feat(decorators): add three new decorators

RepeatForever, RepeatUntilSuccess, and RepeatUntilFailure are new decorators used to continue a task
indefinitely.  RepeatForever executes its child and returns TaskStatus.Continue, regardless of its
child's return status.  RepeatUntilSuccess returns TaskStatus.Success if its child returns success,
else it returns TaskStatus.Continue.  RepeatUntilFailure returns TaskStatus.Failure if its child
returns failure, else it returns TaskStatus.Continue.

Author: JesseTG

Assets/FluidBehaviorTree/Runtime/BehaviorTree/Builder/BehaviorTreeBuilder.cs

@@ -62,6 +62,18 @@ public BehaviorTreeBuilder ReturnFailure (string name = "return failure") {
             return ParentTask<ReturnFailure>(name);
         }
 
+        public BehaviorTreeBuilder RepeatUntilSuccess (string name = "repeat until success") {
+            return ParentTask<RepeatUntilSuccess>(name);
+        }
+
+        public BehaviorTreeBuilder RepeatUntilFailure (string name = "repeat until failure") {
+            return ParentTask<RepeatUntilFailure>(name);
+        }
+
+        public BehaviorTreeBuilder RepeatForever (string name = "repeat forever") {
+            return ParentTask<RepeatForever>(name);
+        }
+
         public BehaviorTreeBuilder Sequence (string name = "sequence") {
             return ParentTask<Sequence>(name);
         }

Assets/FluidBehaviorTree/Runtime/Decorators/RepeatForever.cs

@@ -0,0 +1,12 @@
+using CleverCrow.Fluid.BTs.Trees;
+using CleverCrow.Fluid.BTs.Decorators;
+using CleverCrow.Fluid.BTs.Tasks;
+
+namespace CleverCrow.Fluid.BTs.Decorators {
+    public class RepeatForever : DecoratorBase {
+        protected override TaskStatus OnUpdate () {
+            Child?.Update();
+            return TaskStatus.Continue;
+        }
+    }
+}

Assets/FluidBehaviorTree/Runtime/Decorators/RepeatForever.cs.meta

@@ -0,0 +1,23 @@
+using CleverCrow.Fluid.BTs.Trees;
+using CleverCrow.Fluid.BTs.Decorators;
+using CleverCrow.Fluid.BTs.Tasks;
+
+namespace CleverCrow.Fluid.BTs.Decorators {
+    public class RepeatUntilFailure : DecoratorBase {
+        protected override TaskStatus OnUpdate () {
+            if (Child == null) {
+                return TaskStatus.Failure;
+            }
+
+            var childStatus = Child.Update();
+            var status = childStatus;
+
+            if (status == TaskStatus.Failure) {
+                return TaskStatus.Failure;
+            }
+            else {
+                return TaskStatus.Continue;
+            }
+        }
+    }
+}

Assets/FluidBehaviorTree/Runtime/Decorators/RepeatUntilFailure.cs

@@ -0,0 +1,23 @@
+using CleverCrow.Fluid.BTs.Trees;
+using CleverCrow.Fluid.BTs.Decorators;
+using CleverCrow.Fluid.BTs.Tasks;
+
+namespace CleverCrow.Fluid.BTs.Decorators {
+    public class RepeatUntilSuccess : DecoratorBase {
+        protected override TaskStatus OnUpdate () {
+            if (Child == null) {
+                return TaskStatus.Success;
+            }
+
+            var childStatus = Child.Update();
+            var status = childStatus;
+
+            if (status == TaskStatus.Success) {
+                return TaskStatus.Success;
+            }
+            else {
+                return TaskStatus.Continue;
+            }
+        }
+    }
+}

Assets/FluidBehaviorTree/Runtime/Decorators/RepeatUntilFailure.cs.meta

@@ -0,0 +1,40 @@
+using CleverCrow.Fluid.BTs.Decorators;
+using CleverCrow.Fluid.BTs.Tasks;
+using NUnit.Framework;
+
+namespace CleverCrow.Fluid.BTs.Testing {
+    public class RepeatForeverTest {
+        public class UpdateMethod {
+            [Test]
+            public void Returns_continue_on_child_failure () {
+                var repeater = new RepeatForever();
+                repeater.AddChild(A.TaskStub().WithUpdateStatus(TaskStatus.Failure).Build());
+
+                Assert.AreEqual(TaskStatus.Continue, repeater.Update());
+            }
+
+            [Test]
+            public void Returns_continue_on_child_success () {
+                var repeater = new RepeatForever();
+                repeater.AddChild(A.TaskStub().WithUpdateStatus(TaskStatus.Success).Build());
+
+                Assert.AreEqual(TaskStatus.Continue, repeater.Update());
+            }
+
+            [Test]
+            public void Returns_continue_on_child_continue () {
+                var repeater = new RepeatForever();
+                repeater.AddChild(A.TaskStub().WithUpdateStatus(TaskStatus.Continue).Build());
+
+                Assert.AreEqual(TaskStatus.Continue, repeater.Update());
+            }
+
+            [Test]
+            public void Does_not_crash_if_no_child () {
+                var repeater = new RepeatForever();
+
+                Assert.DoesNotThrow(() => repeater.Update());
+            }
+        }
+    }
+}

Assets/FluidBehaviorTree/Runtime/Decorators/RepeatUntilSuccess.cs

@@ -0,0 +1,40 @@
+using CleverCrow.Fluid.BTs.Decorators;
+using CleverCrow.Fluid.BTs.Tasks;
+using NUnit.Framework;
+
+namespace CleverCrow.Fluid.BTs.Testing {
+    public class RepeatUntilFailureTest {
+        public class UpdateMethod {
+            [Test]
+            public void Returns_failure_on_child_failure () {
+                var repeater = new RepeatUntilFailure();
+                repeater.AddChild(A.TaskStub().WithUpdateStatus(TaskStatus.Failure).Build());
+
+                Assert.AreEqual(TaskStatus.Failure, repeater.Update());
+            }
+
+            [Test]
+            public void Returns_continue_on_child_success () {
+                var repeater = new RepeatUntilFailure();
+                repeater.AddChild(A.TaskStub().WithUpdateStatus(TaskStatus.Success).Build());
+
+                Assert.AreEqual(TaskStatus.Continue, repeater.Update());
+            }
+
+            [Test]
+            public void Returns_continue_on_child_continue () {
+                var repeater = new RepeatUntilFailure();
+                repeater.AddChild(A.TaskStub().WithUpdateStatus(TaskStatus.Continue).Build());
+
+                Assert.AreEqual(TaskStatus.Continue, repeater.Update());
+            }
+
+            [Test]
+            public void Does_not_crash_if_no_child () {
+                var repeater = new RepeatUntilFailure();
+
+                Assert.DoesNotThrow(() => repeater.Update());
+            }
+        }
+    }
+}