Fabric: Simplified way to specialize ComponentName in ConcreteShadowNode class template

Summary:
@public
Previously, all ConcreteShadowNode subclasses had to override `getComponentName()` function to specialize a name of the component. And often it was all that those subclasses do. Now, it's a template argument; and many ShadowNode classes can be created as oneliners via *just* specializing  ConcreteShadowNode template.

Unfortunately, C++ does not allow to use `std::string`s or string literals as template arguments, but it allows to use pointers. Moreover, those pointers must point to some linked data, hence, those values must be declared in .cpp (not .h) files. For simplicity, we put those constants in Props classes, (but this is not a strong requirement).

Reviewed By: mdvacca

Differential Revision: D8942826

fbshipit-source-id: 4fd517e2485eb8f8c20a51df9b3496941856d8a5

ReactCommon/fabric/components/activityindicator/ActivityIndicatorViewShadowNode.cpp

@@ -5,14 +5,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include <fabric/components/activityindicator/ActivityIndicatorViewShadowNode.h>
+#include "ActivityIndicatorViewShadowNode.h"
 
 namespace facebook {
 namespace react {
 
-ComponentName ActivityIndicatorViewShadowNode::getComponentName() const {
+const char ActivityIndicatorViewComponentName[] = "ActivityIndicatorView";
-  return ComponentName("ActivityIndicatorView");
-}
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/activityindicator/ActivityIndicatorViewShadowNode.h

@@ -13,18 +13,16 @@
 namespace facebook {
 namespace react {
 
+extern const char ActivityIndicatorViewComponentName[];
+
 /*
  * `ShadowNode` for <ActivityIndicatorView> component.
  */
-class ActivityIndicatorViewShadowNode final:
+using ActivityIndicatorViewShadowNode =
-  public ConcreteViewShadowNode<ActivityIndicatorViewProps> {
+  ConcreteViewShadowNode<
-
+    ActivityIndicatorViewComponentName,
-public:
+    ActivityIndicatorViewProps
-
+  >;
-  using ConcreteViewShadowNode::ConcreteViewShadowNode;
-
-  ComponentName getComponentName() const override;
-};
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/image/ImageShadowNode.cpp

@@ -14,9 +14,7 @@
 namespace facebook {
 namespace react {
 
-ComponentName ImageShadowNode::getComponentName() const {
+const char ImageComponentName[] = "Image";
-  return ComponentName("Image");
-}
 
 void ImageShadowNode::setImageManager(const SharedImageManager &imageManager) {
   ensureUnsealed();

ReactCommon/fabric/components/image/ImageShadowNode.h

@@ -16,18 +16,22 @@
 namespace facebook {
 namespace react {
 
+extern const char ImageComponentName[];
+
 /*
  * `ShadowNode` for <Image> component.
  */
 class ImageShadowNode final:
-  public ConcreteViewShadowNode<ImageProps, ImageEventEmitter> {
+  public ConcreteViewShadowNode<
+    ImageComponentName,
+    ImageProps,
+    ImageEventEmitter
+  > {
 
 public:
 
   using ConcreteViewShadowNode::ConcreteViewShadowNode;
 
-  ComponentName getComponentName() const override;
-
   /*
    * Associates a shared `ImageManager` with the node.
    */

ReactCommon/fabric/components/root/RootProps.h

@@ -24,7 +24,6 @@ class RootProps final:
   public ViewProps {
 
 public:
-
   RootProps() = default;
   RootProps(
     const RootProps &sourceProps,

ReactCommon/fabric/components/root/RootShadowNode.cpp

@@ -12,9 +12,7 @@
 namespace facebook {
 namespace react {
 
-ComponentName RootShadowNode::getComponentName() const {
+const char RootComponentName[] = "RootView";
-  return ComponentName("RootView");
-}
 
 void RootShadowNode::layout() {
   ensureUnsealed();

ReactCommon/fabric/components/root/RootShadowNode.h

@@ -21,6 +21,8 @@ class RootShadowNode;
 using SharedRootShadowNode = std::shared_ptr<const RootShadowNode>;
 using UnsharedRootShadowNode = std::shared_ptr<RootShadowNode>;
 
+extern const char RootComponentName[];
+
 /*
  * `ShadowNode` for the root component.
  * Besides all functionality of the `View` component, `RootShadowNode` contains
@@ -28,14 +30,15 @@ using UnsharedRootShadowNode = std::shared_ptr<RootShadowNode>;
  * shadow tree.
  */
 class RootShadowNode final:
-  public ConcreteViewShadowNode<RootProps> {
+  public ConcreteViewShadowNode<
+    RootComponentName,
+    RootProps
+  > {
 
 public:
 
   using ConcreteViewShadowNode::ConcreteViewShadowNode;
 
-  ComponentName getComponentName() const override;
-
   /*
    * Layouts the shadow tree.
    */

ReactCommon/fabric/components/scrollview/ScrollViewShadowNode.cpp

@@ -14,9 +14,7 @@
 namespace facebook {
 namespace react {
 
-ComponentName ScrollViewShadowNode::getComponentName() const {
+const char ScrollViewComponentName[] = "ScrollView";
-  return ComponentName("ScrollView");
-}
 
 void ScrollViewShadowNode::updateLocalData() {
   ensureUnsealed();

ReactCommon/fabric/components/scrollview/ScrollViewShadowNode.h

@@ -7,8 +7,6 @@
 
 #pragma once
 
-#include <memory>
-
 #include <fabric/components/scrollview/ScrollViewEventEmitter.h>
 #include <fabric/components/scrollview/ScrollViewProps.h>
 #include <fabric/components/view/ConcreteViewShadowNode.h>
@@ -17,22 +15,22 @@
 namespace facebook {
 namespace react {
 
-class ScrollViewShadowNode;
+extern const char ScrollViewComponentName[];
-
-using SharedScrollViewShadowNode = std::shared_ptr<const ScrollViewShadowNode>;
 
 /*
  * `ShadowNode` for <ScrollView> component.
  */
 class ScrollViewShadowNode final:
-  public ConcreteViewShadowNode<ScrollViewProps, ScrollViewEventEmitter> {
+  public ConcreteViewShadowNode<
+    ScrollViewComponentName,
+    ScrollViewProps,
+    ScrollViewEventEmitter
+  > {
 
 public:
 
   using ConcreteViewShadowNode::ConcreteViewShadowNode;
 
-  ComponentName getComponentName() const override;
-
 #pragma mark - LayoutableShadowNode
 
   void layout(LayoutContext layoutContext) override;

ReactCommon/fabric/components/switch/SwitchShadowNode.cpp

@@ -5,14 +5,12 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include <fabric/components/switch/SwitchShadowNode.h>
+#include "SwitchShadowNode.h"
 
 namespace facebook {
 namespace react {
 
-ComponentName SwitchShadowNode::getComponentName() const {
+extern const char SwitchComponentName[] = "Switch";
-  return ComponentName("Switch");
-}
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/switch/SwitchShadowNode.h

@@ -14,18 +14,17 @@
 namespace facebook {
 namespace react {
 
+extern const char SwitchComponentName[];
+
 /*
  * `ShadowNode` for <Switch> component.
  */
-class SwitchShadowNode final:
+using SwitchShadowNode =
-  public ConcreteViewShadowNode<SwitchProps, SwitchEventEmitter> {
+  ConcreteViewShadowNode<
-
+    SwitchComponentName,
-public:
+    SwitchProps,
-
+    SwitchEventEmitter
-  using ConcreteViewShadowNode::ConcreteViewShadowNode;
+  >;
-
-  ComponentName getComponentName() const override;
-};
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/text/basetext/BaseTextShadowNode.cpp

@@ -24,7 +24,7 @@ AttributedString BaseTextShadowNode::getAttributedString(
 
   for (const auto &childNode : *childNodes) {
     // RawShadowNode
-    SharedRawTextShadowNode rawTextShadowNode = std::dynamic_pointer_cast<const RawTextShadowNode>(childNode);
+    auto rawTextShadowNode = std::dynamic_pointer_cast<const RawTextShadowNode>(childNode);
     if (rawTextShadowNode) {
       AttributedString::Fragment fragment;
       fragment.string = rawTextShadowNode->getProps()->text;
@@ -34,7 +34,7 @@ AttributedString BaseTextShadowNode::getAttributedString(
     }
 
     // TextShadowNode
-    SharedTextShadowNode textShadowNode = std::dynamic_pointer_cast<const TextShadowNode>(childNode);
+    auto textShadowNode = std::dynamic_pointer_cast<const TextShadowNode>(childNode);
     if (textShadowNode) {
       TextAttributes localTextAttributes = textAttributes;
       localTextAttributes.apply(textShadowNode->getProps()->textAttributes);

ReactCommon/fabric/components/text/paragraph/ParagraphComponentDescriptor.h

@@ -30,7 +30,7 @@ public:
   }
 
   void adopt(UnsharedShadowNode shadowNode) const override {
-    ConcreteComponentDescriptor<ParagraphShadowNode>::adopt(shadowNode);
+    ConcreteComponentDescriptor::adopt(shadowNode);
 
     assert(std::dynamic_pointer_cast<ParagraphShadowNode>(shadowNode));
     auto paragraphShadowNode = std::static_pointer_cast<ParagraphShadowNode>(shadowNode);

ReactCommon/fabric/components/text/paragraph/ParagraphProps.h

@@ -18,10 +18,6 @@
 namespace facebook {
 namespace react {
 
-class ParagraphProps;
-
-using SharedParagraphProps = std::shared_ptr<const ParagraphProps>;
-
 /*
  * Props of <Paragraph> component.
  * Most of the props are directly stored in composed `ParagraphAttributes`

ReactCommon/fabric/components/text/paragraph/ParagraphShadowNode.cpp

@@ -7,16 +7,12 @@
 
 #include "ParagraphShadowNode.h"
 
-#include <fabric/debug/DebugStringConvertibleItem.h>
+#include "ParagraphLocalData.h"
-
-#import "ParagraphLocalData.h"
 
 namespace facebook {
 namespace react {
 
-ComponentName ParagraphShadowNode::getComponentName() const {
+const char ParagraphComponentName[] = "Paragraph";
-  return ComponentName("Paragraph");
-}
 
 AttributedString ParagraphShadowNode::getAttributedString() const {
   if (!cachedAttributedString_.has_value()) {
@@ -53,7 +49,7 @@ Size ParagraphShadowNode::measure(LayoutConstraints layoutConstraints) const {
 
 void ParagraphShadowNode::layout(LayoutContext layoutContext) {
   updateLocalData();
-  ConcreteViewShadowNode<ParagraphProps>::layout(layoutContext);
+  ConcreteViewShadowNode::layout(layoutContext);
 }
 
 } // namespace react

ReactCommon/fabric/components/text/paragraph/ParagraphShadowNode.h

@@ -19,9 +19,7 @@
 namespace facebook {
 namespace react {
 
-class ParagraphShadowNode;
+extern const char ParagraphComponentName[];
-
-using SharedParagraphShadowNode = std::shared_ptr<const ParagraphShadowNode>;
 
 /*
  * `ShadowNode` for <Paragraph> component, represents <View>-like component
@@ -29,15 +27,16 @@ using SharedParagraphShadowNode = std::shared_ptr<const ParagraphShadowNode>;
  * and <RawText> components.
  */
 class ParagraphShadowNode:
-  public ConcreteViewShadowNode<ParagraphProps>,
+  public ConcreteViewShadowNode<
+    ParagraphComponentName,
+    ParagraphProps
+  >,
   public BaseTextShadowNode {
 
 public:
 
   using ConcreteViewShadowNode::ConcreteViewShadowNode;
 
-  ComponentName getComponentName() const override;
-
   /*
    * Returns a `AttributedString` which represents text content of the node.
    */

ReactCommon/fabric/components/text/rawtext/RawTextProps.h

@@ -23,7 +23,6 @@ class RawTextProps:
   public Props {
 
 public:
-
   RawTextProps() = default;
   RawTextProps(const RawTextProps &sourceProps, const RawProps &rawProps);
 

ReactCommon/fabric/components/text/rawtext/RawTextShadowNode.cpp

@@ -7,14 +7,10 @@
 
 #include "RawTextShadowNode.h"
 
-#include <fabric/debug/DebugStringConvertibleItem.h>
-
 namespace facebook {
 namespace react {
 
-ComponentName RawTextShadowNode::getComponentName() const {
+extern const char RawTextComponentName[] = "RawText";
-  return ComponentName("RawText");
-}
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/text/rawtext/RawTextShadowNode.h

@@ -7,18 +7,13 @@
 
 #pragma once
 
-#include <memory>
-
 #include <fabric/components/text/RawTextProps.h>
 #include <fabric/core/ConcreteShadowNode.h>
-#include <fabric/core/ShadowNode.h>
 
 namespace facebook {
 namespace react {
 
-class RawTextShadowNode;
+extern const char RawTextComponentName[];
-
-using SharedRawTextShadowNode = std::shared_ptr<const RawTextShadowNode>;
 
 /*
  * `ShadowNode` for <RawText> component, represents a purely regular string
@@ -26,14 +21,11 @@ using SharedRawTextShadowNode = std::shared_ptr<const RawTextShadowNode>;
  * is represented as `<RawText text="Hello!"/>`.
  * <RawText> component must not have any children.
  */
-class RawTextShadowNode:
+using RawTextShadowNode =
-  public ConcreteShadowNode<RawTextProps> {
+  ConcreteShadowNode<
-
+    RawTextComponentName,
-public:
+    RawTextProps
-  using ConcreteShadowNode::ConcreteShadowNode;
+  >;
-
-  ComponentName getComponentName() const override;
-};
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/text/text/TextProps.h

@@ -16,16 +16,11 @@
 namespace facebook {
 namespace react {
 
-class TextProps;
-
-using SharedTextProps = std::shared_ptr<const TextProps>;
-
 class TextProps:
   public Props,
   public BaseTextProps {
 
 public:
-
   TextProps() = default;
   TextProps(const TextProps &sourceProps, const RawProps &rawProps);
 

ReactCommon/fabric/components/text/text/TextShadowNode.cpp

@@ -7,14 +7,10 @@
 
 #include "TextShadowNode.h"
 
-#include <fabric/debug/DebugStringConvertibleItem.h>
-
 namespace facebook {
 namespace react {
 
-ComponentName TextShadowNode::getComponentName() const {
+extern const char TextComponentName[] = "Text";
-  return ComponentName("Text");
-}
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/text/text/TextShadowNode.h

@@ -7,30 +7,25 @@
 
 #pragma once
 
-#include <fabric/attributedstring/AttributedString.h>
-#include <fabric/attributedstring/TextAttributes.h>
 #include <fabric/components/text/BaseTextShadowNode.h>
 #include <fabric/components/text/TextProps.h>
-#include <fabric/components/text/TextShadowNode.h>
 #include <fabric/core/ConcreteShadowNode.h>
-#include <fabric/core/ShadowNode.h>
 
 namespace facebook {
 namespace react {
 
-class TextShadowNode;
+extern const char TextComponentName[];
-
-using SharedTextShadowNode = std::shared_ptr<const TextShadowNode>;
 
 class TextShadowNode:
-  public ConcreteShadowNode<TextProps>,
+  public ConcreteShadowNode<
+    TextComponentName,
+    TextProps
+  >,
   public BaseTextShadowNode {
 
 public:
 
   using ConcreteShadowNode::ConcreteShadowNode;
-
-  ComponentName getComponentName() const override;
 };
 
 } // namespace react

ReactCommon/fabric/components/view/ConcreteViewShadowNode.h

@@ -24,9 +24,17 @@ namespace react {
  * as <View> and similar basic behaviour).
  * For example: <Paragraph>, <Image>, but not <Text>, <RawText>.
  */
-template <typename ViewPropsT = ViewProps, typename ViewEventEmitterT = ViewEventEmitter>
+template <
+  const char *concreteComponentName,
+  typename ViewPropsT = ViewProps,
+  typename ViewEventEmitterT = ViewEventEmitter
+>
 class ConcreteViewShadowNode:
-  public ConcreteShadowNode<ViewPropsT, ViewEventEmitterT>,
+  public ConcreteShadowNode<
+    concreteComponentName,
+    ViewPropsT,
+    ViewEventEmitterT
+  >,
   public AccessibleShadowNode,
   public YogaLayoutableShadowNode {
 
@@ -50,7 +58,7 @@ public:
     const SharedShadowNodeSharedList &children,
     const ShadowNodeCloneFunction &cloneFunction
   ):
-    ConcreteShadowNode<ViewPropsT, ViewEventEmitterT>(
+    ConcreteShadowNode<concreteComponentName, ViewPropsT, ViewEventEmitterT>(
       tag,
       rootTag,
       props,
@@ -64,7 +72,7 @@ public:
     YogaLayoutableShadowNode() {
 
     YogaLayoutableShadowNode::setProps(*props);
-    YogaLayoutableShadowNode::setChildren(ConcreteShadowNode<ViewPropsT, ViewEventEmitterT>::template getChildrenSlice<YogaLayoutableShadowNode>());
+    YogaLayoutableShadowNode::setChildren(ConcreteShadowNode<concreteComponentName, ViewPropsT, ViewEventEmitterT>::template getChildrenSlice<YogaLayoutableShadowNode>());
   };
 
   ConcreteViewShadowNode(
@@ -73,7 +81,7 @@ public:
     const SharedConcreteViewEventEmitter &eventEmitter,
     const SharedShadowNodeSharedList &children
   ):
-    ConcreteShadowNode<ViewPropsT, ViewEventEmitterT>(
+    ConcreteShadowNode<concreteComponentName, ViewPropsT, ViewEventEmitterT>(
       shadowNode,
       props,
       eventEmitter,
@@ -92,7 +100,7 @@ public:
     }
 
     if (children) {
-      YogaLayoutableShadowNode::setChildren(ConcreteShadowNode<ViewPropsT, ViewEventEmitterT>::template getChildrenSlice<YogaLayoutableShadowNode>());
+      YogaLayoutableShadowNode::setChildren(ConcreteShadowNode<concreteComponentName, ViewPropsT, ViewEventEmitterT>::template getChildrenSlice<YogaLayoutableShadowNode>());
     }
   };
 

ReactCommon/fabric/components/view/ViewProps.h

@@ -27,7 +27,6 @@ class ViewProps:
   public AccessibilityProps {
 
 public:
-
   ViewProps() = default;
   ViewProps(const YGStyle &yogaStyle);
   ViewProps(const ViewProps &sourceProps, const RawProps &rawProps);

ReactCommon/fabric/components/view/ViewShadowNode.cpp

@@ -10,9 +10,7 @@
 namespace facebook {
 namespace react {
 
-ComponentName ViewShadowNode::getComponentName() const {
+const char ViewComponentName[] = "View";
-  return ComponentName("View");
-}
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/view/ViewShadowNode.h

@@ -7,27 +7,20 @@
 
 #pragma once
 
-#include <memory>
-
 #include <fabric/components/view/ViewProps.h>
 #include <fabric/components/view/ConcreteViewShadowNode.h>
 
 namespace facebook {
 namespace react {
 
-class ViewShadowNode;
+extern const char ViewComponentName[];
 
-using SharedViewShadowNode = std::shared_ptr<const ViewShadowNode>;
+using ViewShadowNode =
-
+  ConcreteViewShadowNode<
-class ViewShadowNode final:
+    ViewComponentName,
-  public ConcreteViewShadowNode<ViewProps, ViewEventEmitter> {
+    ViewProps,
-
+    ViewEventEmitter
-public:
+  >;
-
-  using ConcreteViewShadowNode::ConcreteViewShadowNode;
-
-  ComponentName getComponentName() const override;
-};
 
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/core/componentdescriptor/ConcreteComponentDescriptor.h

@@ -37,22 +37,11 @@ public:
     eventDispatcher_(eventDispatcher) {}
 
   ComponentHandle getComponentHandle() const override {
-    return typeid(ShadowNodeT).hash_code();
+    return ShadowNodeT::Handle();
   }
 
   ComponentName getComponentName() const override {
-    // Even if this looks suboptimal, it is the only way to call
+    return ShadowNodeT::Name();
-    // a virtual non-static method of `ShadowNodeT`.
-    // Because it is not a hot path (it is executed once per an app run),
-    // it's fine.
-    return std::make_shared<ShadowNodeT>(
-      0,
-      0,
-      std::make_shared<const ConcreteProps>(),
-      nullptr,
-      ShadowNode::emptySharedShadowNodeSharedList(),
-      nullptr
-    )->ShadowNodeT::getComponentName();
   }
 
   SharedShadowNode createShadowNode(
@@ -74,6 +63,7 @@ public:
     );
 
     adopt(shadowNode);
+
     return shadowNode;
   }
 
@@ -123,6 +113,7 @@ protected:
 
   virtual void adopt(UnsharedShadowNode shadowNode) const {
     // Default implementation does nothing.
+    assert(shadowNode->getComponentHandle() == getComponentHandle());
   }
 
 private:

ReactCommon/fabric/core/primitives/ReactPrimitives.h

@@ -35,7 +35,7 @@ using SharedRawProps = std::shared_ptr<const RawProps>;
  * Practically, it's something that concrete ShadowNode and concrete
  * ComponentDescriptor have in common.
  */
-using ComponentHandle = size_t;
+using ComponentHandle = int64_t;
 
 /*
  * String identifier for components used for addressing them from

ReactCommon/fabric/core/shadownode/ConcreteShadowNode.h

@@ -19,7 +19,11 @@ namespace react {
  * `ConcreteShadowNode` is a default implementation of `ShadowNode` interface
  * with many handy features.
  */
-template <typename PropsT, typename EventEmitterT = EventEmitter>
+template <
+  const char *concreteComponentName,
+  typename PropsT,
+  typename EventEmitterT = EventEmitter
+>
 class ConcreteShadowNode: public ShadowNode {
   static_assert(std::is_base_of<Props, PropsT>::value, "PropsT must be a descendant of Props");
 
@@ -30,6 +34,14 @@ public:
   using SharedConcreteEventEmitter = std::shared_ptr<const EventEmitterT>;
   using SharedConcreteShadowNode = std::shared_ptr<const ConcreteShadowNode>;
 
+  static ComponentName Name() {
+    return ComponentName(concreteComponentName);
+  }
+
+  static ComponentHandle Handle() {
+    return ComponentHandle(concreteComponentName);
+  }
+
   static SharedConcreteProps Props(const RawProps &rawProps, const SharedProps &baseProps = nullptr) {
     return std::make_shared<const PropsT>(baseProps ? *std::static_pointer_cast<const PropsT>(baseProps) : PropsT(), rawProps);
   }
@@ -69,8 +81,12 @@ public:
       children
     ) {}
 
-  virtual ComponentHandle getComponentHandle() const {
+  ComponentName getComponentName() const override {
-    return typeid(*this).hash_code();
+    return ComponentName(concreteComponentName);
+  }
+
+  ComponentHandle getComponentHandle() const override {
+    return reinterpret_cast<ComponentHandle>(concreteComponentName);
   }
 
   const SharedConcreteProps getProps() const {

ReactCommon/fabric/core/tests/ComponentDescriptorTest.cpp

@@ -14,7 +14,8 @@ using namespace facebook::react;
 TEST(ComponentDescriptorTest, createShadowNode) {
   SharedComponentDescriptor descriptor = std::make_shared<TestComponentDescriptor>(nullptr);
 
-  ASSERT_EQ(descriptor->getComponentHandle(), typeid(TestShadowNode).hash_code());
+  ASSERT_EQ(descriptor->getComponentHandle(), TestShadowNode::Handle());
+  ASSERT_STREQ(descriptor->getComponentName().c_str(), TestShadowNode::Name().c_str());
   ASSERT_STREQ(descriptor->getComponentName().c_str(), "Test");
 
   RawProps raw;
@@ -22,7 +23,8 @@ TEST(ComponentDescriptorTest, createShadowNode) {
   SharedProps props = descriptor->cloneProps(nullptr, raw);
   SharedShadowNode node = descriptor->createShadowNode(9, 1, descriptor->createEventEmitter(0, 9), props);
 
-  ASSERT_EQ(node->getComponentHandle(), typeid(TestShadowNode).hash_code());
+  ASSERT_EQ(node->getComponentHandle(), TestShadowNode::Handle());
+  ASSERT_STREQ(node->getComponentName().c_str(), TestShadowNode::Name().c_str());
   ASSERT_STREQ(node->getComponentName().c_str(), "Test");
   ASSERT_EQ(node->getTag(), 9);
   ASSERT_EQ(node->getRootTag(), 1);
@@ -38,7 +40,6 @@ TEST(ComponentDescriptorTest, cloneShadowNode) {
   SharedShadowNode node = descriptor->createShadowNode(9, 1, descriptor->createEventEmitter(0, 9), props);
   SharedShadowNode cloned = descriptor->cloneShadowNode(node);
 
-  ASSERT_EQ(cloned->getComponentHandle(), typeid(TestShadowNode).hash_code());
   ASSERT_STREQ(cloned->getComponentName().c_str(), "Test");
   ASSERT_EQ(cloned->getTag(), 9);
   ASSERT_EQ(cloned->getRootTag(), 1);

ReactCommon/fabric/core/tests/ShadowNodeTest.cpp

@@ -35,8 +35,6 @@ TEST(ShadowNodeTest, handleShadowNodeCreation) {
   ASSERT_EQ(node->getTag(), 9);
   ASSERT_EQ(node->getRootTag(), 1);
   ASSERT_EQ(node->getEventEmitter(), nullptr);
-  TestShadowNode *nodePtr = node.get();
-  ASSERT_EQ(node->getComponentHandle(), typeid(*nodePtr).hash_code());
   ASSERT_EQ(node->getChildren()->size(), 0);
 
   ASSERT_STREQ(node->getProps()->nativeId.c_str(), "testNativeID");

ReactCommon/fabric/core/tests/TestComponent.h

@@ -36,6 +36,8 @@ private:
   int number_ {0};
 };
 
+static const char TestComponentName[] = "Test";
+
 class TestProps : public Props {
 public:
   using Props::Props;
@@ -46,21 +48,12 @@ using SharedTestProps = std::shared_ptr<const TestProps>;
 
 class TestShadowNode;
 using SharedTestShadowNode = std::shared_ptr<const TestShadowNode>;
-class TestShadowNode : public ConcreteShadowNode<TestProps> {
+class TestShadowNode : public ConcreteShadowNode<TestComponentName, TestProps> {
 public:
   using ConcreteShadowNode::ConcreteShadowNode;
-
-  ComponentName getComponentName() const override {
-    return ComponentName("Test");
-  }
 };
 
 class TestComponentDescriptor: public ConcreteComponentDescriptor<TestShadowNode> {
 public:
   using ConcreteComponentDescriptor::ConcreteComponentDescriptor;
-
-  // TODO (shergin): Why does this gets repeated here and the shadow node class?
-  ComponentName getComponentName() const override {
-    return "Test";
-  }
 };