diff --git a/src/validators/slug.py b/src/validators/slug.py
index 2a02d20..7fdc67e 100644
--- a/src/validators/slug.py
+++ b/src/validators/slug.py
@@ -6,6 +6,8 @@
 # local
 from .utils import validator
 
+_SLUG_REGEXP = re.compile(r"^[a-z0-9]+(?:-[a-z0-9]+)*$")
+
 
 @validator
 def slug(value: str, /):
@@ -27,4 +29,4 @@ def slug(value: str, /):
         (Literal[True]): If `value` is a valid slug.
         (ValidationError): If `value` is an invalid slug.
     """
-    return re.match(r"^[a-z0-9]+(?:-[a-z0-9]+)*$", value) if value else False
+    return _SLUG_REGEXP.match(value) is not None
diff --git a/tests/test_slug.py b/tests/test_slug.py
index bcd4e26..5c62901 100644
--- a/tests/test_slug.py
+++ b/tests/test_slug.py
@@ -1,6 +1,9 @@
 """Test Slug."""
 
 # external
+
+from typing import Any
+
 import pytest
 
 # local
@@ -10,6 +13,35 @@
 @pytest.mark.parametrize(
     "value",
     [
+        # with numbers
+        "hello123",
+        "123hello",
+        "123",
+        # with hyphens
+        "hello-world",
+        "hello-world-test",
+        "test-123-abc",
+        # with mixed alphanumeric
+        "hello123-world456",
+        "123-456-789",
+        "a1-b2-c3",
+        # with single character
+        "a",
+        "1",
+        "z",
+        # with complex slug
+        "test-123-abc-456-def",
+        "this-is-a-very-long-slug-with-many-words",
+        # with multiple hyphens
+        "a-b-c",
+        "1-2-3",
+        # very long
+        "a" * 100,
+        # very long with hyphens
+        "a-" * 50 + "end",
+        # very long with hyphens and different alphabets|letters
+        "a1-b2-c3-d4-e5-f6-g7-h8-i9-j0",
+        # old
         "123-asd-7sda",
         "123-k-123",
         "dac-12sa-459",
@@ -24,6 +56,46 @@ def test_returns_true_on_valid_slug(value: str):
 @pytest.mark.parametrize(
     "value",
     [
+        # with empty_string
+        "",
+        # with upper case
+        "Hello",
+        "HELLO",
+        "hello-World",
+        "Test-Slug",
+        # with special characters
+        "hello world",
+        "hello_world",
+        "hello.world",
+        "hello@world",
+        "hello#world",
+        "hello$world",
+        # starting with hyphen
+        "-hello",
+        "-123",
+        "-hello-world",
+        # with consecutive hyphens
+        "hello--world",
+        "test---slug",
+        "a--b",
+        # with unicode characters
+        "café",
+        "привет",
+        "東京",
+        "hello-мир",
+        # with spaces
+        "hello world",
+        " hello ",
+        "hello  world",
+        # with only hyphens
+        "-",
+        "--",
+        "---",
+        # with mixed case
+        "HelloWorld",
+        "helloWorld",
+        "HELLOworld",
+        # old
         "some.slug&",
         "1231321%",
         "   21312",
@@ -33,3 +105,36 @@ def test_returns_true_on_valid_slug(value: str):
 def test_returns_failed_validation_on_invalid_slug(value: str):
     """Test returns failed validation on invalid slug."""
     assert isinstance(slug(value), ValidationError)
+
+
+@pytest.mark.parametrize(
+    ("val", "input_type"),
+    [
+        (1, "int"),
+        (1.0, "float"),
+        (None, "NoneType"),
+        ([], "list"),
+        ((), "tuple"),
+        ({}, "dict"),
+    ],
+)
+def test_non_string_input(val: Any, input_type: Any):
+    """Test with non string input."""
+    # given
+    message = f"expected string or bytes-like object, got '{input_type}'"
+    # when
+    result = slug(val)
+    # then
+    assert isinstance(result, ValidationError)
+    assert result.reason == message
+
+
+def test_slug_function_signature():
+    """Test with keyword argument."""
+    # given
+    message = "slug() got some positional-only arguments passed as keyword arguments: 'value'"
+    # when
+    result = slug(value="test-slug")
+    # then
+    assert isinstance(result, ValidationError)
+    assert result.reason == message