feat: Allow none as default parameter (#10)

* feat: allow None as default parameter

* chore: push version

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "eidos"
-version = "0.99.2"
+version = "0.99.3"
 authors = [
   { name="José F. Aldana Martín", email="jfaldanam@uma.es" },
 ]

src/eidos/validation/schema.py

@@ -59,13 +59,19 @@ def validate_input_schema(
         if required is None or required:  # If required is None, it is defined as True
             if schema_name not in arguments:
                 raise ValueError(f"Argument {schema_name} not found in arguments")
+
+            if not validate_type(arguments[schema_name], type_, allow_none=False):
+                raise TypeError(
+                    f"Argument {schema_name} is not of type {type_}. "
+                    f"Got {type(arguments[schema_name])} instead."
+                )
         else:  # If required is False, add the default value
             if schema_name not in arguments:
                 arguments[schema_name] = parameter["default"]
-        if not validate_type(arguments[schema_name], type_):
-            raise TypeError(
-                f"Argument {schema_name} is not of type {type_}. Either change the "
-                "default or provide an alternative value"
-            )
-
+            # None must be a valid type if it's marked as default.
+            if not validate_type(arguments[schema_name], type_, allow_none=True):
+                raise TypeError(
+                    f"Argument {schema_name} is not of type {type_}. "
+                    f"Got {type(arguments[schema_name])} instead."
+                )
     return arguments

src/eidos/validation/type.py

@@ -20,14 +20,18 @@ def split_type_from_generic(type_: str) -> tuple[str, str | None]:
     return main_type, generic_type
 
 
-def validate_type(value: Any, type_: str) -> bool:
+def validate_type(value: Any, type_: str, allow_none: bool = False) -> bool:
     """Validate the type of a value.
     Args:
         value (Any): Value to validate.
         type (str): Type to validate the value against.
+        allow_none (bool): Whether to allow None as a valid value.
     Returns:
         bool: True if the value is of the specified type, False otherwise.
     """
+    if allow_none:
+        if value is None:
+            return True
 
     main_type, generic_type = split_type_from_generic(type_)
     if generic_type and main_type == "list":