScrollViewSnapToAlignment::Center:
-        result["snapToAlignment"] = "center";
-        break;
-      case ScrollViewSnapToAlignment::End:
-        result["snapToAlignment"] = "end";
-        break;
-    }
+    result["snapToAlignment"] = snapToAlignment.has_value()
+        ? toString(*snapToAlignment)
+        : folly::dynamic(nullptr);
   }
 
   if (disableIntervalMomentum != oldProps->disableIntervalMomentum) {
@@ -380,6 +383,10 @@ folly::dynamic HostPlatformScrollViewProps::getDiffProps(
     result["endFillColor"] = *endFillColor;
   }
 
+  if (scrollsChildToFocus != oldProps->scrollsChildToFocus) {
+    result["scrollsChildToFocus"] = scrollsChildToFocus;
+  }
+
   return result;
 }
 

packages/react-native/ReactCommon/react/renderer/components/scrollview/platform/android/react/renderer/components/scrollview/HostPlatformScrollViewProps.h

@@ -38,6 +38,7 @@ class HostPlatformScrollViewProps : public BaseScrollViewProps {
   folly::dynamic fadingEdgeLength{};
   std::string overScrollMode{"auto"};
   SharedColor endFillColor{clearColor()};
+  bool scrollsChildToFocus{true};
 
 #pragma mark - DebugStringConvertible
 

packages/react-native/ReactCommon/react/renderer/components/scrollview/tests/ScrollViewPropsDiffTest.cpp

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+
+#include <react/renderer/components/scrollview/ScrollViewProps.h>
+#include <react/test_utils/PropsPayloads.h>
+
+#ifdef RN_SERIALIZABLE_STATE
+
+namespace facebook::react {
+
+namespace {
+
+using folly::dynamic;
+
+void expectPayloads(const std::vector<PropsCommit>& commits) {
+  expectPayloadsMatchRawProps<ScrollViewProps>(commits);
+}
+
+} // namespace
+
+// ReactScrollViewManager has a setter for it; with
+// enableExclusivePropsUpdateAndroid there is no rawProps fallback.
+TEST(ScrollViewPropsDiffTest, emitsScrollsChildToFocus) {
+  expectPayloads({{dynamic::object("scrollsChildToFocus", false)}});
+}
+
+// Android ScrollViews start with snapping alignment disabled, and
+// setSnapToAlignment disables it for null.
+TEST(
+    ScrollViewPropsDiffTest,
+    keepsAnExplicitSnapToAlignmentStartApartFromUnset) {
+  expectPayloads({
+      {dynamic::object("snapToAlignment", "start")},
+      {dynamic::object("snapToAlignment", "center")},
+      {dynamic::object("snapToAlignment", nullptr)},
+  });
+}
+
+// Android ScrollViews start decelerating at 0.985 (ReactScrollViewHelper).
+// A removed rate restores it; Props 1.5 sends null, which the setter reads as
+// 0.
+TEST(ScrollViewPropsDiffTest, emitsAnExplicitDecelerationRate) {
+  expectPayloads({
+      {dynamic::object("decelerationRate", 0.998)},
+      {dynamic::object("decelerationRate", nullptr),
+       dynamic::object("decelerationRate", 0.985)},
+  });
+}
+
+// The ScrollView managers turn both off for null.
+TEST(ScrollViewPropsDiffTest, removingNestedScrollAndMomentumEventsEmitsFalse) {
+  expectPayloads({
+      {dynamic::object("nestedScrollEnabled", true)(
+          "sendMomentumEvents", true)},
+      {dynamic::object("nestedScrollEnabled", nullptr)(
+           "sendMomentumEvents", nullptr),
+       dynamic::object("nestedScrollEnabled", false)(
+           "sendMomentumEvents", false)},
+  });
+}
+
+} // namespace facebook::react
+
+#endif

packages/react-native/ReactCommon/react/renderer/components/text/BaseTextProps.cpp

@@ -13,6 +13,8 @@
 #include <react/renderer/debug/DebugStringConvertibleItem.h>
 #include <react/utils/FloatComparison.h>
 
+#include <cmath>
+
 namespace facebook::react {
 
 static TextAttributes convertRawProp(
@@ -436,7 +438,9 @@ void BaseTextProps::appendTextAttributesProps(
   if (!floatEquality(
           textAttributes.letterSpacing,
           oldProps->textAttributes.letterSpacing)) {
-    result["letterSpacing"] = textAttributes.letterSpacing;
+    result["letterSpacing"] = std::isnan(textAttributes.letterSpacing)
+        ? folly::dynamic(nullptr)
+        : textAttributes.letterSpacing;
   }
 
   if (textAttributes.textTransform != oldProps->textAttributes.textTransform) {

packages/react-native/ReactCommon/react/renderer/components/text/tests/ParagraphPropsDiffTest.cpp

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+
+#include <react/renderer/components/text/ParagraphProps.h>
+#include <react/test_utils/PropsPayloads.h>
+
+#ifdef RN_SERIALIZABLE_STATE
+
+namespace facebook::react {
+
+using folly::dynamic;
+
+// ReactTextViewManager resets letterSpacing to 0 for null;
+// ReactTextView.setLetterSpacing ignores NaN.
+TEST(ParagraphPropsDiffTest, removingLetterSpacingEmitsNull) {
+  expectPayloadsMatchRawProps<ParagraphProps>({
+      {dynamic::object("letterSpacing", 4.0)},
+      {dynamic::object("letterSpacing", nullptr)},
+  });
+}
+
+} // namespace facebook::react
+
+#endif

packages/react-native/ReactCommon/react/renderer/components/view/AccessibilityProps.cpp

@@ -18,12 +18,12 @@ namespace facebook::react {
 // members. This makes accessibilityTraits the single source of truth.
 // See: github.com/facebook/react-native/issues/57515
 static AccessibilityTraits deriveAccessibilityTraits(
-    Role role,
+    std::optional<Role> role,
     const std::string& accessibilityRole,
     const std::optional<AccessibilityState>& accessibilityState) {
   AccessibilityTraits traits = AccessibilityTraits::None;
-  if (role != Role::None) {
-    fromString(toString(role), traits);
+  if (role.value_or(Role::None) != Role::None) {
+    fromString(toString(*role), traits);
   } else if (!accessibilityRole.empty()) {
     fromString(accessibilityRole, traits);
   }
@@ -179,16 +179,15 @@ AccessibilityProps::AccessibilityProps(
   auto* accessibilityRoleValue = rawProps.at("accessibilityRole");
   auto* roleValue = rawProps.at("role");
 
-  if (accessibilityRoleValue == nullptr ||
-      !accessibilityRoleValue->hasValue()) {
+  if (accessibilityRoleValue == nullptr) {
     accessibilityRole = sourceProps.accessibilityRole;
-  } else {
+  } else if (accessibilityRoleValue->hasValue()) {
     fromRawValue(context, *accessibilityRoleValue, accessibilityRole);
   }
 
-  if (roleValue == nullptr || !roleValue->hasValue()) {
+  if (roleValue == nullptr) {
     role = sourceProps.role;
-  } else {
+  } else if (roleValue->hasValue()) {
     fromRawValue(context, *roleValue, role);
   }
 

packages/react-native/ReactCommon/react/renderer/components/view/AccessibilityProps.h

@@ -56,7 +56,7 @@ class AccessibilityProps {
   bool onAccessibilityEscape{};
   bool onAccessibilityAction{};
   ImportantForAccessibility importantForAccessibility{ImportantForAccessibility::Auto};
-  Role role{Role::None};
+  std::optional<Role> role{};
   std::string testId;
 
 #pragma mark - DebugStringConvertible