fix: use servername callback instead of sni callback

tests/test_cert_manager.py

@@ -161,24 +161,26 @@ class TestRegistry(BaseTestCase):
             lambda: self.cert_manager.get_key("example.com"),
         )
 
-    def test_sni_callback_no_host(self) -> None:
+    def test_servername_callback_no_host(self) -> None:
         self._make_self_signed("example.com")
         with (
             self.patch("ssl.create_default_context", count=0),
         ):
-            self.cert_manager.sni_callback(self.socket_mock, None, self.context_mock)
+            self.cert_manager.servername_callback(
+                self.socket_mock, None, self.context_mock
+            )
 
-    def test_sni_callback_fail(self) -> None:
+    def test_servername_callback_fail(self) -> None:
         self._make_self_signed("example.com")
         with (
             self.patch("shutil.which", count=3),
             self.patch("ssl.create_default_context", count=0),
         ):
-            self.cert_manager.sni_callback(
+            self.cert_manager.servername_callback(
                 self.socket_mock, "example.fr", self.context_mock
             )
 
-    def test_sni_callback_create_context(self) -> None:
+    def test_servername_callback_create_context(self) -> None:
         self._make_self_signed("example.com")
         with (
             self.patch("ssl.create_default_context", return_value=self.context_mock),
@@ -191,18 +193,18 @@ class TestRegistry(BaseTestCase):
             ),
             self.patch("shutil.which", count=0),
         ):
-            self.cert_manager.sni_callback(
+            self.cert_manager.servername_callback(
                 self.socket_mock, "example.com", self.context_mock
             )
 
-    def test_sni_callback_create_context_fail(self) -> None:
+    def test_servername_callback_create_context_fail(self) -> None:
         self._make_self_signed("example.com")
         with (
             self.patch("ssl.create_default_context", return_value=self.context_mock),
             self.patch("shutil.which", count=0),
         ):
             self.context_mock.load_cert_chain.side_effect = Exception
-            self.cert_manager.sni_callback(
+            self.cert_manager.servername_callback(
                 self.socket_mock, "example.com", self.context_mock
             )
             self.context_mock.load_cert_chain.assert_called_once_with(