Format connection errors in the same way everywhere

redis/asyncio/connection.py

@@ -27,6 +27,8 @@
 )
 from urllib.parse import ParseResult, parse_qs, unquote, urlparse
 
+from ..utils import format_error_message
+
 # the functionality is available in 3.11.x but has a major issue before
 # 3.11.3. See https://github.com/redis/redis-py/issues/2633
 if sys.version_info >= (3, 11, 3):
@@ -345,9 +347,8 @@ async def _connect(self):
     def _host_error(self) -> str:
         pass
 
-    @abstractmethod
     def _error_message(self, exception: BaseException) -> str:
-        pass
+        return format_error_message(self._host_error(), exception)
 
     async def on_connect(self) -> None:
         """Initialize the connection, authenticate and select a database"""
@@ -799,27 +800,6 @@ async def _connect(self):
     def _host_error(self) -> str:
         return f"{self.host}:{self.port}"
 
-    def _error_message(self, exception: BaseException) -> str:
-        # args for socket.error can either be (errno, "message")
-        # or just "message"
-
-        host_error = self._host_error()
-
-        if not exception.args:
-            # asyncio has a bug where on Connection reset by peer, the
-            # exception is not instanciated, so args is empty. This is the
-            # workaround.
-            # See: https://github.com/redis/redis-py/issues/2237
-            # See: https://github.com/python/cpython/issues/94061
-            return f"Error connecting to {host_error}. Connection reset by peer"
-        elif len(exception.args) == 1:
-            return f"Error connecting to {host_error}. {exception.args[0]}."
-        else:
-            return (
-                f"Error {exception.args[0]} connecting to {host_error}. "
-                f"{exception}."
-            )
-
 
 class SSLConnection(Connection):
     """Manages SSL connections to and from the Redis server(s).
@@ -971,20 +951,6 @@ async def _connect(self):
     def _host_error(self) -> str:
         return self.path
 
-    def _error_message(self, exception: BaseException) -> str:
-        # args for socket.error can either be (errno, "message")
-        # or just "message"
-        host_error = self._host_error()
-        if len(exception.args) == 1:
-            return (
-                f"Error connecting to unix socket: {host_error}. {exception.args[0]}."
-            )
-        else:
-            return (
-                f"Error {exception.args[0]} connecting to unix socket: "
-                f"{host_error}. {exception.args[1]}."
-            )
-
 
 FALSE_STRINGS = ("0", "F", "FALSE", "N", "NO")
 

redis/connection.py

@@ -39,6 +39,7 @@
     HIREDIS_AVAILABLE,
     HIREDIS_PACK_AVAILABLE,
     SSL_AVAILABLE,
+    format_error_message,
     get_lib_version,
     str_if_bytes,
 )
@@ -338,9 +339,8 @@ def _connect(self):
     def _host_error(self):
         pass
 
-    @abstractmethod
     def _error_message(self, exception):
-        pass
+        return format_error_message(self._host_error(), exception)
 
     def on_connect(self):
         "Initialize the connection, authenticate and select a database"
@@ -733,27 +733,6 @@ def _connect(self):
     def _host_error(self):
         return f"{self.host}:{self.port}"
 
-    def _error_message(self, exception):
-        # args for socket.error can either be (errno, "message")
-        # or just "message"
-
-        host_error = self._host_error()
-
-        if len(exception.args) == 1:
-            try:
-                return f"Error connecting to {host_error}. \
-                        {exception.args[0]}."
-            except AttributeError:
-                return f"Connection Error: {exception.args[0]}"
-        else:
-            try:
-                return (
-                    f"Error {exception.args[0]} connecting to "
-                    f"{host_error}. {exception.args[1]}."
-                )
-            except AttributeError:
-                return f"Connection Error: {exception.args[0]}"
-
 
 class SSLConnection(Connection):
     """Manages SSL connections to and from the Redis server(s).
@@ -930,20 +909,6 @@ def _connect(self):
     def _host_error(self):
         return self.path
 
-    def _error_message(self, exception):
-        # args for socket.error can either be (errno, "message")
-        # or just "message"
-        host_error = self._host_error()
-        if len(exception.args) == 1:
-            return (
-                f"Error connecting to unix socket: {host_error}. {exception.args[0]}."
-            )
-        else:
-            return (
-                f"Error {exception.args[0]} connecting to unix socket: "
-                f"{host_error}. {exception.args[1]}."
-            )
-
 
 FALSE_STRINGS = ("0", "F", "FALSE", "N", "NO")
 

redis/utils.py

@@ -141,3 +141,15 @@ def get_lib_version():
     except metadata.PackageNotFoundError:
         libver = "99.99.99"
     return libver
+
+
+def format_error_message(host_error: str, exception: BaseException) -> str:
+    if not exception.args:
+        return f"Error connecting to {host_error}."
+    elif len(exception.args) == 1:
+        return f"Error {exception.args[0]} connecting to {host_error}."
+    else:
+        return (
+            f"Error {exception.args[0]} connecting to {host_error}. "
+            f"{exception.args[1]}."
+        )

tests/test_asyncio/test_connection.py

@@ -12,7 +12,12 @@
     _AsyncRESPBase,
 )
 from redis.asyncio import ConnectionPool, Redis
-from redis.asyncio.connection import Connection, UnixDomainSocketConnection, parse_url
+from redis.asyncio.connection import (
+    Connection,
+    SSLConnection,
+    UnixDomainSocketConnection,
+    parse_url,
+)
 from redis.asyncio.retry import Retry
 from redis.backoff import NoBackoff
 from redis.exceptions import ConnectionError, InvalidResponse, TimeoutError
@@ -494,18 +499,50 @@ async def test_connection_garbage_collection(request):
 
 
 @pytest.mark.parametrize(
-    "error, expected_message",
+    "conn, error, expected_message",
     [
-        (OSError(), "Error connecting to localhost:6379. Connection reset by peer"),
-        (OSError(12), "Error connecting to localhost:6379. 12."),
+        (SSLConnection(), OSError(), "Error connecting to localhost:6379."),
+        (SSLConnection(), OSError(12), "Error 12 connecting to localhost:6379."),
         (
+            SSLConnection(),
             OSError(12, "Some Error"),
-            "Error 12 connecting to localhost:6379. [Errno 12] Some Error.",
+            "Error 12 connecting to localhost:6379. Some Error.",
+        ),
+        (
+            UnixDomainSocketConnection(path="unix:///tmp/redis.sock"),
+            OSError(),
+            "Error connecting to unix:///tmp/redis.sock.",
+        ),
+        (
+            UnixDomainSocketConnection(path="unix:///tmp/redis.sock"),
+            OSError(12),
+            "Error 12 connecting to unix:///tmp/redis.sock.",
+        ),
+        (
+            UnixDomainSocketConnection(path="unix:///tmp/redis.sock"),
+            OSError(12, "Some Error"),
+            "Error 12 connecting to unix:///tmp/redis.sock. Some Error.",
         ),
     ],
 )
-async def test_connect_error_message(error, expected_message):
+async def test_format_error_message(conn, error, expected_message):
     """Test that the _error_message function formats errors correctly"""
-    conn = Connection()
     error_message = conn._error_message(error)
     assert error_message == expected_message
+
+
+async def test_network_connection_failure():
+    with pytest.raises(ConnectionError) as e:
+        redis = Redis(host="127.0.0.1", port=9999)
+        await redis.set("a", "b")
+    assert str(e.value).startswith("Error 111 connecting to 127.0.0.1:9999. Connect")
+
+
+async def test_unix_socket_connection_failure():
+    with pytest.raises(ConnectionError) as e:
+        redis = Redis(unix_socket_path="unix:///tmp/a.sock")
+        await redis.set("a", "b")
+    assert (
+        str(e.value)
+        == "Error 2 connecting to unix:///tmp/a.sock. No such file or directory."
+    )

tests/test_connection.py

@@ -296,3 +296,53 @@ def mock_disconnect(_):
 
     assert called == 1
     pool.disconnect()
+
+
+@pytest.mark.parametrize(
+    "conn, error, expected_message",
+    [
+        (SSLConnection(), OSError(), "Error connecting to localhost:6379."),
+        (SSLConnection(), OSError(12), "Error 12 connecting to localhost:6379."),
+        (
+            SSLConnection(),
+            OSError(12, "Some Error"),
+            "Error 12 connecting to localhost:6379. Some Error.",
+        ),
+        (
+            UnixDomainSocketConnection(path="unix:///tmp/redis.sock"),
+            OSError(),
+            "Error connecting to unix:///tmp/redis.sock.",
+        ),
+        (
+            UnixDomainSocketConnection(path="unix:///tmp/redis.sock"),
+            OSError(12),
+            "Error 12 connecting to unix:///tmp/redis.sock.",
+        ),
+        (
+            UnixDomainSocketConnection(path="unix:///tmp/redis.sock"),
+            OSError(12, "Some Error"),
+            "Error 12 connecting to unix:///tmp/redis.sock. Some Error.",
+        ),
+    ],
+)
+def test_format_error_message(conn, error, expected_message):
+    """Test that the _error_message function formats errors correctly"""
+    error_message = conn._error_message(error)
+    assert error_message == expected_message
+
+
+def test_network_connection_failure():
+    with pytest.raises(ConnectionError) as e:
+        redis = Redis(port=9999)
+        redis.set("a", "b")
+    assert str(e.value) == "Error 111 connecting to localhost:9999. Connection refused."
+
+
+def test_unix_socket_connection_failure():
+    with pytest.raises(ConnectionError) as e:
+        redis = Redis(unix_socket_path="unix:///tmp/a.sock")
+        redis.set("a", "b")
+    assert (
+        str(e.value)
+        == "Error 2 connecting to unix:///tmp/a.sock. No such file or directory."
+    )