Add test for try disease adding (#10563)

Content.IntegrationTests/Tests/Disease/TryAddDisease.cs

@@ -0,0 +1,35 @@
+using System.Threading.Tasks;
+using Content.Server.Disease;
+using Content.Shared.Disease;
+using NUnit.Framework;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Prototypes;
+
+namespace Content.IntegrationTests.Tests.Disease;
+
+[TestFixture]
+[TestOf(typeof(DiseaseSystem))]
+public sealed class DeviceNetworkTest
+{
+    [Test]
+    public async Task AddAllDiseases()
+    {
+        await using var pairTracker = await PoolManager.GetServerClient(new PoolSettings{NoClient = true});
+        var server = pairTracker.Pair.Server;
+        var testMap = await PoolManager.CreateTestMap(pairTracker);
+        await server.WaitPost(() =>
+        {
+            var protoManager = IoCManager.Resolve<IPrototypeManager>();
+            var entManager = IoCManager.Resolve<IEntityManager>();
+            var entSysManager = IoCManager.Resolve<IEntitySystemManager>();
+            var diseaseSystem = entSysManager.GetEntitySystem<DiseaseSystem>();
+
+            var sickEntity = entManager.SpawnEntity("MobHuman", testMap.GridCoords);
+            foreach (var diseaseProto in protoManager.EnumeratePrototypes<DiseasePrototype>())
+            {
+                diseaseSystem.TryAddDisease(sickEntity, diseaseProto);
+            }
+        });
+    }
+}