Add test utilities for C++ and Java

Summary:
@public

Test utility on top of the new event system that maintains a counter of instantiated nodes. Meant to replace the global node counter.

Reviewed By: SidharthGuglani

Differential Revision: D15174855

fbshipit-source-id: 6998472f95a09b8da652257a26596164bdcf43d6

BUCK

@@ -56,6 +56,7 @@ yoga_cxx_test(
     visibility = ["PUBLIC"],
     deps = [
         ":yogaForDebug",
+        yoga_dep("testutil:testutil"),
         GTEST_TARGET,
     ],
 )

java/BUCK

@@ -3,7 +3,12 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 
-load("//tools/build_defs/oss:yoga_defs.bzl", "ANDROID", "CXX_LIBRARY_WHITELIST", "FBJNI_JAVA_TARGET", "FBJNI_TARGET", "INFER_ANNOTATIONS_TARGET", "JNI_TARGET", "JSR_305_TARGET", "JUNIT_TARGET", "PROGRUARD_ANNOTATIONS_TARGET", "SOLOADER_TARGET", "yoga_cxx_library", "yoga_dep", "yoga_java_binary", "yoga_java_library", "yoga_java_test")
+load("//tools/build_defs/oss:yoga_defs.bzl", "ANDROID", "CXX_LIBRARY_WHITELIST", "FBJNI_JAVA_TARGET", "FBJNI_TARGET", "INFER_ANNOTATIONS_TARGET", "JNI_TARGET", "JSR_305_TARGET", "JUNIT_TARGET", "PROGRUARD_ANNOTATIONS_TARGET", "SOLOADER_TARGET", "yoga_cxx_lib", "yoga_cxx_library", "yoga_dep", "yoga_java_binary", "yoga_java_library", "yoga_java_test")
+
+CXX_LIBRARY_WHITELIST_FOR_TESTS = CXX_LIBRARY_WHITELIST + [
+    yoga_cxx_lib("testutil:jni"),
+    yoga_cxx_lib("testutil:testutil"),
+]
 
 yoga_cxx_library(
     name = "jni",
@@ -55,11 +60,12 @@ yoga_java_library(
 yoga_java_test(
     name = "tests",
     srcs = glob(["tests/**/*.java"]),
-    cxx_library_whitelist = CXX_LIBRARY_WHITELIST,
+    cxx_library_whitelist = CXX_LIBRARY_WHITELIST_FOR_TESTS,
     use_cxx_libraries = True,
     visibility = ["PUBLIC"],
     deps = [
         ":java",
+        yoga_dep("testutil:java"),
         JUNIT_TARGET,
     ],
 )

tests/EventsTest.cpp

@@ -8,6 +8,7 @@
 #include <yoga/Yoga.h>
 #include <yoga/events.h>
 #include <yoga/YGNode.h>
+#include <yoga/testutil/testutil.h>
 
 #include <functional>
 #include <memory>
@@ -27,9 +28,12 @@ struct EventArgs {
   }
 };
 
-struct EventTest : public ::testing::Test {
+class EventTest : public ::testing::Test {
+  ScopedEventSubscription subscription = {&EventTest::listen};
+  static void listen(const YGNode&, Event::Type, Event::Data);
+
+public:
   static EventArgs lastEvent;
-  static void SetUpTestCase() noexcept;
 };
 
 TEST_F(EventTest, new_node_has_event) {
@@ -92,23 +96,15 @@ EventArgs createArgs(const YGNode& node, const Event::Data& data) {
 
 } // namespace
 
-void EventTest::SetUpTestCase() noexcept {
-  static bool isSetup = false;
-  if (isSetup) {
-    return;
+void EventTest::listen(const YGNode& node, Event::Type type, Event::Data data) {
+  switch (type) {
+    case Event::NodeAllocation:
+      lastEvent = createArgs<Event::NodeAllocation>(node, data);
+      break;
+    case Event::NodeDeallocation:
+      lastEvent = createArgs<Event::NodeDeallocation>(node, data);
+      break;
   }
-  isSetup = true;
-
-  Event::subscribe([](const YGNode& node, Event::Type type, Event::Data data) {
-    switch (type) {
-      case Event::NodeAllocation:
-        lastEvent = createArgs<Event::NodeAllocation>(node, data);
-        break;
-      case Event::NodeDeallocation:
-        lastEvent = createArgs<Event::NodeDeallocation>(node, data);
-        break;
-    }
-  });
 }
 
 EventArgs EventTest::lastEvent{};

testutil/BUCK

@@ -0,0 +1,37 @@
+load("//tools/build_defs/oss:yoga_defs.bzl", "ANDROID", "FBJNI_TARGET", "LIBRARY_COMPILER_FLAGS", "SOLOADER_TARGET", "yoga_cxx_library", "yoga_dep", "yoga_java_library")
+
+yoga_cxx_library(
+    name = "testutil",
+    srcs = ["testutil.cpp"],
+    header_namespace = "yoga/testutil",
+    exported_headers = ["testutil.h"],
+    compiler_flags = LIBRARY_COMPILER_FLAGS,
+    soname = "libyoga_testutil.$(ext)",
+    visibility = ["PUBLIC"],
+    deps = [yoga_dep(":yoga")],
+)
+
+yoga_java_library(
+    name = "java",
+    srcs = ["TestUtil.java"],
+    source = "1.7",
+    target = "1.7",
+    visibility = ["PUBLIC"],
+    deps = [
+        ":jni",
+        SOLOADER_TARGET,
+    ],
+)
+
+yoga_cxx_library(
+    name = "jni",
+    srcs = ["jni.cpp"],
+    compiler_flags = LIBRARY_COMPILER_FLAGS,
+    platforms = ANDROID,
+    soname = "libyoga_testutil_jni.$(ext)",
+    visibility = ["PUBLIC"],
+    deps = [
+        ":testutil",
+        FBJNI_TARGET,
+    ],
+)

testutil/TestUtil.java

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+package com.facebook.yoga;
+
+import com.facebook.soloader.SoLoader;
+
+class TestUtil {
+  static {
+    SoLoader.loadLibrary("yoga_testutil_jni");
+  }
+
+  static native void startCountingNodes();
+  static native int nodeCount();
+  static native int stopCountingNodes();
+}

testutil/jni.cpp

@@ -0,0 +1,38 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include <fb/fbjni.h>
+#include <yoga/testutil/testutil.h>
+
+using namespace facebook;
+
+namespace {
+
+void startCountingNodes(jni::alias_ref<jclass>) {
+  yoga::test::TestUtil::startCountingNodes();
+}
+
+jint nodeCount(jni::alias_ref<jclass>) {
+  return yoga::test::TestUtil::nodeCount();
+}
+
+jint stopCountingNodes(jni::alias_ref<jclass>) {
+  return yoga::test::TestUtil::stopCountingNodes();
+}
+
+} // namespace
+
+jint JNI_OnLoad(JavaVM* vm, void*) {
+  return jni::initialize(vm, [] {
+    jni::registerNatives(
+        "com/facebook/yoga/TestUtil",
+        {
+            makeNativeMethod("startCountingNodes", startCountingNodes),
+            makeNativeMethod("nodeCount", nodeCount),
+            makeNativeMethod("stopCountingNodes", stopCountingNodes),
+        });
+  });
+}

testutil/testutil.cpp

@@ -0,0 +1,65 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#include "testutil.h"
+
+#include <yoga/YGNode.h>
+#include <yoga/events.h>
+
+#include <utility>
+
+namespace facebook {
+namespace yoga {
+namespace test {
+
+int nodeInstanceCount = 0;
+
+namespace {
+
+void yogaEventSubscriber(
+    const YGNode& node,
+    Event::Type eventType,
+    const Event::Data& eventData) {
+
+  switch (eventType) {
+    case Event::NodeAllocation:
+      nodeInstanceCount++;
+      break;
+    case Event::NodeDeallocation:
+      nodeInstanceCount--;
+      break;
+    default:
+      break;
+  }
+}
+} // namespace
+
+void TestUtil::startCountingNodes() {
+  nodeInstanceCount = 0;
+  Event::subscribe(yogaEventSubscriber);
+}
+
+int TestUtil::nodeCount() {
+  return nodeInstanceCount;
+}
+
+int TestUtil::stopCountingNodes() {
+  Event::reset();
+  return std::exchange(nodeInstanceCount, 0);
+}
+
+ScopedEventSubscription::ScopedEventSubscription(
+    std::function<Event::Subscriber>&& s) {
+  Event::subscribe(std::move(s));
+}
+
+ScopedEventSubscription::~ScopedEventSubscription() {
+  Event::reset();
+}
+
+} // namespace test
+} // namespace yoga
+} // namespace facebook

testutil/testutil.h

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the LICENSE
+ * file in the root directory of this source tree.
+ */
+#pragma once
+
+#include <yoga/events.h>
+
+#include <functional>
+
+namespace facebook {
+namespace yoga {
+namespace test {
+
+struct TestUtil {
+  static void startCountingNodes();
+  static int nodeCount();
+  static int stopCountingNodes();
+};
+
+struct ScopedEventSubscription {
+  ScopedEventSubscription(std::function<Event::Subscriber>&&);
+  ~ScopedEventSubscription();
+};
+
+} // namespace test
+} // namespace yoga
+} // namespace facebook

tools/build_defs/oss/yoga_defs.bzl

@@ -148,6 +148,9 @@ def _single_subdir_glob(dirpath, glob_pattern, exclude = None, prefix = None):
 def yoga_dep(dep):
     return "//" + dep
 
+def yoga_cxx_lib(lib):
+    return yoga_dep(lib)
+
 def yoga_android_aar(*args, **kwargs):
     native.android_aar(*args, **kwargs)
 

yoga/events.cpp

@@ -24,6 +24,10 @@ std::function<Event::Subscriber>& globalEventSubscriber() {
 
 } // namespace
 
+void Event::reset() {
+  globalEventSubscriber() = nullptr;
+}
+
 void Event::subscribe(std::function<Subscriber>&& subscriber) {
   if (globalEventSubscriber() != nullptr) {
     throw std::logic_error(

yoga/events.h

@@ -35,6 +35,8 @@ struct Event {
     };
   };
 
+  static void reset();
+
   static void subscribe(std::function<Subscriber>&& subscriber);
 
   template <Type E>