generic conn pool: directly use thread local cluster

test/extensions/upstreams/tcp/generic/BUILD

@@ -0,0 +1,18 @@
+load(
+    "//bazel:envoy_build_system.bzl",
+    "envoy_cc_test",
+    "envoy_package",
+)
+
+licenses(["notice"])  # Apache 2
+
+envoy_package()
+
+envoy_cc_test(
+    name = "config_test",
+    srcs = ["config_test.cc"],
+    deps = [
+        "//source/extensions/upstreams/tcp/generic:config",
+        "//test/mocks/upstream:upstream_mocks",
+    ],
+)

test/extensions/upstreams/tcp/generic/config_test.cc

@@ -0,0 +1,38 @@
+#include "extensions/upstreams/tcp/generic/config.h"
+
+#include "test/mocks/tcp/mocks.h"
+#include "test/mocks/upstream/cluster_manager.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+using testing::_;
+using testing::NiceMock;
+using testing::Return;
+
+namespace Envoy {
+namespace Extensions {
+namespace Upstreams {
+namespace Tcp {
+namespace Generic {
+
+class TcpConnPoolTest : public ::testing::Test {
+public:
+  NiceMock<Upstream::MockThreadLocalCluster> thread_local_cluster_;
+  GenericConnPoolFactory factory_;
+  NiceMock<Envoy::Tcp::ConnectionPool::MockUpstreamCallbacks> callbacks_;
+};
+
+TEST_F(TcpConnPoolTest, TestNoHost) {
+  envoy::extensions::filters::network::tcp_proxy::v3::TcpProxy_TunnelingConfig config;
+  config.set_hostname("host");
+  EXPECT_CALL(thread_local_cluster_, httpConnPool(_, _, _)).WillOnce(Return(nullptr));
+  EXPECT_EQ(nullptr,
+            factory_.createGenericConnPool(thread_local_cluster_, config, nullptr, callbacks_));
+}
+
+} // namespace Generic
+} // namespace Tcp
+} // namespace Upstreams
+} // namespace Extensions
+} // namespace Envoy