Fix AttributeError: 'ClientConnectorCertificateError' object has no attribute '_os_error'.

ClientConnectorCertificateError is a subclass of ClientConnectorError and should have all of its
attributes (LSP). However, when I try to access the os_error attribute, I get the mentioned exception.

Author: themylogin

CHANGES/12136.bugfix.rst

@@ -0,0 +1,2 @@
+``ClientConnectorCertificateError.os_error`` no longer raises :exc:`AttributeError`
+-- by :user:`themylogin`.

CONTRIBUTORS.txt

@@ -392,6 +392,7 @@ Vladimir Kamarzin
 Vladimir Kozlovski
 Vladimir Rutsky
 Vladimir Shulyak
+Vladimir Vinogradenko
 Vladimir Zakharov
 Vladyslav Bohaichuk
 Vladyslav Bondar

aiohttp/client_exceptions.py

@@ -342,10 +342,12 @@ class ClientConnectorSSLError(*ssl_error_bases):  # type: ignore[misc]
 class ClientConnectorCertificateError(*cert_errors_bases):  # type: ignore[misc]
     """Response certificate error."""
 
+    _conn_key: ConnectionKey
+
     def __init__(
         self, connection_key: ConnectionKey, certificate_error: Exception
     ) -> None:
-        self._conn_key = connection_key
+        super().__init__(connection_key, OSError())
         self._certificate_error = certificate_error
         self.args = (connection_key, certificate_error)
 

tests/test_client_exceptions.py

@@ -201,6 +201,13 @@ def test_str(self) -> None:
             " [Exception: ('Bad certificate',)]"
         )
 
+    def test_oserror(self) -> None:
+        certificate_error = Exception("Bad certificate")
+        err = client.ClientConnectorCertificateError(
+            connection_key=self.connection_key, certificate_error=certificate_error
+        )
+        assert err.os_error == OSError()
+
 
 class TestServerDisconnectedError:
     def test_ctor(self) -> None: