Fix AWS S3 config flow endpoint URL validation (#164085)

Co-authored-by: mik-laj <12058428+mik-laj@users.noreply.github.com>

homeassistant/components/aws_s3/config_flow.py

@@ -60,9 +60,8 @@ class S3ConfigFlow(ConfigFlow, domain=DOMAIN):
                 }
             )
 
-            if not urlparse(user_input[CONF_ENDPOINT_URL]).hostname.endswith(
-                AWS_DOMAIN
-            ):
+            hostname = urlparse(user_input[CONF_ENDPOINT_URL]).hostname
+            if not hostname or not hostname.endswith(AWS_DOMAIN):
                 errors[CONF_ENDPOINT_URL] = "invalid_endpoint_url"
             else:
                 try:

tests/components/aws_s3/test_config_flow.py

@@ -122,12 +122,19 @@ async def test_abort_if_already_configured(
     assert result["reason"] == "already_configured"
 
 
+@pytest.mark.parametrize(
+    ("endpoint_url"),
+    [
+        ("@@@"),
+        ("http://example.com"),
+    ],
+)
 async def test_flow_create_not_aws_endpoint(
-    hass: HomeAssistant,
+    hass: HomeAssistant, endpoint_url: str
 ) -> None:
     """Test config flow with a not aws endpoint should raise an error."""
     result = await _async_start_flow(
-        hass, USER_INPUT | {CONF_ENDPOINT_URL: "http://example.com"}
+        hass, USER_INPUT | {CONF_ENDPOINT_URL: endpoint_url}
     )
 
     assert result["type"] is FlowResultType.FORM