xplat/js/react-native-github/packages/react-native/ReactCommon/yoga/yoga/event/event.cpp

tests/EventPublisherTest.cpp

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+/*
+ * 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 <yoga/Yoga.h>
+#include <yoga/event/event.h>
+
+#include <array>
+#include <string_view>
+#include <unordered_set>
+
+namespace facebook::yoga::test {
+
+// Every enum value declared in LayoutPassReason (excluding the COUNT sentinel).
+// Kept in sync with yoga/event/event.h; a missing entry causes the "all known
+// reasons" test to catch the omission on the next run.
+constexpr std::array<LayoutPassReason, 9> kAllKnownReasons = {
+    LayoutPassReason::kInitial,
+    LayoutPassReason::kAbsLayout,
+    LayoutPassReason::kStretch,
+    LayoutPassReason::kMultilineStretch,
+    LayoutPassReason::kFlexLayout,
+    LayoutPassReason::kMeasureChild,
+    LayoutPassReason::kAbsMeasureChild,
+    LayoutPassReason::kFlexMeasure,
+    LayoutPassReason::kGridLayout,
+};
+
+TEST(
+    LayoutPassReasonToStringTest,
+    everyKnownReasonMapsToDistinctNonUnknownLabel) {
+  std::unordered_set<std::string_view> labels;
+  for (auto reason : kAllKnownReasons) {
+    const char* label = LayoutPassReasonToString(reason);
+    ASSERT_NE(label, nullptr)
+        << "LayoutPassReasonToString returned nullptr for enum value "
+        << static_cast<int>(reason);
+    EXPECT_STRNE(label, "")
+        << "Empty label for enum value " << static_cast<int>(reason);
+    EXPECT_STRNE(label, "unknown")
+        << "Enum value " << static_cast<int>(reason)
+        << " unexpectedly fell through to the default case";
+    labels.emplace(label);
+  }
+  EXPECT_EQ(labels.size(), kAllKnownReasons.size())
+      << "At least two LayoutPassReason values share the same label";
+}
+
+TEST(LayoutPassReasonToStringTest, fallsBackToUnknownForUnrecognizedValues) {
+  // Out-of-range integer cast: exercises the switch's default branch, which
+  // guards against silent regressions when new enum values are added without
+  // updating the switch.
+  EXPECT_STREQ(
+      LayoutPassReasonToString(static_cast<LayoutPassReason>(9999)), "unknown");
+
+  // COUNT is the sentinel used to size arrays and is not a real reason, so
+  // it must also fall through to the default case.
+  EXPECT_STREQ(LayoutPassReasonToString(LayoutPassReason::COUNT), "unknown");
+}
+
+class EventPublisherTest : public ::testing::Test {
+ protected:
+  // Event maintains a process-global subscriber list; clear it around each
+  // test to keep the tests independent regardless of ordering.
+  void SetUp() override {
+    Event::reset();
+  }
+  void TearDown() override {
+    Event::reset();
+  }
+};
+
+TEST_F(
+    EventPublisherTest,
+    resetDetachesPreviouslyRegisteredSubscribersFromFutureEvents) {
+  int callCount = 0;
+  Event::subscribe(
+      [&](YGNodeConstRef, Event::Type, Event::Data) { ++callCount; });
+
+  // Sanity-check that the subscriber is actually wired up before reset.
+  Event::publish<Event::LayoutPassStart>(nullptr);
+  ASSERT_EQ(callCount, 1);
+
+  Event::reset();
+  Event::publish<Event::LayoutPassStart>(nullptr);
+  Event::publish<Event::LayoutPassEnd>(
+      nullptr, Event::TypedData<Event::LayoutPassEnd>{nullptr});
+
+  EXPECT_EQ(callCount, 1)
+      << "Subscriber should not have been invoked after Event::reset()";
+}
+
+TEST_F(EventPublisherTest, publishForwardsToEverySubscriberWithNodeAndType) {
+  YGNodeRef sentinelNode = YGNodeNew();
+
+  int subscriberACallCount = 0;
+  int subscriberBCallCount = 0;
+  YGNodeConstRef subscriberAReceivedNode = nullptr;
+  Event::Type subscriberAReceivedType = Event::NodeAllocation;
+
+  Event::subscribe([&](YGNodeConstRef node, Event::Type type, Event::Data) {
+    ++subscriberACallCount;
+    subscriberAReceivedNode = node;
+    subscriberAReceivedType = type;
+  });
+  Event::subscribe([&](YGNodeConstRef, Event::Type, Event::Data) {
+    ++subscriberBCallCount;
+  });
+
+  Event::publish<Event::LayoutPassStart>(sentinelNode);
+
+  EXPECT_EQ(subscriberACallCount, 1);
+  EXPECT_EQ(subscriberBCallCount, 1);
+  EXPECT_EQ(subscriberAReceivedNode, sentinelNode);
+  EXPECT_EQ(subscriberAReceivedType, Event::LayoutPassStart);
+
+  YGNodeFree(sentinelNode);
+}
+
+} // namespace facebook::yoga::test