From 918621db73a5a8d30fd79624ec61b36ac86aa50c Mon Sep 17 00:00:00 2001
From: Evan Hemsley <evan@moonside.games>
Date: Wed, 17 Jul 2019 11:46:54 -0700
Subject: [PATCH] adds SomeComponent to Engine and renames Some to SomeMessage

---
 encompass-cs/Engine.cs | 12 ++++++++-
 test/EngineTest.cs     | 60 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/encompass-cs/Engine.cs b/encompass-cs/Engine.cs
index 5090cde..ab44af6 100644
--- a/encompass-cs/Engine.cs
+++ b/encompass-cs/Engine.cs
@@ -205,7 +205,7 @@ namespace Encompass
             return messageManager.GetMessagesByType<TMessage>();
         }
 
-        protected bool Some<TMessage>() where TMessage : struct, IMessage
+        protected bool SomeMessage<TMessage>() where TMessage : struct, IMessage
         {
             if (!readTypes.Contains(typeof(TMessage)))
             {
@@ -215,6 +215,16 @@ namespace Encompass
             return messageManager.GetMessagesByType<TMessage>().Any();
         }
 
+        protected bool SomeComponent<TComponent>() where TComponent : struct, IComponent
+        {
+            if (!readTypes.Contains(typeof(TComponent)))
+            {
+                throw new IllegalReadException("Engine {0} tried to read undeclared Component {1}", this.GetType().Name, typeof(TComponent).Name);
+            }
+
+            return componentManager.GetActiveComponentsByType<TComponent>().Any();
+        }
+
         protected void Destroy(Guid entityID)
         {
             entityManager.MarkForDestroy(entityID);
diff --git a/test/EngineTest.cs b/test/EngineTest.cs
index 1ae33f6..95b6fe9 100644
--- a/test/EngineTest.cs
+++ b/test/EngineTest.cs
@@ -292,20 +292,20 @@ namespace Tests
         }
 
         [Reads(typeof(MockMessage))]
-        class SomeTestEngine : Engine
+        class SomeMessageTestEngine : Engine
         {
             public override void Update(double dt)
             {
-                someTest = this.Some<MockMessage>();
+                someTest = this.SomeMessage<MockMessage>();
             }
         }
 
         [Test]
-        public void Some()
+        public void SomeMessage()
         {
             var worldBuilder = new WorldBuilder();
             worldBuilder.AddEngine(new EmitMockMessageEngine());
-            worldBuilder.AddEngine(new SomeTestEngine());
+            worldBuilder.AddEngine(new SomeMessageTestEngine());
 
             var world = worldBuilder.Build();
 
@@ -314,26 +314,70 @@ namespace Tests
             Assert.That(someTest, Is.True);
         }
 
-        class UndeclaredSomeEngine : Engine
+        class UndeclaredSomeMessageEngine : Engine
         {
             public override void Update(double dt)
             {
-                someTest = this.Some<MockMessage>();
+                someTest = this.SomeMessage<MockMessage>();
             }
         }
 
         [Test]
-        public void IllegalSome()
+        public void UndeclaredSomeMessage()
         {
             var worldBuilder = new WorldBuilder();
             worldBuilder.AddEngine(new EmitMockMessageEngine());
-            worldBuilder.AddEngine(new UndeclaredSomeEngine());
+            worldBuilder.AddEngine(new UndeclaredSomeMessageEngine());
 
             var world = worldBuilder.Build();
 
             Assert.Throws<IllegalReadException>(() => world.Update(0.01f));
         }
 
+        [Reads(typeof(MockComponent))]
+        class SomeComponentTestEngine : Engine
+        {
+            public override void Update(double dt)
+            {
+                Assert.IsTrue(SomeComponent<MockComponent>());
+            }
+        }
+
+        [Test]
+        public void SomeComponent()
+        {
+            var worldBuilder = new WorldBuilder();
+
+            var entity = worldBuilder.CreateEntity();
+            worldBuilder.AddComponent(entity, new MockComponent());
+
+            var world = worldBuilder.Build();
+
+            world.Update(0.01);
+        }
+
+        class UndeclaredSomeComponentEngine : Engine
+        {
+            public override void Update(double dt)
+            {
+                SomeComponent<MockComponent>();
+            }
+        }
+
+        [Test]
+        public void UndeclaredSomeComponent()
+        {
+            var worldBuilder = new WorldBuilder();
+            worldBuilder.AddEngine(new UndeclaredSomeComponentEngine());
+
+            var entity = worldBuilder.CreateEntity();
+            worldBuilder.AddComponent(entity, new MockComponent());
+
+            var world = worldBuilder.Build();
+
+            Assert.Throws<IllegalReadException>(() => world.Update(0.01));
+        }
+
         static ValueTuple<Guid, MockComponent> pairA;
         static ValueTuple<Guid, MockComponent> pairB;