Many more tests and fixes

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

@@ -0,0 +1,108 @@
+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="GyroBall"/> move script.
+/// Gen VII Bulbapedia behavior: "Gyro Ball inflicts more damage the slower the user is compared to the
+/// target", with base power = min(150, 25 × target Speed / user Speed + 1).
+/// </summary>
+public class GyroBallTests
+{
+    private static (GyroBall script, IExecutingMove move, IPokemon target) CreateTestSetup(uint userSpeed,
+        uint targetSpeed)
+    {
+        var script = new GyroBall();
+        var move = Substitute.For<IExecutingMove>();
+
+        var user = Substitute.For<IPokemon>();
+        user.BoostedStats.Returns(new StatisticSet<uint>(100, 100, 100, 100, 100, userSpeed));
+        move.User.Returns(user);
+
+        var target = Substitute.For<IPokemon>();
+        target.BoostedStats.Returns(new StatisticSet<uint>(100, 100, 100, 100, 100, targetSpeed));
+
+        return (script, move, target);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "BasePower = min(150, 25 × CurrentSpeed(target) / CurrentSpeed(user) + 1)". Various
+    /// speed combinations, including the integer truncation of the division.
+    /// </summary>
+    [Test, Arguments(100u, 100u, (ushort)26), Arguments(100u, 50u, (ushort)13), Arguments(100u, 1u, (ushort)1),
+     Arguments(50u, 200u, (ushort)101)]
+    // 25 * 100 / 100 + 1
+    // 25 * 50 / 100 = 12 (truncated) + 1
+    // 25 * 1 / 100 = 0 (truncated) + 1
+    // 25 * 200 / 50 + 1
+    public async Task ChangeBasePower_SpeedComparison_FollowsFormula(uint userSpeed, uint targetSpeed,
+        ushort expectedPower)
+    {
+        // Arrange
+        var (script, move, target) = CreateTestSetup(userSpeed, targetSpeed);
+        ushort basePower = 5;
+
+        // Act
+        script.ChangeBasePower(move, target, 0, ref basePower);
+
+        // Assert
+        await Assert.That(basePower).IsEqualTo(expectedPower);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "The move reaches its maximum base power of 150" — a formula result just above the cap
+    /// is clamped to 150.
+    /// </summary>
+    [Test]
+    public async Task ChangeBasePower_FormulaExceedsCap_BasePowerCappedAt150()
+    {
+        // Arrange - 25 * 60 / 10 + 1 = 151
+        var (script, move, target) = CreateTestSetup(10, 60);
+        ushort basePower = 5;
+
+        // Act
+        script.ChangeBasePower(move, target, 0, ref basePower);
+
+        // Assert
+        await Assert.That(basePower).IsEqualTo((ushort)150);
+    }
+
+    /// <summary>
+    /// Bulbapedia: the base power is capped at 150 for any speed ratio. The implementation truncates the
+    /// formula result to a byte before applying the cap, so results above 255 wrap around and produce a
+    /// wrong power (25 × 100 / 4 + 1 = 626 wraps to 114).
+    /// </summary>
+    [Test]
+    public async Task ChangeBasePower_FormulaFarExceedsByteRange_BasePowerCappedAt150()
+    {
+        // Arrange - 25 * 100 / 4 + 1 = 626
+        var (script, move, target) = CreateTestSetup(4, 100);
+        ushort basePower = 5;
+
+        // Act
+        script.ChangeBasePower(move, target, 0, ref basePower);
+
+        // Assert
+        await Assert.That(basePower).IsEqualTo((ushort)150);
+    }
+
+    /// <summary>
+    /// Bulbapedia (Generation VI onwards): "If the user of Gyro Ball has a Speed stat that rounds down to
+    /// 0, the move's power is set to 1."
+    /// </summary>
+    [Test]
+    public async Task ChangeBasePower_UserSpeedIsZero_BasePowerIsOne()
+    {
+        // Arrange
+        var (script, move, target) = CreateTestSetup(0, 100);
+        ushort basePower = 5;
+
+        // Act
+        script.ChangeBasePower(move, target, 0, ref basePower);
+
+        // Assert
+        await Assert.That(basePower).IsEqualTo((ushort)1);
+    }
+}