Add YogaConfig unit tests

Summary:
- depends on #497
Closes https://github.com/facebook/yoga/pull/498

Reviewed By: emilsjolander

Differential Revision: D4796199

Pulled By: splhack

fbshipit-source-id: c63f23da11a719b36c0d49e954b29c0016cad8c7

csharp/tests/Facebook.Yoga/YogaConfigTest.cs

@@ -0,0 +1,136 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+using NUnit.Framework;
+using System;
+
+/**
+ * Tests for {@link YogaConfig}.
+ */
+namespace Facebook.Yoga
+{
+    [TestFixture]
+    public class YogaConfigTest
+    {
+        [Test]
+        public void TestUseWebDefaults()
+        {
+            YogaNode node0 = new YogaNode(new YogaConfig{UseWebDefaults = true});
+            Assert.AreEqual(YogaFlexDirection.Row, node0.FlexDirection);
+
+            node0.Reset();
+            Assert.AreEqual(YogaFlexDirection.Row, node0.FlexDirection);
+
+            YogaConfig config = new YogaConfig();
+            config.UseWebDefaults = true;
+            YogaNode node1 = new YogaNode(config);
+            Assert.AreEqual(YogaFlexDirection.Row, node1.FlexDirection);
+
+            node1.Reset();
+            Assert.AreEqual(YogaFlexDirection.Row, node1.FlexDirection);
+        }
+
+        [Test]
+        public void TestDefaultConfig()
+        {
+            YogaNode node0 = new YogaNode();
+            Assert.AreEqual(YogaFlexDirection.Column, node0.FlexDirection);
+
+            YogaNode node1 = new YogaNode(new YogaConfig());
+            Assert.AreEqual(YogaFlexDirection.Column, node1.FlexDirection);
+        }
+
+        [Test]
+        public void TestCopyConstructor()
+        {
+            YogaNode srcNode = new YogaNode(new YogaConfig{UseWebDefaults = true});
+            YogaNode node0 = new YogaNode(srcNode);
+            Assert.AreEqual(YogaFlexDirection.Row, node0.FlexDirection);
+
+            node0.FlexDirection = YogaFlexDirection.Column;
+            Assert.AreEqual(YogaFlexDirection.Column, node0.FlexDirection);
+
+            node0.Reset();
+            Assert.AreEqual(YogaFlexDirection.Row, node0.FlexDirection);
+
+            YogaNode node1 = new YogaNode(srcNode)
+            {
+                FlexDirection = YogaFlexDirection.Column
+            };
+            Assert.AreEqual(YogaFlexDirection.Column, node1.FlexDirection);
+
+            node1.Reset();
+            Assert.AreEqual(YogaFlexDirection.Row, node1.FlexDirection);
+        }
+
+        public static void ForceGC()
+        {
+            YogaNodeTest.ForceGC();
+        }
+
+        [Test]
+        public void TestDestructor()
+        {
+            ForceGC();
+            int instanceCount = YogaConfig.GetInstanceCount();
+            TestDestructorForGC(instanceCount);
+            ForceGC();
+            Assert.AreEqual(instanceCount, YogaConfig.GetInstanceCount());
+        }
+
+        private void TestDestructorForGC(int instanceCount)
+        {
+            YogaConfig config = new YogaConfig();
+            Assert.IsNotNull(config);
+            Assert.AreEqual(instanceCount + 1, YogaConfig.GetInstanceCount());
+            config = null;
+        }
+
+        [Test]
+        public void TestRetainConfig()
+        {
+            ForceGC();
+            int nodeInstanceCount = YogaNode.GetInstanceCount();
+            int configInstanceCount = YogaConfig.GetInstanceCount();
+            TestRetainConfigForGC(nodeInstanceCount, configInstanceCount);
+            ForceGC();
+
+            Assert.AreEqual(nodeInstanceCount, YogaNode.GetInstanceCount());
+            Assert.AreEqual(configInstanceCount, YogaConfig.GetInstanceCount());
+        }
+
+        private void TestRetainConfigForGC(int nodeInstanceCount, int configInstanceCount)
+        {
+            ForceGC();
+            Assert.AreEqual(nodeInstanceCount, YogaNode.GetInstanceCount());
+            Assert.AreEqual(configInstanceCount, YogaConfig.GetInstanceCount());
+            YogaNode node = TestRetainConfigForGC2(nodeInstanceCount, configInstanceCount);
+            ForceGC();
+            Assert.IsNotNull(node);
+            Assert.AreEqual(configInstanceCount + 1, YogaConfig.GetInstanceCount());
+            Assert.AreEqual(nodeInstanceCount + 1, YogaNode.GetInstanceCount());
+            node = null;
+        }
+
+        private YogaNode TestRetainConfigForGC2(int nodeInstanceCount, int configInstanceCount)
+        {
+            YogaConfig config = new YogaConfig();
+            Assert.IsNotNull(config);
+            Assert.AreEqual(configInstanceCount + 1, YogaConfig.GetInstanceCount());
+
+            YogaNode node = new YogaNode(config);
+            Assert.IsNotNull(node);
+            Assert.AreEqual(nodeInstanceCount + 1, YogaNode.GetInstanceCount());
+
+            config = null;
+
+            return node;
+        }
+    }
+}