Many more tests and fixes

Plugins/PkmnLib.Plugin.Gen7.Tests/Scripts/Moves/FellStingerTests.cs

@@ -0,0 +1,116 @@
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Plugin.Gen7.Scripts.Moves;
+using PkmnLib.Static;
+
+namespace PkmnLib.Plugin.Gen7.Tests.Scripts.Moves;
+
+/// <summary>
+/// Tests for the <see cref="FellStinger"/> move script.
+/// Gen VII Bulbapedia behavior ("Generation VII onwards"): "It now raises the user's Attack stat by three
+/// stages if it causes the targeted Pokémon to faint."
+/// </summary>
+public class FellStingerTests
+{
+    /// <summary>
+    /// Creates a fully mocked test setup for Fell Stinger tests.
+    /// </summary>
+    private static (FellStinger script, IExecutingMove move, IPokemon user, IPokemon target) CreateTestSetup(
+        bool targetFainted)
+    {
+        var script = new FellStinger();
+        var move = Substitute.For<IExecutingMove>();
+        var user = Substitute.For<IPokemon>();
+        move.User.Returns(user);
+        var target = Substitute.For<IPokemon>();
+        target.IsFainted.Returns(targetFainted);
+        return (script, move, user, target);
+    }
+
+    /// <summary>
+    /// Helper to find the first ChangeStatBoost call received by a Pokémon substitute.
+    /// </summary>
+    private static object[]? GetStatBoostArguments(IPokemon pokemon)
+    {
+        var call = pokemon.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "ChangeStatBoost");
+        return call?.GetArguments()!;
+    }
+
+    /// <summary>
+    /// Bulbapedia: "It now raises the user's Attack stat by three stages if it causes the targeted Pokémon
+    /// to faint."
+    /// When the target fainted from the hit, the user's Attack stat is boosted.
+    /// </summary>
+    [Test]
+    public async Task OnAfterHits_TargetFainted_RaisesUserAttack()
+    {
+        // Arrange
+        var (script, move, user, target) = CreateTestSetup(true);
+
+        // Act
+        script.OnAfterHits(move, target);
+
+        // Assert
+        var arguments = GetStatBoostArguments(user);
+        await Assert.That(arguments).IsNotNull();
+        await Assert.That((Statistic)arguments![0]!).IsEqualTo(Statistic.Attack);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "It now raises the user's Attack stat by three stages if it causes the targeted Pokémon
+    /// to faint."
+    /// In Generation VII the boost is three stages (up from two stages in Generation VI).
+    /// </summary>
+    [Test]
+    public async Task OnAfterHits_TargetFainted_AttackRaisedByThreeStages()
+    {
+        // Arrange
+        var (script, move, user, target) = CreateTestSetup(true);
+
+        // Act
+        script.OnAfterHits(move, target);
+
+        // Assert
+        var arguments = GetStatBoostArguments(user);
+        await Assert.That(arguments).IsNotNull();
+        await Assert.That((sbyte)arguments![1]!).IsEqualTo((sbyte)3);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "It now raises the user's Attack stat by three stages if it causes the targeted Pokémon
+    /// to faint."
+    /// The boost is applied by the user to itself, so it must be self-inflicted and not forced.
+    /// </summary>
+    [Test]
+    public async Task OnAfterHits_TargetFainted_BoostIsSelfInflictedAndNotForced()
+    {
+        // Arrange
+        var (script, move, user, target) = CreateTestSetup(true);
+
+        // Act
+        script.OnAfterHits(move, target);
+
+        // Assert
+        var arguments = GetStatBoostArguments(user);
+        await Assert.That(arguments).IsNotNull();
+        await Assert.That((bool)arguments![2]!).IsTrue();
+        await Assert.That((bool)arguments[3]!).IsFalse();
+    }
+
+    /// <summary>
+    /// Bulbapedia: the Attack boost only happens "if it causes the targeted Pokémon to faint".
+    /// If the target survives the hit, no stat boost is applied.
+    /// </summary>
+    [Test]
+    public async Task OnAfterHits_TargetNotFainted_NoStatBoost()
+    {
+        // Arrange
+        var (script, move, user, target) = CreateTestSetup(false);
+
+        // Act
+        script.OnAfterHits(move, target);
+
+        // Assert - ChangeStatBoost should never be called. (Checked via ReceivedCalls, as arg matchers cannot
+        // be used with EventBatchId parameters: its parameterless constructor generates a random Guid.)
+        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "ChangeStatBoost")).IsFalse();
+    }
+}