More unit tests, fixes

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

@@ -0,0 +1,69 @@
+using PkmnLib.Dynamic.Models;
+using PkmnLib.Plugin.Gen7.Scripts.Moves;
+
+namespace PkmnLib.Plugin.Gen7.Tests.Scripts.Moves;
+
+/// <summary>
+/// Tests for the <see cref="Explosion"/> move script.
+/// Gen VII Bulbapedia behavior: "the user faints upon using this move", and from Generation VI onwards
+/// "Explosion returns to damaging the target before the user faints."
+/// </summary>
+public class ExplosionTests
+{
+    private static (Explosion script, IExecutingMove move, IPokemon user) CreateTestSetup(uint currentHealth)
+    {
+        var script = new Explosion();
+        var move = Substitute.For<IExecutingMove>();
+        var user = Substitute.For<IPokemon>();
+        user.CurrentHealth.Returns(currentHealth);
+        move.User.Returns(user);
+        return (script, move, user);
+    }
+
+    /// <summary>
+    /// Helper to extract the damage amount from the user's received Damage calls.
+    /// </summary>
+    private static uint? GetDamageAmount(IPokemon user)
+    {
+        var call = user.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "Damage");
+        return call != null ? (uint)call.GetArguments()[0]! : null;
+    }
+
+    /// <summary>
+    /// Bulbapedia: "the user faints upon using this move" — after the hits are dealt, the user takes at
+    /// least its full current HP in damage, guaranteeing it faints.
+    /// </summary>
+    [Test]
+    public async Task OnAfterHits_UserTakesAtLeastItsCurrentHealthInDamage()
+    {
+        // Arrange
+        var (script, move, user) = CreateTestSetup(100);
+
+        // Act
+        script.OnAfterHits(move, Substitute.For<IPokemon>());
+
+        // Assert
+        var damage = GetDamageAmount(user);
+        await Assert.That(damage).IsNotNull();
+        await Assert.That(damage!.Value).IsGreaterThanOrEqualTo(100u);
+    }
+
+    /// <summary>
+    /// Bulbapedia: "Sturdy, Focus Band, and Focus Sash do not prevent user fainting." The self-inflicted
+    /// faint is indirect damage (<see cref="DamageSource.Misc"/>), not move damage, so hold-on effects
+    /// that watch for move damage do not apply.
+    /// </summary>
+    [Test]
+    public async Task OnAfterHits_UsesMiscDamageSource()
+    {
+        // Arrange
+        var (script, move, user) = CreateTestSetup(100);
+
+        // Act
+        script.OnAfterHits(move, Substitute.For<IPokemon>());
+
+        // Assert
+        var call = user.ReceivedCalls().First(c => c.GetMethodInfo().Name == "Damage");
+        await Assert.That((DamageSource)call.GetArguments()[1]!).IsEqualTo(DamageSource.Misc);
+    }
+}