More tests, more fixes

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

@@ -0,0 +1,92 @@
+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="Covet"/> move script.
+/// Gen VII Bulbapedia behavior: "Covet inflicts damage and steals the target's held item if it is holding
+/// any. If the target is not holding an item or the user is already holding an item, Covet cannot steal an
+/// item."
+/// </summary>
+public class CovetTests
+{
+    private static (Covet script, IExecutingMove move, IPokemon user, IPokemon target) CreateTestSetup(
+        IItem? targetItem)
+    {
+        var script = new Covet();
+        var move = Substitute.For<IExecutingMove>();
+        var user = Substitute.For<IPokemon>();
+        // Explicitly return null to suppress NSubstitute's auto-substitution; Covet must see an empty-handed user.
+        user.HeldItem.Returns((IItem?)null);
+        move.User.Returns(user);
+
+        var target = Substitute.For<IPokemon>();
+        target.HeldItem.Returns(targetItem);
+        if (targetItem != null)
+        {
+            target.TryStealHeldItem(out Arg.Any<IItem?>()).Returns(x =>
+            {
+                x[0] = targetItem;
+                return true;
+            });
+        }
+
+        return (script, move, user, target);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "Covet inflicts damage and steals the target's held item if it is holding any." The
+    /// item is removed from the target and ends up held by the user.
+    /// </summary>
+    [Test]
+    public void OnSecondaryEffect_TargetHoldsItem_UserStealsIt()
+    {
+        // Arrange
+        var item = Substitute.For<IItem>();
+        var (script, move, user, target) = CreateTestSetup(item);
+
+        // Act
+        script.OnSecondaryEffect(move, target, 0);
+
+        // Assert - the item is taken from the target and given to the user
+        target.Received(1).TryStealHeldItem(out Arg.Any<IItem?>());
+        user.Received(1).ForceSetHeldItem(item);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "If the target is not holding an item [...], Covet cannot steal an item."
+    /// </summary>
+    [Test]
+    public void OnSecondaryEffect_TargetHoldsNoItem_NothingIsStolen()
+    {
+        // Arrange
+        var (script, move, user, target) = CreateTestSetup(null);
+
+        // Act
+        script.OnSecondaryEffect(move, target, 0);
+
+        // Assert
+        target.DidNotReceive().TryStealHeldItem(out Arg.Any<IItem?>());
+        user.DidNotReceive().ForceSetHeldItem(Arg.Any<IItem?>());
+    }
+
+    /// <summary>
+    /// Bulbapedia: "If [...] the user is already holding an item, Covet cannot steal an item."
+    /// </summary>
+    [Test]
+    public void OnSecondaryEffect_UserAlreadyHoldsItem_TargetItemIsNotStolen()
+    {
+        // Arrange
+        var targetItem = Substitute.For<IItem>();
+        var (script, move, user, target) = CreateTestSetup(targetItem);
+        user.HeldItem.Returns(Substitute.For<IItem>());
+
+        // Act
+        script.OnSecondaryEffect(move, target, 0);
+
+        // Assert - the user must not end up with the target's item
+        user.DidNotReceive().ForceSetHeldItem(targetItem);
+    }
+}