chore: update based on feedback

Author: jackwotherspoon

google/cloud/sql/connector/exceptions.py

@@ -77,3 +77,10 @@ class DnsResolutionError(Exception):
     Exception to be raised when an instance connection name can not be resolved
     from a DNS record.
     """
+
+
+class CacheClosedError(Exception):
+    """
+    Exception to be raised when a ConnectionInfoCache can not be accessed after
+    it is closed.
+    """

google/cloud/sql/connector/monitored_cache.py

@@ -19,6 +19,7 @@
 
 from google.cloud.sql.connector.connection_info import ConnectionInfo
 from google.cloud.sql.connector.connection_info import ConnectionInfoCache
+from google.cloud.sql.connector.exceptions import CacheClosedError
 from google.cloud.sql.connector.instance import RefreshAheadCache
 from google.cloud.sql.connector.lazy import LazyRefreshCache
 from google.cloud.sql.connector.resolver import DefaultResolver
@@ -95,9 +96,16 @@ async def _check_domain_name(self) -> None:
             )
 
     async def connect_info(self) -> ConnectionInfo:
+        if self.closed:
+            raise CacheClosedError(
+                "Can not get connection info, cache has already been closed."
+            )
         return await self.cache.connect_info()
 
     async def force_refresh(self) -> None:
+        # if cache is closed do not refresh
+        if self.closed:
+            return
         return await self.cache.force_refresh()
 
     async def close(self) -> None:

tests/unit/test_monitored_cache.py

@@ -25,6 +25,7 @@
 
 from google.cloud.sql.connector.client import CloudSQLClient
 from google.cloud.sql.connector.connection_name import ConnectionName
+from google.cloud.sql.connector.exceptions import CacheClosedError
 from google.cloud.sql.connector.lazy import LazyRefreshCache
 from google.cloud.sql.connector.monitored_cache import MonitoredCache
 from google.cloud.sql.connector.resolver import DefaultResolver
@@ -65,6 +66,28 @@ async def test_MonitoredCache_properties(fake_client: CloudSQLClient) -> None:
     assert monitored_cache.closed is True
 
 
+async def test_MonitoredCache_CacheClosedError(fake_client: CloudSQLClient) -> None:
+    """
+    Test that MonitoredCache.connect_info errors when cache is closed.
+    """
+    conn_name = ConnectionName("test-project", "test-region", "test-instance")
+    cache = LazyRefreshCache(
+        conn_name,
+        client=fake_client,
+        keys=asyncio.create_task(generate_keys()),
+        enable_iam_auth=False,
+    )
+    monitored_cache = MonitoredCache(cache, 30, DefaultResolver())
+    # test closed property
+    assert monitored_cache.closed is False
+    # close cache and make sure property is updated
+    await monitored_cache.close()
+    assert monitored_cache.closed is True
+    # attempt to get connect info from closed cache
+    with pytest.raises(CacheClosedError):
+        await monitored_cache.connect_info()
+
+
 async def test_MonitoredCache_with_DnsResolver(fake_client: CloudSQLClient) -> None:
     """
     Test that MonitoredCache with DnsResolver work as expected.