Add basic movement phase update tests

MultiversalDiplomacy/Model/Season.cs

@@ -39,6 +39,11 @@ public class Season
     /// </summary>
     public int Timeline { get; }
 
+    /// <summary>
+    /// The season's spatial location as a turn-timeline tuple.
+    /// </summary>
+    public (int Turn, int Timeline) Coord => (this.Turn, this.Timeline);
+
     /// <summary>
     /// The shared timeline number generator.
     /// </summary>

MultiversalDiplomacy/Model/World.cs

@@ -232,6 +232,19 @@ public class World
             ? GetLocation(provinceName, l => l.Type == LocationType.Water)
             : GetLocation(provinceName, l => l.Name == coastName || l.Abbreviation == coastName);
 
+    /// <summary>
+    /// Get a season by coordinate. Throws if the season is not found.
+    /// </summary>
+    public Season GetSeason(int turn, int timeline)
+    {
+        Season? foundSeason = this.Seasons.SingleOrDefault(
+            s => s != null && s.Turn == turn && s.Timeline == timeline,
+            null);
+        if (foundSeason == null) throw new KeyNotFoundException(
+            $"Season {turn}:{timeline} not found");
+        return foundSeason;
+    }
+
     /// <summary>
     /// Get a power by name. Throws if there is not exactly one such power.
     /// </summary>
@@ -248,14 +261,18 @@ public class World
     }
 
     /// <summary>
-    /// Returns a unit in a province. Throws if there is not exactly one such unit.
+    /// Returns a unit in a province. Throws if there are duplicate units.
     /// </summary>
-    public Unit? GetUnitAt(string provinceName)
+    public Unit GetUnitAt(string provinceName, (int turn, int timeline)? seasonCoord = null)
     {
         Province province = GetProvince(provinceName);
+        seasonCoord ??= (this.RootSeason.Turn, this.RootSeason.Timeline);
+        Season season = GetSeason(seasonCoord.Value.turn, seasonCoord.Value.timeline);
         Unit? foundUnit = this.Units.SingleOrDefault(
-            u => u != null && u.Location.Province == province,
+            u => u != null && u.Location.Province == province && u.Season == season,
             null);
+        if (foundUnit == null) throw new KeyNotFoundException(
+            $"Unit at {province} at {season} not found");
         return foundUnit;
     }
 

MultiversalDiplomacyTests/MovementAdjudicatorTest.cs

@@ -152,4 +152,135 @@ public class MovementAdjudicatorTest
         Assert.That(attackMun.MinValue, Is.EqualTo(2));
         Assert.That(attackMun.MaxValue, Is.EqualTo(2));
     }
+
+    [Test]
+    public void Update_SingleHold()
+    {
+        TestCaseBuilder setup = new(World.WithStandardMap());
+        setup["Germany"]
+            .Army("Mun").Holds().GetReference(out var mun);
+
+        setup.ValidateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun, Is.Valid);
+
+        setup.AdjudicateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun, Is.NotDislodged);
+
+        World updated = setup.UpdateWorld(MovementPhaseAdjudicator.Instance);
+
+        // Confirm the future was created
+        Assert.That(updated.Seasons.Count, Is.EqualTo(2));
+        Season future = updated.Seasons.Single(s => s != updated.RootSeason);
+        Assert.That(future.Past, Is.EqualTo(updated.RootSeason));
+        Assert.That(future.Futures, Is.Empty);
+        Assert.That(future.Timeline, Is.EqualTo(updated.RootSeason.Timeline));
+        Assert.That(future.Turn, Is.EqualTo(Season.FIRST_TURN + 1));
+
+        // Confirm the unit was created
+        Assert.That(updated.Units.Count, Is.EqualTo(2));
+        Unit second = updated.Units.Single(u => u.Past != null);
+        Assert.That(second.Location, Is.EqualTo(mun.Order.Unit.Location));
+    }
+
+    [Test]
+    public void Update_DoubleHold()
+    {
+        TestCaseBuilder setup = new(World.WithStandardMap());
+        setup[(0, 0)]
+            .GetReference(out Season s1)
+            ["Germany"]
+                .Army("Mun").Holds().GetReference(out var mun1);
+
+        Assert.That(mun1.Order.Unit.Season, Is.EqualTo(s1));
+        setup.ValidateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun1, Is.Valid);
+        setup.AdjudicateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun1, Is.NotDislodged);
+        World updated = setup.UpdateWorld(MovementPhaseAdjudicator.Instance);
+
+        // Confirm the future was created
+        Season s2 = updated.GetSeason(1, 0);
+        Assert.That(s2.Past, Is.EqualTo(s1));
+        Assert.That(s2.Futures, Is.Empty);
+        Assert.That(s2.Timeline, Is.EqualTo(s1.Timeline));
+        Assert.That(s2.Turn, Is.EqualTo(s1.Turn + 1));
+
+        // Confirm the unit was created in the future
+        Unit u2 = updated.GetUnitAt("Mun", s2.Coord);
+        Assert.That(updated.Units.Count, Is.EqualTo(2));
+        Assert.That(u2, Is.Not.EqualTo(mun1.Order.Unit));
+        Assert.That(u2.Past, Is.EqualTo(mun1.Order.Unit));
+        Assert.That(u2.Season, Is.EqualTo(s2));
+
+        setup = new(updated);
+        setup[(1, 0)]
+            ["Germany"]
+                .Army("Mun").Holds().GetReference(out var mun2);
+
+        // Validate the second set of orders
+        var validations = setup.ValidateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(validations.Count, Is.EqualTo(1));
+        Assert.That(mun2, Is.Valid);
+
+        // Adjudicate the second set of orders
+        var adjudications = setup.AdjudicateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun2, Is.NotDislodged);
+
+        // Update the world again
+        updated = setup.UpdateWorld(MovementPhaseAdjudicator.Instance);
+        Season s3 = updated.GetSeason(s2.Turn + 1, s2.Timeline);
+        Unit u3 = updated.GetUnitAt("Mun", s3.Coord);
+        Assert.That(u3.Past, Is.EqualTo(mun2.Order.Unit));
+    }
+
+    [Test]
+    public void Update_DoubleMove()
+    {
+        TestCaseBuilder setup = new(World.WithStandardMap());
+        setup[(0, 0)]
+            .GetReference(out Season s1)
+            ["Germany"]
+                .Army("Mun").MovesTo("Tyr").GetReference(out var mun1);
+
+        Assert.That(mun1.Order.Unit.Season, Is.EqualTo(s1));
+        setup.ValidateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun1, Is.Valid);
+        setup.AdjudicateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(mun1, Is.Victorious);
+        World updated = setup.UpdateWorld(MovementPhaseAdjudicator.Instance);
+
+        // Confirm the future was created
+        Season s2 = updated.GetSeason(s1.Turn + 1, s1.Timeline);
+        Assert.That(s2.Past, Is.EqualTo(s1));
+        Assert.That(s2.Futures, Is.Empty);
+        Assert.That(s2.Timeline, Is.EqualTo(s1.Timeline));
+        Assert.That(s2.Turn, Is.EqualTo(s1.Turn + 1));
+
+        // Confirm the unit was created in the future
+        Unit u2 = updated.GetUnitAt("Tyr", s2.Coord);
+        Assert.That(updated.Units.Count, Is.EqualTo(2));
+        Assert.That(u2, Is.Not.EqualTo(mun1.Order.Unit));
+        Assert.That(u2.Past, Is.EqualTo(mun1.Order.Unit));
+        Assert.That(u2.Season, Is.EqualTo(s2));
+
+        setup = new(updated);
+        setup[(1, 0)]
+            ["Germany"]
+                .Army("Tyr").MovesTo("Mun").GetReference(out var tyr2);
+
+        // Validate the second set of orders
+        var validations = setup.ValidateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(validations.Count, Is.EqualTo(1));
+        Assert.That(tyr2, Is.Valid);
+
+        // Adjudicate the second set of orders
+        var adjudications = setup.AdjudicateOrders(MovementPhaseAdjudicator.Instance);
+        Assert.That(tyr2, Is.Victorious);
+
+        // Update the world again
+        updated = setup.UpdateWorld(MovementPhaseAdjudicator.Instance);
+        Season s3 = updated.GetSeason(s2.Turn + 1, s2.Timeline);
+        Unit u3 = updated.GetUnitAt("Mun", s3.Coord);
+        Assert.That(u3.Past, Is.EqualTo(u2));
+    }
 }

MultiversalDiplomacyTests/SeasonTests.cs

@@ -47,4 +47,19 @@ public class SeasonTests
         Assert.That(b2.InAdjacentTimeline(c1), Is.True, "Expected alts with common origin to be adjacent");
         Assert.That(b2.InAdjacentTimeline(d1), Is.False, "Expected alts from different origins not to be adjacent");
     }
+
+    [Test]
+    public void LookupTest()
+    {
+        World world = World.WithStandardMap();
+        Season s2 = world.RootSeason.MakeNext();
+        Season s3 = s2.MakeNext();
+        Season s4 = s2.MakeFork();
+        World updated = world.Update(seasons: world.Seasons.Append(s2).Append(s3).Append(s4));
+
+        Assert.That(updated.GetSeason(Season.FIRST_TURN, 0), Is.EqualTo(updated.RootSeason));
+        Assert.That(updated.GetSeason(Season.FIRST_TURN + 1, 0), Is.EqualTo(s2));
+        Assert.That(updated.GetSeason(Season.FIRST_TURN + 2, 0), Is.EqualTo(s3));
+        Assert.That(updated.GetSeason(Season.FIRST_TURN + 2, 1), Is.EqualTo(s4));
+    }
 }

MultiversalDiplomacyTests/TestCaseBuilder.cs

@@ -11,11 +11,37 @@ namespace MultiversalDiplomacyTests;
 /// </summary>
 public class TestCaseBuilder
 {
+    /// <summary>
+    /// Context for choosing a season to define orders for.
+    /// </summary>
+    public interface ISeasonContext
+    {
+        /// <summary>
+        /// Choose a new season to define orders for.
+        /// </summary>
+        public ISeasonContext this[(int turn, int timeline) seasonCoord] { get; }
+
+        /// <summary>
+        /// Get the context for defining the orders for a power.
+        /// </summary>
+        public IPowerContext this[string powerName] { get; }
+
+        /// <summary>
+        /// Save a reference to this season.
+        /// </summary>
+        public ISeasonContext GetReference(out Season season);
+    }
+
     /// <summary>
     /// Context for defining orders given by a power.
     /// </summary>
     public interface IPowerContext
     {
+        /// <summary>
+        /// Choose a new season to define orders for.
+        /// </summary>
+        public ISeasonContext this[(int turn, int timeline) seasonCoord] { get; }
+
         /// <summary>
         /// Get the context for defining the orders for another power.
         /// </summary>
@@ -135,6 +161,11 @@ public class TestCaseBuilder
     /// </summary>
     public interface IOrderDefinedContext<OrderType> where OrderType : Order
     {
+        /// <summary>
+        /// Choose a new season to define orders for.
+        /// </summary>
+        public ISeasonContext this[(int turn, int timeline) seasonCoord] { get; }
+
         /// <summary>
         /// Get the context for defining the orders for another power.
         /// </summary>
@@ -159,34 +190,31 @@ public class TestCaseBuilder
     public World World { get; private set; }
     public ReadOnlyCollection<Order> Orders { get; }
     private List<Order> OrderList;
-    private Season Season;
     public List<OrderValidation>? ValidationResults { get; private set; }
     public List<AdjudicationDecision>? AdjudicationResults { get; private set; }
 
     /// <summary>
     /// Create a test case builder that will operate on a world.
     /// </summary>
-    public TestCaseBuilder(World world, Season? season = null)
+    public TestCaseBuilder(World world)
     {
         this.World = world;
         this.OrderList = new();
         this.Orders = new(this.OrderList);
-        this.Season = season ?? this.World.Seasons.First();
         this.ValidationResults = null;
         this.AdjudicationResults = null;
     }
 
     /// <summary>
-    /// Get the context for defining the orders for a power.
+    /// Get the context for defining the orders for a power. Defaults to the root season.
     /// </summary>
-    public IPowerContext this[string powerName]
+    public IPowerContext this[string powerName] => this[(0, 0)][powerName];
-    {
+
-        get
+    /// <summary>
-        {
+    /// Get the context for defining the orders for a season.
-            Power power = this.World.GetPower(powerName);
+    /// </summary>
-            return new PowerContext(this, power);
+    public ISeasonContext this[(int turn, int timeline) seasonCoord]
-        }
+        => new SeasonContext(this, this.World.GetSeason(seasonCoord.turn, seasonCoord.timeline));
-    }
 
     /// <summary>
     /// Get a unit matching a description. If no such unit exists, one is created and added to the
@@ -253,19 +281,48 @@ public class TestCaseBuilder
         return this.World;
     }
 
+    private class SeasonContext : ISeasonContext
+    {
+        public TestCaseBuilder Builder;
+        public Season Season;
+
+        public SeasonContext(TestCaseBuilder Builder, Season season)
+        {
+            this.Builder = Builder;
+            this.Season = season;
+        }
+
+        public ISeasonContext this[(int turn, int timeline) seasonCoord]
+            => this.Builder[(seasonCoord.turn, seasonCoord.timeline)];
+
+        public IPowerContext this[string powerName]
+            => new PowerContext(this, this.Builder.World.GetPower(powerName));
+
+        public ISeasonContext GetReference(out Season season)
+        {
+            season = this.Season;
+            return this;
+        }
+    }
+
     private class PowerContext : IPowerContext
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public Power Power;
 
-        public PowerContext(TestCaseBuilder Builder, Power Power)
+        public PowerContext(SeasonContext seasonContext, Power Power)
         {
-            this.Builder = Builder;
+            this.Builder = seasonContext.Builder;
+            this.SeasonContext = seasonContext;
             this.Power = Power;
         }
 
+        public ISeasonContext this[(int turn, int timeline) seasonCoord]
+            => this.SeasonContext[seasonCoord];
+
         public IPowerContext this[string powerName]
-            => this.Builder[powerName];
+            => this.SeasonContext[powerName];
 
         public IUnitContext Army(string provinceName, string? powerName = null)
         {
@@ -274,7 +331,7 @@ public class TestCaseBuilder
                 : this.Builder.World.GetPower(powerName);
             Location location = this.Builder.World.GetLand(provinceName);
             Unit unit = this.Builder.GetOrBuildUnit(
-                power, location, this.Builder.Season, UnitType.Army);
+                power, location, this.SeasonContext.Season, UnitType.Army);
             return new UnitContext(this, unit);
         }
 
@@ -285,7 +342,7 @@ public class TestCaseBuilder
                 : this.Builder.World.GetPower(powerName);
             Location location = this.Builder.World.GetWater(provinceName, coast);
             Unit unit = this.Builder.GetOrBuildUnit(
-                power, location, this.Builder.Season, UnitType.Fleet);
+                power, location, this.SeasonContext.Season, UnitType.Fleet);
             return new UnitContext(this, unit);
         }
     }
@@ -293,25 +350,21 @@ public class TestCaseBuilder
     private class UnitContext : IUnitContext
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public PowerContext PowerContext;
         public Unit Unit;
 
         public UnitContext(PowerContext powerContext, Unit unit)
         {
             this.Builder = powerContext.Builder;
+            this.SeasonContext = powerContext.SeasonContext;
             this.PowerContext = powerContext;
             this.Unit = unit;
         }
 
-        /// <summary>
-        /// Declare that a unit exists without giving it an order.
-        /// </summary>
         public IPowerContext Exists()
             => this.PowerContext;
 
-        /// <summary>
-        /// Order a unit to hold.
-        /// </summary>
         public IOrderDefinedContext<HoldOrder> Holds()
         {
             HoldOrder order = new HoldOrder(this.PowerContext.Power, this.Unit);
@@ -319,9 +372,6 @@ public class TestCaseBuilder
             return new OrderDefinedContext<HoldOrder>(this, order);
         }
 
-        /// <summary>
-        /// Order a unit to move to a destination.
-        /// </summary>
         public IOrderDefinedContext<MoveOrder> MovesTo(string provinceName, string? coast = null)
         {
             Location destination = this.Unit.Type == UnitType.Army
@@ -330,7 +380,7 @@ public class TestCaseBuilder
             MoveOrder moveOrder = new MoveOrder(
                 this.PowerContext.Power,
                 this.Unit,
-                this.Builder.Season,
+                this.SeasonContext.Season,
                 destination);
             this.Builder.OrderList.Add(moveOrder);
             return new OrderDefinedContext<MoveOrder>(this, moveOrder);
@@ -346,12 +396,14 @@ public class TestCaseBuilder
     private class ConvoyContext : IConvoyContext
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public PowerContext PowerContext;
         public UnitContext UnitContext;
 
         public ConvoyContext(UnitContext unitContext)
         {
             this.Builder = unitContext.Builder;
+            this.SeasonContext = unitContext.SeasonContext;
             this.PowerContext = unitContext.PowerContext;
             this.UnitContext = unitContext;
         }
@@ -363,7 +415,7 @@ public class TestCaseBuilder
                 : this.Builder.World.GetPower(powerName);
             Location location = this.Builder.World.GetLand(provinceName);
             Unit unit = this.Builder.GetOrBuildUnit(
-                power, location, this.Builder.Season, UnitType.Army);
+                power, location, this.SeasonContext.Season, UnitType.Army);
             return new ConvoyDestinationContext(this, unit);
         }
 
@@ -377,7 +429,7 @@ public class TestCaseBuilder
                 : this.Builder.World.GetPower(powerName);
             Location location = this.Builder.World.GetWater(provinceName, coast);
             Unit unit = this.Builder.GetOrBuildUnit(
-                power, location, this.Builder.Season, UnitType.Fleet);
+                power, location, this.SeasonContext.Season, UnitType.Fleet);
             return new ConvoyDestinationContext(this, unit);
         }
     }
@@ -385,6 +437,7 @@ public class TestCaseBuilder
     private class ConvoyDestinationContext : IConvoyDestinationContext
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public PowerContext PowerContext;
         public UnitContext UnitContext;
         public Unit Target;
@@ -392,6 +445,7 @@ public class TestCaseBuilder
         public ConvoyDestinationContext(ConvoyContext convoyContext, Unit target)
         {
             this.Builder = convoyContext.Builder;
+            this.SeasonContext = convoyContext.SeasonContext;
             this.PowerContext = convoyContext.PowerContext;
             this.UnitContext = convoyContext.UnitContext;
             this.Target = target;
@@ -404,7 +458,7 @@ public class TestCaseBuilder
                 this.PowerContext.Power,
                 this.UnitContext.Unit,
                 this.Target,
-                this.Builder.Season,
+                this.SeasonContext.Season,
                 location);
             this.Builder.OrderList.Add(order);
             return new OrderDefinedContext<ConvoyOrder>(this.UnitContext, order);
@@ -414,12 +468,14 @@ public class TestCaseBuilder
     private class SupportContext : ISupportContext
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public PowerContext PowerContext;
         public UnitContext UnitContext;
 
         public SupportContext(UnitContext unitContext)
         {
             this.Builder = unitContext.Builder;
+            this.SeasonContext = unitContext.SeasonContext;
             this.PowerContext = unitContext.PowerContext;
             this.UnitContext = unitContext;
         }
@@ -431,7 +487,7 @@ public class TestCaseBuilder
                 : this.Builder.World.GetPower(powerName);
             Location location = this.Builder.World.GetLand(provinceName);
             Unit unit = this.Builder.GetOrBuildUnit(
-                power, location, this.Builder.Season, UnitType.Army);
+                power, location, this.SeasonContext.Season, UnitType.Army);
             return new SupportTypeContext(this, unit);
         }
 
@@ -445,7 +501,7 @@ public class TestCaseBuilder
                 : this.Builder.World.GetPower(powerName);
             Location location = this.Builder.World.GetWater(provinceName, coast);
             Unit unit = this.Builder.GetOrBuildUnit(
-                power, location, this.Builder.Season, UnitType.Fleet);
+                power, location, this.SeasonContext.Season, UnitType.Fleet);
             return new SupportTypeContext(this, unit);
         }
     }
@@ -453,6 +509,7 @@ public class TestCaseBuilder
     private class SupportTypeContext : ISupportTypeContext
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public PowerContext PowerContext;
         public UnitContext UnitContext;
         public Unit Target;
@@ -460,6 +517,7 @@ public class TestCaseBuilder
         public SupportTypeContext(SupportContext supportContext, Unit target)
         {
             this.Builder = supportContext.Builder;
+            this.SeasonContext = supportContext.SeasonContext;
             this.PowerContext = supportContext.PowerContext;
             this.UnitContext = supportContext.UnitContext;
             this.Target = target;
@@ -484,7 +542,7 @@ public class TestCaseBuilder
                 this.PowerContext.Power,
                 this.UnitContext.Unit,
                 this.Target,
-                this.Builder.Season,
+                this.SeasonContext.Season,
                 destination);
             this.Builder.OrderList.Add(order);
             return new OrderDefinedContext<SupportMoveOrder>(this.UnitContext, order);
@@ -494,6 +552,7 @@ public class TestCaseBuilder
     private class OrderDefinedContext<OrderType> : IOrderDefinedContext<OrderType> where OrderType : Order
     {
         public TestCaseBuilder Builder;
+        public SeasonContext SeasonContext;
         public PowerContext PowerContext;
         public UnitContext UnitContext;
         public OrderType Order;
@@ -501,12 +560,17 @@ public class TestCaseBuilder
         public OrderDefinedContext(UnitContext unitContext, OrderType order)
         {
             this.Builder = unitContext.Builder;
+            this.SeasonContext = unitContext.SeasonContext;
             this.PowerContext = unitContext.PowerContext;
             this.UnitContext = unitContext;
             this.Order = order;
         }
 
-        public IPowerContext this[string powerName] => this.PowerContext[powerName];
+        public ISeasonContext this[(int turn, int timeline) seasonCoord]
+            => this.SeasonContext[seasonCoord];
+
+        public IPowerContext this[string powerName]
+            => this.SeasonContext[powerName];
 
         public IUnitContext Army(string provinceName, string? powerName = null)
             => this.PowerContext.Army(provinceName, powerName);

MultiversalDiplomacyTests/TestCaseBuilderTest.cs

@@ -27,18 +27,15 @@ class TestCaseBuilderTest
         Assert.That(setup.Orders, Is.Empty, "Expected no orders to be created yet");
         Assert.That(setup.World.Units, Is.Not.Empty, "Expected units to be created");
 
-        Unit armyLON = setup.World.GetUnitAt("London")
+        Unit armyLON = setup.World.GetUnitAt("London");
-            ?? throw new AssertionException("Expected a unit in London");
         Assert.That(armyLON.Power.Name, Is.EqualTo("England"), "Unit created with wrong power");
         Assert.That(armyLON.Type, Is.EqualTo(UnitType.Army), "Unit created with wrong type");
 
-        Unit fleetIRI = setup.World.GetUnitAt("Irish Sea")
+        Unit fleetIRI = setup.World.GetUnitAt("Irish Sea");
-            ?? throw new AssertionException("Expected a unit in Irish Sea");
         Assert.That(fleetIRI.Power.Name, Is.EqualTo("England"), "Unit created with wrong power");
         Assert.That(fleetIRI.Type, Is.EqualTo(UnitType.Fleet), "Unit created with wrong type");
 
-        Unit fleetSTP = setup.World.GetUnitAt("Saint Petersburg")
+        Unit fleetSTP = setup.World.GetUnitAt("Saint Petersburg");
-            ?? throw new AssertionException("Expected a unit in Saint Petersburg");
         Assert.That(fleetSTP.Power.Name, Is.EqualTo("Russia"), "Unit created with wrong power");
         Assert.That(fleetSTP.Type, Is.EqualTo(UnitType.Fleet), "Unit created with wrong type");
         Assert.That(

MultiversalDiplomacyTests/UnitTests.cs

@@ -14,7 +14,7 @@ public class UnitTests
             Boh = world.GetLand("Boh"),
             Tyr = world.GetLand("Tyr");
         Power pw1 = world.GetPower("Austria");
-        Season s1 = world.Seasons.First();
+        Season s1 = world.RootSeason;
         Unit u1 = Unit.Build(Mun, s1, pw1, UnitType.Army);
 
         Season s2 = s1.MakeNext();