Add unit tests for RootShadowNode

Summary:
Changelog: [internal]

Add unit tests to prevent bug with `RootShadowNode::clone`.

Reviewed By: mdvacca

Differential Revision: D28378456

fbshipit-source-id: 8564835e5dfe677b17111162ccad40d975615cf9

ReactCommon/react/renderer/components/root/BUCK

@@ -76,5 +76,6 @@ fb_xplat_cxx_test(
  ":root",
  "//xplat/folly:molly",
  "//xplat/third-party/gmock:gtest",
+ react_native_xplat_target("react/renderer/element:element"),
  ],
 )

ReactCommon/react/renderer/components/root/tests/RootShadowNodeTest.cpp

@@ -5,10 +5,38 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#include <memory>
+#include <react/renderer/components/root/RootComponentDescriptor.h>
+#include <react/renderer/element/ComponentBuilder.h>
+#include <react/renderer/element/Element.h>
+#include <react/renderer/element/testUtils.h>
 
 #include <gtest/gtest.h>
 
-TEST(RootShadowNodeTest, testSomething) {
- // TODO
+namespace facebook::react {
+
+TEST(RootShadowNodeTest, cloneWithLayoutConstraints) {
+ auto builder = simpleComponentBuilder();
+ std::shared_ptr<RootShadowNode> rootShadowNode;
+ LayoutConstraints defaultLayoutConstraints = {};
+
+ auto element =
+ Element<RootShadowNode>().reference(rootShadowNode).tag(1).props([&] {
+ auto sharedProps = std::make_shared<RootProps>();
+ sharedProps->layoutConstraints = defaultLayoutConstraints;
+ return sharedProps;
+ });
+
+ builder.build(element);
+
+ EXPECT_FALSE(rootShadowNode->getIsLayoutClean());
+ EXPECT_TRUE(rootShadowNode->layoutIfNeeded());
+ EXPECT_TRUE(rootShadowNode->getIsLayoutClean());
+
+ auto clonedWithDiffentLayoutConstraints =
+ rootShadowNode->clone(LayoutConstraints{{0, 0}, {10, 10}}, {});
+
+ EXPECT_FALSE(clonedWithDiffentLayoutConstraints->getIsLayoutClean());
+ EXPECT_TRUE(clonedWithDiffentLayoutConstraints->layoutIfNeeded());
 }
+
+} // namespace facebook::react