[bugfix] Fix MLA-793 Make Unity lifecycle methods protected. Added tests for changes

Project/Project.sln.DotSettings

@@ -0,0 +1,2 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=Dont/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

com.unity.ml-agents/CHANGELOG.md

@@ -42,6 +42,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
  - `AgentInfo.actionMasks` has been renamed to `AgentInfo.discreteActionMasks`.
  - `DecisionRequester` has been made internal (you can still use the DecisionRequesterComponent from the inspector). `RepeatAction` was renamed `TakeActionsBetweenDecisions` for clarity. (#3555)
  - The `IFloatProperties` interface has been removed.
+ - Fix #3579.
 
 ## [0.14.1-preview] - 2020-02-25
 

com.unity.ml-agents/Runtime/Agent.cs

@@ -215,7 +215,10 @@ public string BehaviorName  {
         /// </summary>
         internal VectorSensor collectObservationsSensor;
 
-        void OnEnable()
+        /// <summary>
+        /// Called when the attached <see cref="GameObject"/> becomes enabled and active.
+        /// </summary>
+        protected virtual void OnEnable()
         {
             LazyInitialize();
         }
@@ -299,7 +302,10 @@ enum DoneReason
             Disabled,
         }
 
-        void OnDisable()
+        /// <summary>
+        /// Called when the attached <see cref="GameObject"/> becomes disabled and inactive.
+        /// </summary>
+        protected virtual void OnDisable()
         {
             DemonstrationWriters.Clear();
 
@@ -570,6 +576,13 @@ internal void InitializeSensors()
         /// </summary>
         void SendInfoToBrain()
         {
+            if (!m_Initialized)
+            {
+                throw new UnityAgentsException("Call to SendInfoToBrain when Agent hasn't been initialized." +
+                    "Please ensure that you are calling 'base.OnEnable()' if you have overridden OnEnable.");
+
+            }
+
             if (m_Brain == null)
             {
                 return;

com.unity.ml-agents/Tests/Editor/MLAgentsEditModeTest.cs

@@ -1,3 +1,4 @@
+using System.CodeDom;
 using UnityEngine;
 using NUnit.Framework;
 using System.Reflection;
@@ -602,4 +603,61 @@ public void TestHeuristicPolicyStepsSensors()
             Assert.AreEqual(numSteps, agent1.sensor2.numCompressedCalls);
         }
     }
+
+    [TestFixture]
+    public class TestOnEnableOverride
+    {
+        public class OnEnableAgent : Agent
+        {
+            public bool callBase;
+
+            protected override void OnEnable()
+            {
+                if (callBase)
+                    base.OnEnable();
+            }
+        }
+
+        static void _InnerAgentTestOnEnableOverride(bool callBase = false)
+        {
+            var go = new GameObject();
+            var agent = go.AddComponent<OnEnableAgent>();
+            agent.callBase = callBase;
+            var onEnable = typeof(OnEnableAgent).GetMethod("OnEnable", BindingFlags.NonPublic | BindingFlags.Instance);
+            var sendInfo = typeof(Agent).GetMethod("SendInfoToBrain", BindingFlags.NonPublic | BindingFlags.Instance);
+            Assert.NotNull(onEnable);
+            onEnable.Invoke(agent, null);
+            Assert.NotNull(sendInfo);
+            if (agent.callBase)
+            {
+                Assert.DoesNotThrow(() => sendInfo.Invoke(agent, null));
+            }
+            else
+            {
+                Assert.Throws<UnityAgentsException>(() =>
+                {
+                    try
+                    {
+                        sendInfo.Invoke(agent, null);
+                    }
+                    catch (TargetInvocationException e)
+                    {
+                        throw e.GetBaseException();
+                    }
+                });
+            }
+        }
+
+        [Test]
+        public void TestAgentCallBaseOnEnable()
+        {
+            _InnerAgentTestOnEnableOverride(true);
+        }
+
+        [Test]
+        public void TestAgentDontCallBaseOnEnable()
+        {
+            _InnerAgentTestOnEnableOverride();
+        }
+    }
 }