Allow tcp_client::init to fail correctly

sentinel_2pc::controller::init contains a bug that makes it impossible to
trigger the error "Failed to start coordinator client" (see GitHub Issue mit-dci#131).
This commit fixes the bug using the method described in Issue mit-dci#131.  It
adds a new unit test to test triggering the error, and also modifies a
different unit test to account for behavior that's expected after the bug fix.

Signed-off-by: Michael L. Szulczewski <[email protected]>

src/util/rpc/tcp_client.hpp

@@ -55,7 +55,7 @@ namespace cbdc::rpc {
         /// starts the response handler thread.
         /// \return true.
         [[nodiscard]] auto init() -> bool {
-            if(!m_net.cluster_connect(m_server_endpoints, false)) {
+            if(!m_net.cluster_connect(m_server_endpoints, true)) {
                 return false;
             }
 

tests/unit/rpc/tcp_test.cpp

@@ -126,7 +126,7 @@ TEST(tcp_rpc_test, send_fail_test) {
     auto client = cbdc::rpc::tcp_client<request, response>(
         {{cbdc::network::localhost, 55555},
          {cbdc::network::localhost, 55556}});
-    ASSERT_TRUE(client.init());
+    ASSERT_FALSE(client.init());
 
     auto req = request{0};
     auto resp = client.call(req);

tests/unit/sentinel_2pc/controller_test.cpp

@@ -169,3 +169,60 @@ TEST_F(sentinel_2pc_test, tx_validation_test) {
           });
     ASSERT_TRUE(res);
 }
+
+TEST_F(sentinel_2pc_test, bad_coordinator_endpoint) {
+    // Replace the valid coordinator endpoint defined in the fixture
+    // with an invalid endpoint.
+    m_opts.m_coordinator_endpoints.clear();
+    const auto bad_coordinator_ep
+        = std::make_pair("abcdefg", m_coordinator_port);
+    m_opts.m_coordinator_endpoints.resize(1);
+    m_opts.m_coordinator_endpoints[0].push_back(bad_coordinator_ep);
+
+    // Initialize a new controller with the invalid coordinator endpoint.
+    auto ctl = std::make_unique<cbdc::sentinel_2pc::controller>(0,
+                                                                m_opts,
+                                                                m_logger);
+
+    // Check that the controller with the invalid coordinator endpoint
+    // fails to initialize correctly.
+    ASSERT_FALSE(ctl->init());
+}
+
+TEST_F(sentinel_2pc_test, bad_sentinel_client_endpoint) {
+    // Test that a sentinel client fails to initialize
+    // when given a bad endpoint.
+    constexpr auto bad_endpoint = std::make_pair("abcdefg", m_sentinel_port);
+    const std::vector<cbdc::network::endpoint_t> bad_endpoints{bad_endpoint};
+    auto client = cbdc::sentinel::rpc::client(bad_endpoints, m_logger);
+    ASSERT_FALSE(client.init());
+
+    // Test that the controller fails to initialize when given a bad endpoint
+    // for a sentinel client.
+    m_opts.m_sentinel_endpoints.emplace_back(bad_endpoint);
+    auto ctl = std::make_unique<cbdc::sentinel_2pc::controller>(0,
+                                                                m_opts,
+                                                                m_logger);
+    ASSERT_FALSE(ctl->init());
+}
+
+TEST_F(sentinel_2pc_test, bad_rpc_server_endpoint) {
+    // The sentinel endpoint defined below (which corresponds to sentinel_id
+    // also defined below) is used by the sentinel_2pc controller to initialize
+    // an rpc server.  Replacing the valid endpoint defined in the fixture with
+    // an invalid endpoint should cause the rpc server to fail to initialize.
+    m_opts.m_sentinel_endpoints.clear();
+    constexpr auto bad_endpoint = std::make_pair("abcdefg", m_sentinel_port);
+    m_opts.m_sentinel_endpoints.resize(1);
+    m_opts.m_sentinel_endpoints.emplace_back(bad_endpoint);
+
+    // Initialize a new controller with the invalid endpoint for the server.
+    constexpr uint32_t sentinel_id = 0;
+    const auto ctl
+        = std::make_unique<cbdc::sentinel_2pc::controller>(sentinel_id,
+                                                           m_opts,
+                                                           m_logger);
+
+    // Check that the controller with the invalid endpoint fails to initialize.
+    ASSERT_FALSE(ctl->init());
+}