Strengthen is_connected with cached health probes.

Convert is_connected to a method that verifies backend liveness via TTL-cached ping (Redis) or bucket_exists (MinIO), with cache invalidation on connect/disconnect.

Co-authored-by: Cursor <[email protected]>

tests/integration/connection_aware_interface_test.py

@@ -15,7 +15,6 @@ def test_instantiation_fails_when_connect_not_implemented() -> None:
         def disconnect(self) -> None:
             pass
 
-        @property
         def is_connected(self) -> bool:
             return False
 
@@ -32,7 +31,6 @@ def test_instantiation_fails_when_disconnect_not_implemented() -> None:
         def connect(self) -> None:
             pass
 
-        @property
         def is_connected(self) -> bool:
             return False
 

tests/integration/minio_adapter_test.py

@@ -115,7 +115,7 @@ def test_should_have_logger_when_instantiated() -> None:
 def test_should_not_be_connected_when_instantiated() -> None:
     """Test that the MinioAdapter is not connected when instantiated."""
     adapter = MinioAdapter()
-    assert not adapter.is_connected
+    assert not adapter.is_connected()
 
 
 def test_should_log_info_when_already_connected(
@@ -137,7 +137,7 @@ def test_should_raise_connection_error_when_unable_to_connect(
     adapter = MinioAdapter()
     with pytest.raises(ConnectionError):
         adapter.connect()
-    assert not adapter.is_connected
+    assert not adapter.is_connected()
 
 
 def test_should_log_info_when_creating_expected_bucket(
@@ -163,7 +163,7 @@ def test_should_log_error_on_exception_during_exit(
     """Test that the MinioAdapter logs an error if an exception occurs during __exit__."""
     try:
         with MinioAdapter() as adapter:
-            assert adapter.is_connected
+            assert adapter.is_connected()
             raise ValueError("Simulated error")
     except ValueError:
         pass  # Expected

tests/integration/redis_adapter_test.py

@@ -9,7 +9,7 @@ from python_repositories.interfaces import JsonRepositoryInterface
 
 
 @pytest.fixture(scope="module")
-def data() -> Generator[dict[str, str]]:
+def data() -> Generator[dict[str, str], None, None]:
     """Provide a sample data dictionary for tests."""
     yield {"foo": "bar"}
 
@@ -18,7 +18,7 @@ def data() -> Generator[dict[str, str]]:
 def data_in_redis(
     raw_redis_client: redis.Redis,
     data: dict[str, str],
-) -> Generator[tuple[str, dict[str, str]]]:
+) -> Generator[tuple[str, dict[str, str]], None, None]:
     """Fixture to set up a known value in Redis before each test."""
     key = "test_key"
     path = RedisPath.root_path()
@@ -31,7 +31,7 @@ def data_in_redis(
 
 
 @pytest.fixture(scope="module")
-def redis_adapter(redis_container: str) -> Generator[RedisAdapter]:
+def redis_adapter(redis_container: str) -> Generator[RedisAdapter, None, None]:
     """Fixture to provide a connected RedisAdapter instance."""
     adapter = RedisAdapter()
     adapter.connect()
@@ -63,7 +63,7 @@ def test_should_not_be_connected_when_instantiated(redis_container: str) -> None
     """Test that the RedisAdapter is not connected when instantiated."""
     adapter = RedisAdapter()
     assert adapter._client is None
-    assert not adapter.is_connected
+    assert not adapter.is_connected()
 
 
 def test_should_raise_connection_error_when_unable_to_connect(
@@ -77,7 +77,7 @@ def test_should_raise_connection_error_when_unable_to_connect(
     with pytest.raises(ConnectionError):
         adapter.connect()
     assert adapter._client is None
-    assert not adapter.is_connected
+    assert not adapter.is_connected()
 
 
 def test_connect_raises_connection_error_when_unable_to_ping(
@@ -109,7 +109,7 @@ def test_should_log_error_on_exception_during_exit(
     """Test that the RedisAdapter logs an error when an exception occurs during context exit."""
     try:
         with RedisAdapter() as adapter:
-            assert adapter.is_connected
+            assert adapter.is_connected()
             raise ValueError("Simulated error")
     except ValueError:
         pass  # Expected

tests/unit/connection_health_test.py

@@ -0,0 +1,184 @@
+"""Tests for TTL-cached connection health checks on adapters."""
+
+from __future__ import annotations
+
+from unittest.mock import MagicMock, patch
+
+import pytest
+import redis
+
+from python_repositories.adapters.minio_adapter import MinioAdapter
+from python_repositories.adapters.redis_adapter import RedisAdapter
+
+
+@pytest.fixture
+def redis_adapter(monkeypatch: pytest.MonkeyPatch) -> RedisAdapter:
+    monkeypatch.setenv("REDIS_URI", "redis://localhost:6379")
+    return RedisAdapter()
+
+
+@pytest.fixture
+def minio_adapter(monkeypatch: pytest.MonkeyPatch) -> MinioAdapter:
+    monkeypatch.setenv("MINIO_ENDPOINT", "localhost:9000")
+    monkeypatch.setenv("MINIO_ACCESS_KEY", "minioadmin")
+    monkeypatch.setenv("MINIO_SECRET_KEY", "minioadmin")
+    monkeypatch.setenv("MINIO_BUCKET", "test-bucket")
+    return MinioAdapter()
+
+
+class TestRedisConnectionHealth:
+    def test_not_connected_when_no_client(self, redis_adapter: RedisAdapter) -> None:
+        assert not redis_adapter.is_connected()
+
+    def test_connected_when_probe_succeeds(self, redis_adapter: RedisAdapter) -> None:
+        mock_client = MagicMock(spec=redis.Redis)
+        mock_client.ping.return_value = True
+        redis_adapter._client = mock_client
+
+        assert redis_adapter.is_connected()
+        mock_client.ping.assert_called_once()
+
+    def test_stale_connection_when_probe_fails(
+        self, redis_adapter: RedisAdapter
+    ) -> None:
+        mock_client = MagicMock(spec=redis.Redis)
+        mock_client.ping.side_effect = redis.ConnectionError("connection lost")
+        redis_adapter._client = mock_client
+
+        assert not redis_adapter.is_connected()
+
+    def test_cache_hit_avoids_second_probe(self, redis_adapter: RedisAdapter) -> None:
+        mock_client = MagicMock(spec=redis.Redis)
+        mock_client.ping.return_value = True
+        redis_adapter._client = mock_client
+
+        with patch(
+            "python_repositories.adapters.redis_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert redis_adapter.is_connected()
+            assert redis_adapter.is_connected()
+
+        mock_client.ping.assert_called_once()
+
+    def test_cache_miss_runs_probe_again(self, redis_adapter: RedisAdapter) -> None:
+        mock_client = MagicMock(spec=redis.Redis)
+        mock_client.ping.return_value = True
+        redis_adapter._client = mock_client
+
+        with patch(
+            "python_repositories.adapters.redis_adapter.time.monotonic",
+            side_effect=[100.0, 102.0],
+        ):
+            assert redis_adapter.is_connected()
+            assert redis_adapter.is_connected()
+
+        assert mock_client.ping.call_count == 2
+
+    def test_disconnect_clears_cache(self, redis_adapter: RedisAdapter) -> None:
+        mock_client = MagicMock(spec=redis.Redis)
+        mock_client.ping.return_value = True
+        redis_adapter._client = mock_client
+
+        with patch(
+            "python_repositories.adapters.redis_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert redis_adapter.is_connected()
+
+        redis_adapter.disconnect()
+        redis_adapter._client = mock_client
+
+        with patch(
+            "python_repositories.adapters.redis_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert redis_adapter.is_connected()
+
+        assert mock_client.ping.call_count == 2
+
+
+class TestMinioConnectionHealth:
+    def test_not_connected_when_no_client(self, minio_adapter: MinioAdapter) -> None:
+        assert not minio_adapter.is_connected()
+
+    def test_not_connected_when_bucket_name_missing(
+        self, minio_adapter: MinioAdapter
+    ) -> None:
+        minio_adapter._client = MagicMock()
+        minio_adapter._bucket_name = None
+
+        assert not minio_adapter.is_connected()
+
+    def test_connected_when_probe_succeeds(self, minio_adapter: MinioAdapter) -> None:
+        mock_client = MagicMock()
+        mock_client.bucket_exists.return_value = True
+        minio_adapter._client = mock_client
+        minio_adapter._bucket_name = "test-bucket"
+
+        assert minio_adapter.is_connected()
+        mock_client.bucket_exists.assert_called_once_with("test-bucket")
+
+    def test_stale_connection_when_probe_fails(
+        self, minio_adapter: MinioAdapter
+    ) -> None:
+        mock_client = MagicMock()
+        mock_client.bucket_exists.side_effect = Exception("connection lost")
+        minio_adapter._client = mock_client
+        minio_adapter._bucket_name = "test-bucket"
+
+        assert not minio_adapter.is_connected()
+
+    def test_cache_hit_avoids_second_probe(self, minio_adapter: MinioAdapter) -> None:
+        mock_client = MagicMock()
+        mock_client.bucket_exists.return_value = True
+        minio_adapter._client = mock_client
+        minio_adapter._bucket_name = "test-bucket"
+
+        with patch(
+            "python_repositories.adapters.minio_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert minio_adapter.is_connected()
+            assert minio_adapter.is_connected()
+
+        mock_client.bucket_exists.assert_called_once()
+
+    def test_cache_miss_runs_probe_again(self, minio_adapter: MinioAdapter) -> None:
+        mock_client = MagicMock()
+        mock_client.bucket_exists.return_value = True
+        minio_adapter._client = mock_client
+        minio_adapter._bucket_name = "test-bucket"
+
+        with patch(
+            "python_repositories.adapters.minio_adapter.time.monotonic",
+            side_effect=[100.0, 102.0],
+        ):
+            assert minio_adapter.is_connected()
+            assert minio_adapter.is_connected()
+
+        assert mock_client.bucket_exists.call_count == 2
+
+    def test_disconnect_clears_cache(self, minio_adapter: MinioAdapter) -> None:
+        mock_client = MagicMock()
+        mock_client.bucket_exists.return_value = True
+        minio_adapter._client = mock_client
+        minio_adapter._bucket_name = "test-bucket"
+
+        with patch(
+            "python_repositories.adapters.minio_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert minio_adapter.is_connected()
+
+        minio_adapter.disconnect()
+        minio_adapter._client = mock_client
+        minio_adapter._bucket_name = "test-bucket"
+
+        with patch(
+            "python_repositories.adapters.minio_adapter.time.monotonic",
+            return_value=100.0,
+        ):
+            assert minio_adapter.is_connected()
+
+        assert mock_client.bucket_exists.call_count == 2