Fixes secret only adding game rules, not starting them (#11005)

Content.IntegrationTests/Tests/GameRules/SecretStartsTest.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Content.Server.GameTicking;
+using Content.Server.GameTicking.Rules;
+using NUnit.Framework;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Prototypes;
+
+namespace Content.IntegrationTests.Tests.GameRules;
+
+[TestFixture]
+public sealed class SecretStartsTest
+{
+    /// <summary>
+    ///     Tests that when secret is started, all of the game rules it successfully adds are also started.
+    /// </summary>
+    [Test]
+    public async Task TestSecretStarts()
+    {
+        await using var pairTracker = await PoolManager.GetServerClient(new PoolSettings()
+        {
+            NoClient = true,
+            Dirty = true,
+        });
+
+        var server = pairTracker.Pair.Server;
+        await server.WaitIdleAsync();
+        var protoMan = server.ResolveDependency<IPrototypeManager>();
+        var gameTicker = server.ResolveDependency<IEntitySystemManager>().GetEntitySystem<GameTicker>();
+
+        await server.WaitAssertion(() =>
+        {
+            gameTicker.StartGameRule(protoMan.Index<GameRulePrototype>("Secret"));
+        });
+
+        // Wait three ticks for any random update loops that might happen
+        await server.WaitRunTicks(3);
+
+        await server.WaitAssertion(() =>
+        {
+            foreach (var rule in gameTicker.AddedGameRules)
+            {
+                Assert.That(gameTicker.StartedGameRules.Contains(rule));
+            }
+
+            // End all rules
+            gameTicker.ClearGameRules();
+        });
+
+        await pairTracker.CleanReturnAsync();
+    }
+}