Add test for failing and then successfully starting a round (#27375)

* Add test for failing and then successfully starting nukeops preset

* Make test independent from nukeops

* Fix nullable error

Content.IntegrationTests/Tests/GameRules/FailAndStartPresetTest.cs

@@ -0,0 +1,152 @@
+#nullable enable
+using Content.Server.GameTicking;
+using Content.Server.GameTicking.Components;
+using Content.Server.GameTicking.Presets;
+using Content.Shared.CCVar;
+using Content.Shared.GameTicking;
+using Robust.Shared.GameObjects;
+
+namespace Content.IntegrationTests.Tests.GameRules;
+
+[TestFixture]
+public sealed class FailAndStartPresetTest
+{
+    [TestPrototypes]
+    private const string Prototypes = @"
+- type: gamePreset
+  id: TestPreset
+  alias:
+    - nukeops
+  name: Test Preset
+  description: """"
+  showInVote: false
+  rules:
+  - TestRule
+
+- type: gamePreset
+  id: TestPresetTenPlayers
+  alias:
+    - nukeops
+  name: Test Preset 10 players
+  description: """"
+  showInVote: false
+  rules:
+  - TestRuleTenPlayers
+
+- type: entity
+  id: TestRule
+  parent: BaseGameRule
+  noSpawn: true
+  components:
+  - type: GameRule
+    minPlayers: 0
+  - type: TestRule
+
+- type: entity
+  id: TestRuleTenPlayers
+  parent: BaseGameRule
+  noSpawn: true
+  components:
+  - type: GameRule
+    minPlayers: 10
+  - type: TestRule
+";
+
+    /// <summary>
+    ///     Test that a nuke ops gamemode can start after failing to start once.
+    /// </summary>
+    [Test]
+    public async Task FailAndStartTest()
+    {
+        await using var pair = await PoolManager.GetServerClient(new PoolSettings
+        {
+            Dirty = true,
+            DummyTicker = false,
+            Connected = true,
+            InLobby = true
+        });
+
+        var server = pair.Server;
+        var client = pair.Client;
+        var entMan = server.EntMan;
+        var ticker = server.System<GameTicker>();
+        server.System<TestRuleSystem>().Run = true;
+
+        Assert.That(server.CfgMan.GetCVar(CCVars.GridFill), Is.False);
+        Assert.That(server.CfgMan.GetCVar(CCVars.GameLobbyFallbackEnabled), Is.True);
+        Assert.That(server.CfgMan.GetCVar(CCVars.GameLobbyDefaultPreset), Is.EqualTo("secret"));
+        server.CfgMan.SetCVar(CCVars.GridFill, true);
+        server.CfgMan.SetCVar(CCVars.GameLobbyFallbackEnabled, false);
+        server.CfgMan.SetCVar(CCVars.GameLobbyDefaultPreset, "TestPreset");
+
+        // Initially in the lobby
+        Assert.That(ticker.RunLevel, Is.EqualTo(GameRunLevel.PreRoundLobby));
+        Assert.That(client.AttachedEntity, Is.Null);
+        Assert.That(ticker.PlayerGameStatuses[client.User!.Value], Is.EqualTo(PlayerGameStatus.NotReadyToPlay));
+
+        // Try to start nukeops without readying up
+        await pair.WaitCommand("setgamepreset TestPresetTenPlayers");
+        await pair.WaitCommand("startround");
+        await pair.RunTicksSync(10);
+
+        // Game should not have started
+        Assert.That(ticker.RunLevel, Is.EqualTo(GameRunLevel.PreRoundLobby));
+        Assert.That(ticker.PlayerGameStatuses[client.User!.Value], Is.EqualTo(PlayerGameStatus.NotReadyToPlay));
+        Assert.That(!client.EntMan.EntityExists(client.AttachedEntity));
+        var player = pair.Player!.AttachedEntity;
+        Assert.That(!entMan.EntityExists(player));
+
+        // Ready up and start nukeops
+        await pair.WaitClientCommand("toggleready True");
+        Assert.That(ticker.PlayerGameStatuses[client.User!.Value], Is.EqualTo(PlayerGameStatus.ReadyToPlay));
+        await pair.WaitCommand("setgamepreset TestPreset");
+        await pair.WaitCommand("startround");
+        await pair.RunTicksSync(10);
+
+        // Game should have started
+        Assert.That(ticker.RunLevel, Is.EqualTo(GameRunLevel.InRound));
+        Assert.That(ticker.PlayerGameStatuses[client.User!.Value], Is.EqualTo(PlayerGameStatus.JoinedGame));
+        Assert.That(client.EntMan.EntityExists(client.AttachedEntity));
+        player = pair.Player!.AttachedEntity!.Value;
+        Assert.That(entMan.EntityExists(player));
+
+        ticker.SetGamePreset((GamePresetPrototype?)null);
+        server.CfgMan.SetCVar(CCVars.GridFill, false);
+        server.CfgMan.SetCVar(CCVars.GameLobbyFallbackEnabled, true);
+        server.CfgMan.SetCVar(CCVars.GameLobbyDefaultPreset, "secret");
+        server.System<TestRuleSystem>().Run = false;
+        await pair.CleanReturnAsync();
+    }
+}
+
+public sealed class TestRuleSystem : EntitySystem
+{
+    public bool Run;
+
+    public override void Initialize()
+    {
+        SubscribeLocalEvent<RoundStartAttemptEvent>(OnRoundStartAttempt);
+    }
+
+    private void OnRoundStartAttempt(RoundStartAttemptEvent args)
+    {
+        if (!Run)
+            return;
+
+        if (args.Forced || args.Cancelled)
+            return;
+
+        var query = EntityQueryEnumerator<TestRuleComponent, GameRuleComponent>();
+        while (query.MoveNext(out _, out _, out var gameRule))
+        {
+            var minPlayers = gameRule.MinPlayers;
+            if (args.Players.Length >= minPlayers)
+                continue;
+
+            args.Cancel();
+        }
+    }
+}
+
+[RegisterComponent]
+public sealed partial class TestRuleComponent : Component;