refactor: replace aiofiles with asyncio.to_thread

google/cloud/sql/connector/connection_info.py

@@ -20,11 +20,10 @@
 import ssl
 from typing import Any, Optional, TYPE_CHECKING
 
-from aiofiles.tempfile import TemporaryDirectory
-
 from google.cloud.sql.connector.connection_name import ConnectionName
 from google.cloud.sql.connector.exceptions import CloudSQLIPTypeError
 from google.cloud.sql.connector.exceptions import TLSVersionError
+from google.cloud.sql.connector.utils import AsyncTemporaryDirectory
 from google.cloud.sql.connector.utils import write_to_file
 
 if TYPE_CHECKING:
@@ -108,7 +107,7 @@ async def create_ssl_context(self, enable_iam_auth: bool = False) -> ssl.SSLCont
         # tmpdir and its contents are automatically deleted after the CA cert
         # and ephemeral cert are loaded into the SSLcontext. The values
         # need to be written to files in order to be loaded by the SSLContext
-        async with TemporaryDirectory() as tmpdir:
+        async with AsyncTemporaryDirectory() as tmpdir:
             ca_filename, cert_filename, key_filename = await write_to_file(
                 tmpdir, self.server_ca_cert, self.client_cert, self.private_key
             )

google/cloud/sql/connector/utils.py

@@ -14,7 +14,9 @@
 limitations under the License.
 """
 
-import aiofiles
+import asyncio
+import tempfile
+
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import serialization
 from cryptography.hazmat.primitives.asymmetric import rsa
@@ -57,6 +59,33 @@ async def generate_keys() -> tuple[bytes, str]:
     return priv_key, pub_key
 
 
+class AsyncTemporaryDirectory:
+    """Async context manager wrapper around tempfile.TemporaryDirectory."""
+
+    async def __aenter__(self) -> str:
+        self.temp_dir = await asyncio.to_thread(tempfile.TemporaryDirectory)
+        return self.temp_dir.name
+
+    async def __aexit__(self, exc_type, exc_val, exc_tb) -> None:
+        await asyncio.to_thread(self.temp_dir.cleanup)
+
+
+def _write_files(
+    ca_filename: str,
+    serverCaCert: str,
+    cert_filename: str,
+    ephemeralCert: str,
+    key_filename: str,
+    priv_key: bytes,
+) -> None:
+    with open(ca_filename, "w+") as ca_out:
+        ca_out.write(serverCaCert)
+    with open(cert_filename, "w+") as ephemeral_out:
+        ephemeral_out.write(ephemeralCert)
+    with open(key_filename, "wb") as priv_out:
+        priv_out.write(priv_key)
+
+
 async def write_to_file(
     dir_path: str, serverCaCert: str, ephemeralCert: str, priv_key: bytes
 ) -> tuple[str, str, str]:
@@ -68,12 +97,15 @@ async def write_to_file(
     cert_filename = f"{dir_path}/cert.pem"
     key_filename = f"{dir_path}/priv.pem"
 
-    async with aiofiles.open(ca_filename, "w+") as ca_out:
-        await ca_out.write(serverCaCert)
-    async with aiofiles.open(cert_filename, "w+") as ephemeral_out:
-        await ephemeral_out.write(ephemeralCert)
-    async with aiofiles.open(key_filename, "wb") as priv_out:
-        await priv_out.write(priv_key)
+    await asyncio.to_thread(
+        _write_files,
+        ca_filename,
+        serverCaCert,
+        cert_filename,
+        ephemeralCert,
+        key_filename,
+        priv_key,
+    )
 
     return (ca_filename, cert_filename, key_filename)
 

pyproject.toml

@@ -41,7 +41,6 @@ classifiers = [
     "Operating System :: OS Independent",
 ]
 dependencies = [
-    "aiofiles",
     "aiohttp",
     "cryptography>=42.0.0",
     "dnspython>=2.0.0",

tests/conftest.py

@@ -15,13 +15,14 @@
 """
 
 import asyncio
+import inspect
 import os
 import socket
 import ssl
 from threading import Thread
 from typing import Any, AsyncGenerator
 
-from aiofiles.tempfile import TemporaryDirectory
+import aiohttp
 from aiohttp import web
 from cryptography.hazmat.primitives import serialization
 import pytest  # noqa F401 Needed to run the tests
@@ -32,9 +33,23 @@
 from google.cloud.sql.connector.client import CloudSQLClient
 from google.cloud.sql.connector.connection_name import ConnectionName
 from google.cloud.sql.connector.instance import RefreshAheadCache
+from google.cloud.sql.connector.utils import AsyncTemporaryDirectory
 from google.cloud.sql.connector.utils import generate_keys
 from google.cloud.sql.connector.utils import write_to_file
 
+# Monkeypatch aiohttp.ClientResponse.__init__ to support aioresponses with aiohttp >= 3.11/3.14
+_original_client_response_init = aiohttp.ClientResponse.__init__
+
+
+def _patched_client_response_init(self, *args, **kwargs):
+    sig = inspect.signature(_original_client_response_init)
+    if "stream_writer" in sig.parameters and "stream_writer" not in kwargs:
+        kwargs["stream_writer"] = kwargs.get("writer", None)
+    return _original_client_response_init(self, *args, **kwargs)
+
+
+aiohttp.ClientResponse.__init__ = _patched_client_response_init
+
 SCOPES = ["https://www.googleapis.com/auth/sqlservice.admin"]
 
 
@@ -101,7 +116,7 @@ async def start_proxy_server(instance: FakeCSQLInstance) -> None:
             format=serialization.PrivateFormat.TraditionalOpenSSL,
             encryption_algorithm=serialization.NoEncryption(),
         )
-        async with TemporaryDirectory() as tmpdir:
+        async with AsyncTemporaryDirectory() as tmpdir:
             server_filename, _, key_filename = await write_to_file(
                 tmpdir, instance.server_cert_pem, "", server_key_bytes
             )

tests/unit/mocks.py

@@ -23,7 +23,6 @@
 import ssl
 from typing import Any, Callable, Literal, Optional
 
-from aiofiles.tempfile import TemporaryDirectory
 from aiohttp import web
 from cryptography import x509
 from cryptography.hazmat.backends import default_backend
@@ -36,6 +35,7 @@
 from google.auth.credentials import TokenState
 
 from google.cloud.sql.connector.connector import _DEFAULT_UNIVERSE_DOMAIN
+from google.cloud.sql.connector.utils import AsyncTemporaryDirectory
 from google.cloud.sql.connector.utils import generate_keys
 from google.cloud.sql.connector.utils import write_to_file
 
@@ -205,7 +205,7 @@ async def create_ssl_context(instance: FakeCSQLInstance) -> ssl.SSLContext:
     context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
     context.check_hostname = False
     # load ssl.SSLContext with certs
-    async with TemporaryDirectory() as tmpdir:
+    async with AsyncTemporaryDirectory() as tmpdir:
         ca_filename, cert_filename, key_filename = await write_to_file(
             tmpdir, instance.server_cert_pem, ephemeral_cert, client_private
         )