fix: make channel cache

tests/test_channel_cache.py

@@ -0,0 +1,90 @@
+from unittest.mock import patch
+
+import grpc
+import pytest
+
+from yandexcloud import SDK
+from yandexcloud._channels import Channels
+
+ENDPOINTS = {
+    "iam": "iam.api.cloud.yandex.net:443",
+    "compute": "compute.api.cloud.yandex.net:443",
+    "vpc": "vpc.api.cloud.yandex.net:443",
+}
+
+
+@pytest.fixture
+def mock_channels():
+    with patch.multiple(
+        Channels,
+        _get_creds=lambda self, endpoint: grpc.local_channel_credentials(),
+        _get_endpoints=lambda self: dict(ENDPOINTS),
+    ):
+        yield
+
+
+class TestChannelCache:
+    def test_same_service_returns_same_channel(self, mock_channels):
+        sdk = SDK()
+        channels = sdk._channels
+
+        ch1 = channels.channel("compute")
+        ch2 = channels.channel("compute")
+
+        assert ch1 is ch2
+
+    def test_different_services_return_different_channels(self, mock_channels):
+        sdk = SDK()
+        channels = sdk._channels
+
+        ch_compute = channels.channel("compute")
+        ch_vpc = channels.channel("vpc")
+
+        assert ch_compute is not ch_vpc
+
+    def test_same_service_with_explicit_endpoint_returns_same_channel(self, mock_channels):
+        sdk = SDK()
+        channels = sdk._channels
+
+        ch1 = channels.channel("compute", endpoint="custom:443")
+        ch2 = channels.channel("compute", endpoint="custom:443")
+
+        assert ch1 is ch2
+
+    def test_different_endpoints_return_different_channels(self, mock_channels):
+        sdk = SDK()
+        channels = sdk._channels
+
+        ch1 = channels.channel("compute", endpoint="host1:443")
+        ch2 = channels.channel("compute", endpoint="host2:443")
+
+        assert ch1 is not ch2
+
+    def test_insecure_and_secure_return_different_channels(self, mock_channels):
+        sdk = SDK(endpoints={"compute": "localhost:50051"})
+        channels = sdk._channels
+
+        ch_secure = channels.channel("compute", insecure=False)
+        ch_insecure = channels.channel("compute", insecure=True)
+
+        assert ch_secure is not ch_insecure
+
+    def test_repeated_calls_do_not_grow_channel_count(self, mock_channels):
+        sdk = SDK()
+        channels = sdk._channels
+
+        for _ in range(100):
+            channels.channel("compute")
+            channels.channel("vpc")
+
+        assert len(channels._channels) == 2
+
+    def test_default_endpoint_cached_separately_from_explicit(self, mock_channels):
+        sdk = SDK()
+        channels = sdk._channels
+
+        ch_default = channels.channel("compute")
+        ch_explicit = channels.channel("compute", endpoint="custom:443")
+
+        assert ch_default is not ch_explicit
+        assert len(channels._channels) == 2