Fix domain validation in Tesla Fleet (home-assistant#148555)

Author: jlestel

homeassistant/components/tesla_fleet/config_flow.py

@@ -226,5 +226,7 @@ async def async_step_reauth_confirm(
     def _is_valid_domain(self, domain: str) -> bool:
         """Validate domain format."""
         # Basic domain validation regex
-        domain_pattern = re.compile(r"^(?:[a-zA-Z0-9]+\.)+[a-zA-Z0-9-]+$")
+        domain_pattern = re.compile(
+            r"^(?:[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$"
+        )
         return bool(domain_pattern.match(domain))

tests/components/tesla_fleet/test_config_flow.py

@@ -713,15 +713,20 @@ async def test_reauth_confirm_form(hass: HomeAssistant) -> None:
     ("domain", "expected_valid"),
     [
         ("example.com", True),
+        ("exa-mple.com", True),
         ("test.example.com", True),
+        ("tes-t.example.com", True),
         ("sub.domain.example.org", True),
+        ("su-b.dom-ain.exam-ple.org", True),
         ("https://example.com", False),
         ("invalid-domain", False),
         ("", False),
         ("example", False),
         ("example.", False),
         (".example.com", False),
         ("exam ple.com", False),
+        ("-example.com", False),
+        ("domain-.example.com", False),
     ],
 )
 def test_is_valid_domain(domain: str, expected_valid: bool) -> None: