import requests
from requests.exceptions import InvalidURL


def test_leading_dot_hostname_raises_invalid_url():
    s = requests.Session()
    s.trust_env = False
    try:
        s.get("http://.example.com", timeout=5)
    except InvalidURL:
        pass
    except Exception as e:
        assert False, f"Expected InvalidURL, got {type(e).__name__}: {e}"
    else:
        assert False, "Expected InvalidURL for http://.example.com"
