Update tests/test_utils_typecast.py

tests/test_utils_typecast.py

@@ -22,9 +22,6 @@ class Car:
     def drive(self):
         return "vroom"
 
-
-# --- Tests ---
-
 def test_downcast_success():
     d = Dog()
     downcast(d, Bulldog)
@@ -33,7 +30,7 @@ def test_downcast_success():
 
 def test_upcast_success():
     b = Bulldog()
-    assert d.snore() == "woooooof"
+    assert b.snore() == "woooooof"
     assert not hasattr(d, "speak")
     upcast(b, Dog)
     assert b.speak() == "woof"
@@ -43,9 +40,11 @@ def test_upcast_success():
     assert b.speak() == "..."
 
 def test_downcast_invalid():
-    a = Animal()
+    class C: pass
+    class D: pass
+    c = C()
     with pytest.raises(TypeError, match="is not a subclass"):
-        downcast(a, Bulldog)
+        downcast(c, D)
 
 def test_upcast_invalid():
     c = Car()