Revert "remove keytangents test"

This reverts commit c027e2d.

Author: vkovec

Assets/com.unity.formats.fbx/EditorTests/FbxAnimationTest.cs

@@ -303,6 +303,33 @@ public virtual int Compare(Keyframe a, Keyframe b)
             }
         }
 
+        public class KeyTangentComparer : IComparer<Keyframe>
+        {
+            public int CompareKeyTangents(Keyframe a, Keyframe b)
+            {
+                bool result = true;
+
+                result &= a.time.Equals(b.time);
+                #if DEBUG_UNITTEST
+                Debug.Log(string.Format("{2} a.time: {0}, b.time: {1}", a.time, b.time,result));
+                #endif
+                // TODO : use AnimationUtility.GetLeftTangentMode 
+                // requires reference to AnimationCurve and keyindex
+                result &= (a.tangentMode == b.tangentMode);
+                #if DEBUG_UNITTEST
+                Debug.Log(string.Format("{2} a.tangentMode={0} b.tangentMode={1}", 
+                    ((AnimationUtility.TangentMode)a.tangentMode).ToString(),
+                    ((AnimationUtility.TangentMode)b.tangentMode).ToString(),result));
+                #endif
+                return result ? 0 : 1;
+            }
+
+            public int Compare(Keyframe a, Keyframe b)
+            {
+                return CompareKeyTangents(a,b);
+            }
+        }
+
         public class AnimTester
         {
             public FbxAnimationTest.KeyData keyData;
@@ -725,6 +752,30 @@ public int ContinuousRotationAnimTest (RotationCurveType rotCurveType, float []
             return tester.DoIt();
         }
 
+        [Description("Uni-35935 key tangents")]
+        [Test, TestCaseSource (typeof (AnimationTestDataClass), "KeyTangentsTestCases")]
+        public int KeyTangentsAnimTest (float [] keyTimesInSeconds, Vector3 [] keyPosValues, Vector3 [] keyRotValues)
+        {
+            System.Type componentType = typeof(Transform);
+
+            if (keyRotValues == null)
+            {
+                keyRotValues = new Vector3[keyPosValues.Length];
+            }
+                
+            string[] propertyNames = null;
+            string testName = componentType.ToString () + "_KeyTangents";
+            RotationCurveType rotCurveType = RotationCurveType.kEuler;
+                
+            testName += "_Euler";
+            propertyNames = AnimationTestDataClass.m_rotationEulerNames.Concat(AnimationTestDataClass.m_translationNames).ToArray();
+
+            KeyData keyData = new TransformKeyData { RotationType = rotCurveType, propertyNames = propertyNames, componentType = componentType, keyTimes = keyTimesInSeconds, keyPosValues = keyPosValues, keyEulerValues = keyRotValues };
+
+            var tester = new AnimTester {keyData=keyData, testName=testName, path=GetRandomFbxFilePath (), keyComparer=new KeyTangentComparer()};
+            return tester.DoIt();
+        }
+
         [Test, TestCaseSource (typeof (AnimationTestDataClass), "ComponentTestCases")]
         public int ComponentAnimTest (System.Type componentType)
         {