More testing for log format name

src/cfnlint/rules/formats/LogGroupName.py

@@ -27,7 +27,7 @@ def format(self, validator: Validator, instance: Any) -> bool:
         if not isinstance(instance, str):
             return True
 
-        if re.match(r"^[.\-_/#A-Za-z0-9]{1,512}\Z", instance):
+        if re.match(r"^[\.\-_\/#A-Za-z0-9]{1,512}\Z", instance):
             return True
 
         return False

test/unit/rules/formats/test_log_group_name.py

@@ -0,0 +1,42 @@
+"""
+Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+SPDX-License-Identifier: MIT-0
+"""
+
+import pytest
+
+from cfnlint.rules.formats.LogGroupName import LogGroupName
+
+
+@pytest.fixture(scope="module")
+def rule():
+    rule = LogGroupName()
+    yield rule
+
+
+@pytest.mark.parametrize(
+    "name,instance,expected",
+    [
+        (
+            "Valid log group name",
+            "123457",
+            True,
+        ),
+        (
+            "Valid with invalid type",
+            [],
+            True,
+        ),
+        (
+            "Valid log group name with special characters",
+            "aws/one.two-three#four_five",
+            True,
+        ),
+        ("Invalid log group name because of special character", "foo&bar", False),
+        ("Invalid log group name because of empty", "", False),
+        ("Invalid log group name because too long", "a" * 513, False),
+    ],
+)
+def test_validate(name, instance, expected, rule, validator):
+    result = rule.format(validator, instance)
+    assert result == expected, f"Test {name!r} got {result!r}"