Fix/align input validation

.github/workflows/python-tests.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
 
     steps:
       - name: Check out repository

README.md

@@ -21,7 +21,7 @@ lengths, or whether an identifier is real.
 
 ## Requirements
 
-- Python 3.8+
+- Python 3.10+
 - No third-party packages
 
 ## Quick Start
@@ -95,8 +95,9 @@ space  -  .  /  \  ,
 
 After normalization, the value must contain at least one digit and no other
 characters. `checksum`, `calculate_check_digit`, and `append_check_digit` raise
-`ValueError` for invalid input. `is_valid` catches that error and returns
-`False`, which makes it convenient for validation checks.
+`ValueError` for malformed strings and `TypeError` for unsupported input types.
+`is_valid` catches both errors and returns `False`, which makes it convenient
+for validation checks.
 
 ## Examples
 

luhn.py

@@ -2,17 +2,15 @@
 
 from __future__ import annotations
 
-from typing import Union
-
-NumberLike = Union[str, int]
+NumberLike = str | int
 REMOVE_CHARS = " -./\\,"
 DIGIT_CLEANUP_TABLE = str.maketrans("", "", REMOVE_CHARS)
 
 
 def _digits(value: NumberLike) -> str:
     """Return only digits, allowing spaces, hyphens, dots, slashes, backslashes, and commas as separators."""
     if isinstance(value, bool) or not isinstance(value, (str, int)):
-        raise ValueError("value must be a string or non-boolean integer")
+        raise TypeError("value must be a string or non-boolean integer")
 
     cleaned = str(value).strip().translate(DIGIT_CLEANUP_TABLE)
 
@@ -51,7 +49,7 @@ def is_valid(value: NumberLike) -> bool:
 
     try:
         is_valid_checksum = checksum(value) == 0
-    except ValueError:
+    except (TypeError, ValueError):
         return False
 
     return is_valid_checksum

pyproject.toml

@@ -1,5 +1,5 @@
 [project]
 name = "luhn-algorithm"
 version = "0.1.0"
-requires-python = ">=3.14"
+requires-python = ">=3.10"
 dependencies = []

test_luhn.py

@@ -38,7 +38,7 @@ def test_rejects_unsupported_types(self):
                 self.assertFalse(is_valid(value))
 
                 for function in (checksum, calculate_check_digit, append_check_digit):
-                    with self.assertRaises(ValueError):
+                    with self.assertRaises(TypeError):
                         function(value)