[Test]
public void LowerLifeWhenHitByBullet()
{
    enemy = new EnemyPlane(new Vector2D(1.2f, 0.5f));
    Assert.AreEqual(5, enemy.Hitpoints);
    enemy.CheckIfHitAndReact(new Vector2D(1.2f, 0.5f));
    Assert.AreEqual(4, enemy.Hitpoints);
}

[Test]
public void LowerLifeWhenHitByBullet()
{
    enemy = new EnemyPlane(new Vector2D(1.2f, 0.5f));
    Assert.AreEqual(5, enemy.Hitpoints);
    enemy.CheckIfHitAndReact(new Vector2D(1.2f, 0.5f));
    Assert.AreEqual(4, enemy.Hitpoints);
}

[Test]
public void DefeatEnemyPlane()
{
    enemy = new EnemyPlane(new Vector2D(1.2f, 0.9f));
    bool defeated = false;
    enemy.Destroyed += () => { defeated = true; };
    enemy.ReceiveAttack(5);
    Assert.LessOrEqual(enemy.Hitpoints, 0);
    Assert.IsTrue(defeated);
}

[Test]
public void DefeatEnemyPlane()
{
    enemy = new EnemyPlane(new Vector2D(1.2f, 0.9f));
    bool defeated = false;
    enemy.Destroyed += () => { defeated = true; };
    enemy.ReceiveAttack(5);
    Assert.LessOrEqual(enemy.Hitpoints, 0);
    Assert.IsTrue(defeated);
}

[Test]
public void EnemyDespawnsOutsideScreenArea()
{
    enemy = new EnemyPlane(new Vector2D(ScreenSpace.Current.Left - enemy.DrawArea.Width, 0.5f));
    AdvanceTimeAndUpdateEntities();
    Assert.IsFalse(enemy.IsActive);
}

[Test]
public void EnemyDespawnsOutsideScreenArea()
{
    enemy = new EnemyPlane(new Vector2D(ScreenSpace.Current.Left - enemy.DrawArea.Width, 0.5f));
    AdvanceTimeAndUpdateEntities();
    Assert.IsFalse(enemy.IsActive);
}