Allow variadic tuples of length 0. Fixes #104

.gitignore

@@ -95,3 +95,6 @@ venv/
 ENV/
 env.bak/
 venv.bak/
+
+# File created by pytest
+testing.json

dataclass_wizard/parsers.py

@@ -401,10 +401,7 @@ def __post_init__(self, cls: Type,
         # Total count should be `Infinity` here, since the variadic form
         # accepts any number of possible arguments.
         self.total_count: N = float('inf')
-        # Check for the count of parsers which don't handle `NoneType` - this
-        # should exclude the parsers for `Union` types that have `None` in the
-        # list of args.
-        self.required_count = 0 if None in self.first_elem_parser[0] else 1
+        self.required_count = 0
 
     def __call__(self, o: M) -> M:
         """

tests/unit/test_load.py

@@ -1150,6 +1150,8 @@ class MyClass(JSONSerializable):
             # conversion to `int` still succeeds. Might need to change this
             # behavior later if needed.
             [{}], does_not_raise(), (0, )),
+        (
+            [], does_not_raise(), tuple()),
         (
             [True, False, True], pytest.raises(TypeError), None),
         (