Unit testing parallel scheduled jobs?

I am trying to set up the most basic unit test possible. I have similar tests for existing code already for Unity3D OOP. All I want to do is run a job once and check and see if it works.

Game/Physics/GasHeatDiffusionSystem.cs

Code (csharp):

1. using System.Diagnostics;
2. using Unity.Collections;
3. using Unity.Entities;
4. using Unity.Jobs;
5.  
6. namespace Game.Physics
7. {
8.     /// <summary>
9.     /// System that evenly distributes heat between gas elements in an entity.
10.     /// </summary>
11.     public class GasHeatDiffusionSystem : SystemBase
12.     {
13.         EndSimulationEntityCommandBufferSystem m_EndSimulationEcbSystem;
14.         protected override void OnCreate() {
15.             base.OnCreate();
16.             m_EndSimulationEcbSystem = World.GetOrCreateSystem<EndSimulationEntityCommandBufferSystem>();
17.         }
18.  
19.         protected override void OnUpdate() {
20.             var entityCommandBuffer = m_EndSimulationEcbSystem.CreateCommandBuffer().AsParallelWriter();
21.  
22.             // find all jars that have been made inhomogenous by content changes
23.             Entities
24.                 .WithAll<GasHeatInhomogeneousTag>()
25.                 .ForEach((Entity entity, int entityInQueryIndex, DynamicBuffer<ChemicalComposition> contents) => {
26.                     // Removed code for sake of testing.
27.                     // Heat is now homogenous, queue entity to remove tag.
28.                     entityCommandBuffer.RemoveComponent<GasHeatInhomogeneousTag>(entityInQueryIndex, entity);
29.                 })
30.                 .ScheduleParallel();
31.  
32.             m_EndSimulationEcbSystem.AddJobHandleForProducer(this.Dependency);
33.         }
34.     }
35. }

Tests/ChemicalTestScript.cs

Code (csharp):

1. using NUnit.Framework;
2. using Unity.Entities.Tests;
3. using Game.Physics;
4. using Unity.Entities;
5.  
6. namespace Tests
7. {
8.     [TestFixture]
9.     public class ChemicalTestScript : ECSTestsFixture
10.     {
11.         const float MolesInLiterOfWater = 55.5084343f;
12.  
13.         #region Chemical References
14.         Chemical Nitrogen() {
15.             return new Chemical {
16.                 MeltingPoint = 63.15f,
17.                 BoilingPoint = 77.355f,
18.                 MolarMass = 28.014f,
19.                 RelativeDensity = 0.804f,
20.                 HeatCapacity = 29.124f,
21.                 ThermalConductivity = 0.02583f
22.             };
23.         }
24.  
25.         Chemical Oxygen() {
26.             return new Chemical {
27.                 MeltingPoint = 54.36f,
28.                 BoilingPoint = 90.188f,
29.                 MolarMass = 31.988f,
30.                 RelativeDensity = 1.14f,
31.                 HeatCapacity = 29.378f,
32.                 ThermalConductivity = 0.02658f
33.             };
34.         }
35.  
36.         Chemical Water() {
37.             return new Chemical {
38.                 MeltingPoint = 273.15f,
39.                 BoilingPoint = 373.13f,
40.                 MolarMass = 18.01528f,
41.                 RelativeDensity = 1f,
42.                 HeatCapacity = 75.385f,
43.                 ThermalConductivity = 0.6065f
44.             };
45.         }
46.         #endregion
47.  
48.         [Test]
49.         public void GasHeatDiffusionSystemDiffusionPasses() {
50.             var entity = m_Manager.CreateEntity(
51.                 typeof(GasHeatInhomogeneousTag),
52.                 typeof(ChemicalComposition)
53.             );
54.  
55.             var buffer = m_Manager.GetBuffer<ChemicalComposition>(entity);
56.             buffer.Add(new ChemicalComposition {
57.                 Chemical = Nitrogen(),
58.                 Matter = 79f,
59.                 Temp = Temp.Boiling
60.             });
61.             buffer.Add(new ChemicalComposition {
62.                 Chemical = Oxygen(),
63.                 Matter = 21f,
64.                 Temp = Temp.Room
65.             });
66.  
67.             m_Manager.World.CreateSystem<GasHeatDiffusionSystem>();
68.             m_Manager.World.Update();
69.  
70.             Assert.IsFalse(m_Manager.HasComponent<GasHeatInhomogeneousTag>(entity));
71.             Assert.AreEqual(buffer[0].Temp, buffer[1].Temp);
72.         }
73.     }
74. }

This fails right at the first hurdle. The `GasHeatInhomogenousTag` is not removed from the entity. I have tried many different system types and ways of calling the update, none work.

m_Manager.World.CreateSystem<GasHeatDiffusionSystem>().Update;
World.CreateSystem<GasHeatDiffusionSystem>().Update();
World.Update();

etc. nothing works. I cannot make a system run, conclude it, and see the results. Why? This was so easy to do before.