add tests

reflex/utils/types.py

@@ -195,6 +195,8 @@ def unionize(*args: GenericType) -> Type:
         return Any
     if len(args) == 1:
         return args[0]
+    if sys.version_info >= (3, 11):
+        return Union[*args]  # type: ignore
     # We are bisecting the args list here to avoid hitting the recursion limit
     # In Python versions >= 3.11, we can simply do `return Union[*args]`
     midpoint = len(args) // 2

tests/units/test_var.py

@@ -398,6 +398,31 @@ def test_list_tuple_contains(var, expected):
     assert str(var.contains(other_var)) == f"{expected}.includes(other)"
 
 
+class Foo(rx.Base):
+    bar: int
+    baz: str
+
+
+class Bar(rx.Base):
+    bar: str
+    baz: str
+    foo: int
+
+
+@pytest.mark.parametrize(
+    ("var", "var_type"),
+    [
+        (Var(_js_expr="", _var_type=Foo | Bar).guess_type(), Foo | Bar),
+        (Var(_js_expr="", _var_type=Union[Foo, Bar]).guess_type(), Union[Foo, Bar]),
+        (Var(_js_expr="", _var_type=Union[Foo, Bar]).guess_type().bar, Union[int, str]),
+        (Var(_js_expr="", _var_type=Union[Foo, Bar]).guess_type().baz, str),
+        (Var(_js_expr="", _var_type=Union[Foo, Bar]).guess_type().foo, Union[int, None]),
+    ],
+)
+def test_var_types(var, var_type):
+    assert var._var_type == var_type
+
+
 @pytest.mark.parametrize(
     "var, expected",
     [