card_game/tests/Game.Core.Tests/PhaseBTests.cs

using CardGame.Core;
using Xunit;

namespace Game.Core.Tests;

public sealed class PhaseBTests
{
    private static GameState NewMatch(CardDefinition card, int count = 10) =>
        MatchSetup.Create(11, Cards.Repeat(card, count), Cards.Repeat(card, count), Cards.Catalog, shuffle: false);

    [Fact]
    public void Opening_draw_and_base_supply()
    {
        var state = NewMatch(Cards.Wisp);
        Assert.Equal(4, state.Players[0].Hand.Count);
        Assert.Equal(3, state.Players[1].Hand.Count);
        Assert.Equal(1, state.Players[0].Energy);
    }

    [Fact]
    public void Play_creature_pays_current_cost()
    {
        var state = NewMatch(Cards.Wisp);
        var wisp = state.Players[0].Hand[0];
        state = RulesEngine.Execute(state, new PlayCardAction(0, wisp.Id));
        Assert.Equal(0, state.Players[0].Energy);
        Assert.Contains(state.Board, e => e.Id == wisp.Id && e.Zone == Zone.Board);
        Assert.Equal(0, state.Find(wisp.Id)!.AttacksRemaining);
    }

    [Fact]
    public void Spell_damages_and_goes_to_graveyard()
    {
        var state = NewMatch(Cards.Spark);
        var spark = state.Players[0].Hand[0];
        state = RulesEngine.Execute(state, new PlayCardAction(0, spark.Id, new PlayerTarget(1)));
        Assert.Equal(19, state.Players[1].Life);
        Assert.Contains(state.Players[0].Graveyard, e => e.Id == spark.Id);
    }

    [Fact]
    public void Creature_attacks_after_summoning_sickness()
    {
        var state = NewMatch(Cards.Wisp, 20);
        var wisp = state.Players[0].Hand[0];
        state = RulesEngine.Execute(state, new PlayCardAction(0, wisp.Id));
        Assert.DoesNotContain(RulesEngine.GetLegalActions(state), a => a is AttackAction);

        state = RulesEngine.Execute(state, new EndTurnAction(0));
        state = RulesEngine.Execute(state, new EndTurnAction(1));

        var attacker = state.Board.Single(e => e.ControllerIndex == 0 && e.Definition.Id == Cards.Wisp.Id);
        state = RulesEngine.Execute(state, new AttackAction(0, attacker.Id, new PlayerTarget(1)));
        Assert.Equal(19, state.Players[1].Life);
    }

    [Fact]
    public void Shared_board_caps_at_ten()
    {
        var state = NewMatch(Cards.Wisp, 30);
        for (var turn = 0; turn < 8 && !state.IsOver; turn++)
        {
            while (true)
            {
                var play = RulesEngine.GetLegalActions(state).OfType<PlayCardAction>().FirstOrDefault();
                if (play is null)
                {
                    break;
                }

                state = RulesEngine.Execute(state, play);
            }

            if (state.IsOver)
            {
                break;
            }

            state = RulesEngine.Execute(state, new EndTurnAction(state.ActivePlayerIndex));
        }

        Assert.True(state.Board.Count(e => e.Definition.Type != CardType.FieldCard || !e.IsSystem) <= GameState.BoardCapacity);
    }
}