More tests:

-fixed bug in EntityManger.addComponents
-added many new tests

tests/basic.d

@@ -101,7 +101,7 @@ struct EmptySystem
 
 void beforeEveryTest()
 {
-    gEM.initialize(1);
+    gEM.initialize(0);
 
     gEM.beginRegister();
 
@@ -493,11 +493,10 @@ unittest
     gEM.end();
 }
 
-
-
 @("SystemEntityCallbacks")
 unittest
 {
+    //TODO: this test is WIP by now 
     struct TestSystem
     {
         mixin ECS.System!16;
@@ -569,4 +568,288 @@ unittest
     assert(system.add == 2);
 
     gEM.commit();
+}
+
+@("TemplateCoverage")
+unittest
+{
+    struct TestSystem 
+    {
+        mixin ECS.System;
+
+        struct EntitiesData
+        {
+            int length;
+            Entity[] entity;
+            @readonly CLong[] long_;
+            @optional CInt[] int_;
+            @readonly CFloat[] float_;
+        }
+
+        mixin ECS.ExcludedComponents!(CUnregistered);
+    
+        void onUpdate(EntitiesData data)
+        {
+
+        }
+    }
+
+    gEM.beginRegister();
+
+    gEM.registerComponent!CUnregistered;
+
+    gEM.registerSystem!TestSystem(0);
+
+    gEM.endRegister();
+}
+
+@("UnregisteredSystem")
+unittest
+{
+    struct TestSystem 
+    {
+        mixin ECS.System;
+
+        struct EntitiesData
+        {
+            int length;
+            Entity[] entity;
+            @readonly CLong[] long_;
+            @optional CInt[] int_;
+            @readonly CFloat[] float_;
+        }
+    
+        void onUpdate(EntitiesData data)
+        {
+
+        }
+    }
+
+    assert(gEM.getSystem!TestSystem is null);
+    assert(gEM.getSystem(TestSystem.system_id) is null);
+}
+
+@("MultithreadedUpdate")
+unittest
+{
+    struct TestSystem 
+    {
+        mixin ECS.System;
+
+        struct EntitiesData
+        {
+            int length;
+            Entity[] entity;
+            @readonly CLong[] long_;
+            @optional CInt[] int_;
+            @readonly CFloat[] float_;
+        }
+    
+        void onUpdate(EntitiesData data)
+        {
+            update++;
+            entities += data.length;
+        }
+
+        int update = 0;
+        int entities = 0;
+    }
+
+    struct TestEmptySystem 
+    {
+        mixin ECS.System;
+
+        struct EntitiesData
+        {
+            int length;
+        }
+    
+        void onUpdate(EntitiesData data)
+        {
+            update++;
+        }
+
+        int update = 0;
+    }
+
+    void dispatch(EntityManager.JobGroup grp)
+    {
+        foreach(job; grp.jobs)
+        {
+            job.execute();
+        }
+    }
+
+    uint getID()
+    {
+        return 0;
+    }
+
+    gEM.setMultithreadingCallbacks(&dispatch, &getID);
+
+    gEM.beginRegister();
+
+    gEM.registerPass("custom");
+    gEM.registerSystem!TestSystem(-1,"custom");
+    gEM.registerSystem!TestEmptySystem(1,"custom");
+
+    gEM.endRegister();
+
+    TestSystem* system = gEM.getSystem!TestSystem;
+    TestEmptySystem* empty_system = gEM.getSystem!TestEmptySystem;
+
+    gEM.begin();
+
+    gEM.updateMT("custom");
+    
+    gEM.end();
+
+    assert(system.update == 0);
+    assert(system.entities == 0);
+    assert(empty_system.update == 1);
+
+    ushort[2] ids = [CLong.component_id,CFloat.component_id];
+    EntityTemplate* tmpl = gEM.allocateTemplate(ids);
+    scope (exit) gEM.freeTemplate(tmpl);
+    gEM.addEntity(tmpl);
+
+    gEM.begin();
+
+    gEM.updateMT("custom");
+    
+    gEM.end();
+
+    assert(system.update == 1);
+    assert(system.entities == 1);
+    assert(empty_system.update == 2);
+    system.entities = 0;
+
+    foreach(i;0..2000)gEM.addEntity(tmpl);
+
+    gEM.begin();
+
+    gEM.updateMT("custom");
+    
+    gEM.end();
+
+    assert(system.update > 2);
+    assert(system.entities == 2001);
+    assert(empty_system.update == 3);
+    system.entities = 0;
+
+    foreach(i;0..10000)gEM.addEntity(tmpl);
+
+    gEM.begin();
+
+    gEM.updateMT("custom");
+    
+    gEM.end();
+
+    assert(system.entities == 12001);
+}
+
+unittest
+{
+    assert(gEM.pageSize == 32768);
+    assert(gEM.pagesInBlock == 128);
+}
+
+@("AddRemoveEntities")
+unittest
+{
+    ushort[3] ids = [CLong.component_id,CFloat.component_id,CShort.component_id];
+    EntityTemplate* tmpl = gEM.allocateTemplate(ids);
+    scope (exit) gEM.freeTemplate(tmpl);
+
+    EntityID[5000] entities;
+
+    foreach(i;0..4)
+    {
+        foreach(j;0..5000)
+        {
+            entities[j] = gEM.addEntity(tmpl).id;
+        }
+        gEM.commit();
+        foreach(j;0..5000)
+        {
+            gEM.removeEntity(entities[j]);
+        }
+        gEM.commit();
+    }
+}
+
+@("ChangeEntityComponents")
+unittest
+{
+    gEM.beginRegister();
+
+    gEM.registerComponent!CUnregistered;
+
+    gEM.endRegister();
+
+    ushort[1] ids = [CLong.component_id];
+    EntityTemplate* tmpl = gEM.allocateTemplate(ids);
+    scope (exit) gEM.freeTemplate(tmpl);
+
+    EntityID id = gEM.addEntity(tmpl).id;
+    gEM.commit();
+    Entity* entity = gEM.getEntity(id);
+    assert(entity.id == id);
+    assert(entity.getComponent!CLong !is null);
+    assert(entity.getComponent!CFloat is null);
+    assert(entity.getComponent!CUnregistered is null);
+    assert(entity.getComponent!CShort is null);
+    assert(entity.getComponent!CInt is null);
+    assert(*entity.getComponent!CLong == 10);
+
+    gEM.addComponents(id, CShort(15), CFloat(13));
+    gEM.commit();
+
+    entity = gEM.getEntity(id);
+    assert(entity.id == id);
+    assert(entity.getComponent!CLong !is null);
+    assert(entity.getComponent!CFloat !is null);
+    assert(entity.getComponent!CUnregistered is null);
+    assert(entity.getComponent!CShort !is null);
+    assert(entity.getComponent!CInt is null);
+    assert(*entity.getComponent!CLong == 10);
+    assert(*entity.getComponent!CShort == 15);
+    assert(*entity.getComponent!CFloat == 13);
+
+    ushort[3] ids2 = [CFloat.component_id, CLong.component_id, CUnregistered.component_id];
+    gEM.removeComponents(id, ids2);
+    gEM.commit();
+
+    entity = gEM.getEntity(id);
+    assert(entity.id == id);
+    assert(entity.getComponent!CLong is null);
+    assert(entity.getComponent!CFloat is null);
+    assert(entity.getComponent!CUnregistered is null);
+    assert(entity.getComponent!CShort !is null);
+    assert(entity.getComponent!CInt is null);
+    assert(*entity.getComponent!CShort == 15);
+
+    gEM.removeComponents(id, ids2);
+    gEM.addComponents(id, CShort(11), CLong(2)); //wrong order of components 
+    gEM.commit();
+
+    entity = gEM.getEntity(id);
+    assert(entity.id == id);
+    assert(entity.getComponent!CLong !is null);
+    assert(entity.getComponent!CFloat is null);
+    assert(entity.getComponent!CUnregistered is null);
+    assert(entity.getComponent!CShort !is null);
+    assert(entity.getComponent!CInt is null);
+    assert(*entity.getComponent!CLong == 2);
+    assert(*entity.getComponent!CShort == 15);
+
+    gEM.removeEntity(id);
+
+    entity = gEM.getEntity(id);
+    assert(entity !is null);
+    assert(entity.id == id);
+
+    gEM.commit();
+    entity = gEM.getEntity(id);
+    assert(entity is null);
 }