ILogStuff - enabling logging from `connection_impl` and transports

Note that a side effect of this change is that we now will be able to raise events from transports since transports now will have a (smart) pointer to the connection_impl instance.

include/signalrclient/connection.h

@@ -7,6 +7,9 @@
 #include "_exports.h"
 #include "transport_type.h"
 #include "connection_state.h"
+#include "trace_level.h"
+#include "log_writer.h"
+#include "trace_log_writer.h"
 
 namespace signalr
 {
@@ -15,7 +18,8 @@ namespace signalr
     class connection
     {
     public:
-        explicit connection(const utility::string_t& url, const utility::string_t& querystring = U(""));
+        explicit connection(const utility::string_t& url, const utility::string_t& querystring = U(""), 
+            trace_level trace_level = trace_level::all, std::shared_ptr<log_writer> log_writer = std::make_shared<trace_log_writer>());
 
         // TODO: consider making connection class copyable to enable passing by value
         connection(const connection&) = delete;

src/signalrclient/connection.cpp

@@ -8,8 +8,8 @@
 
 namespace signalr
 {
-    connection::connection(const utility::string_t& url, const utility::string_t& querystring)
+    connection::connection(const utility::string_t& url, const utility::string_t& querystring, trace_level trace_level, std::shared_ptr<log_writer> log_writer)
-        : m_pImpl(connection_impl::create(url, querystring))
+        : m_pImpl(connection_impl::create(url, querystring, trace_level, log_writer))
     {}
 
     // Do NOT remove this destructor. Letting the compiler generate and inline the default dtor may lead to

src/signalrclient/connection_impl.cpp

@@ -8,20 +8,21 @@
 
 namespace signalr
 {
-    std::shared_ptr<connection_impl> connection_impl::create(const utility::string_t& url, const utility::string_t& querystring)
-    {
-        return connection_impl::create(url, querystring, std::make_unique<web_request_factory>(), std::make_unique<transport_factory>());
-    }
-
     std::shared_ptr<connection_impl> connection_impl::create(const utility::string_t& url, const utility::string_t& querystring, 
-        std::unique_ptr<web_request_factory> web_request_factory, std::unique_ptr<transport_factory> transport_factory)
+        trace_level trace_level, std::shared_ptr<log_writer> log_writer)
     {
-        return std::shared_ptr<connection_impl>(new connection_impl(url, querystring, std::move(web_request_factory), std::move(transport_factory)));
+        return connection_impl::create(url, querystring, trace_level, log_writer, std::make_unique<web_request_factory>(), std::make_unique<transport_factory>());
     }
 
-    connection_impl::connection_impl(const utility::string_t& url, const utility::string_t& querystring,
+    std::shared_ptr<connection_impl> connection_impl::create(const utility::string_t& url, const utility::string_t& querystring, trace_level trace_level, 
+        std::shared_ptr<log_writer> log_writer, std::unique_ptr<web_request_factory> web_request_factory, std::unique_ptr<transport_factory> transport_factory)
+    {
+        return std::shared_ptr<connection_impl>(new connection_impl(url, querystring, trace_level, log_writer, std::move(web_request_factory), std::move(transport_factory)));
+    }
+
+    connection_impl::connection_impl(const utility::string_t& url, const utility::string_t& querystring, trace_level trace_level, std::shared_ptr<log_writer> log_writer,
         std::unique_ptr<web_request_factory> web_request_factory, std::unique_ptr<transport_factory> transport_factory)
-        : m_base_uri(url), m_querystring(querystring), m_web_request_factory(std::move(web_request_factory)), 
+        : m_base_uri(url), m_querystring(querystring), m_logger(log_writer, trace_level), m_web_request_factory(std::move(web_request_factory)), 
         m_transport_factory(std::move(transport_factory)), m_connection_state(std::move(connection_state::disconnected))
     { }
 
@@ -41,17 +42,47 @@ namespace signalr
         return m_connection_state.load();
     }
 
+    logger connection_impl::get_logger() const
+    {
+        return m_logger;
+    }
+
     bool connection_impl::change_state(connection_state old_state, connection_state new_state)
     {
         connection_state expected_state{ old_state };
 
-        if (!m_connection_state.compare_exchange_strong(expected_state, new_state, std::memory_order_seq_cst))
+        if (m_connection_state.compare_exchange_strong(expected_state, new_state, std::memory_order_seq_cst))
         {
-            // TODO: add logging
+            m_logger.log(
+                trace_level::state_changes,
+                utility::string_t(_XPLATSTR("state changed: "))
+                .append(translate_connection_state(old_state))
+                .append(_XPLATSTR(" -> "))
+                .append(translate_connection_state(new_state)));
+
             // TODO: invoke state_changed callback
-            return false;
+
+            return true;
         }
 
-        return true;
+        return false;
+    }
+
+    utility::string_t connection_impl::translate_connection_state(connection_state state)
+    {
+        switch (state)
+        {
+        case connection_state::connecting:
+            return _XPLATSTR("connecting");
+        case connection_state::connected:
+            return _XPLATSTR("connected");
+        case connection_state::reconnecting:
+            return _XPLATSTR("reconnecting");
+        case connection_state::disconnected:
+            return _XPLATSTR("disconnected");
+        default:
+            _ASSERTE(false);
+            return _XPLATSTR("(unknown)");
+        }
     }
 }

src/signalrclient/connection_impl.h

@@ -21,10 +21,11 @@ namespace signalr
     class connection_impl : public std::enable_shared_from_this<connection_impl>
     {
     public:
-        static std::shared_ptr<connection_impl> create(const utility::string_t& url, const utility::string_t& querystring);
-
         static std::shared_ptr<connection_impl> create(const utility::string_t& url, const utility::string_t& querystring, 
-            std::unique_ptr<web_request_factory> web_request_factory, std::unique_ptr<transport_factory> transport_factory);
+            trace_level trace_level, std::shared_ptr<log_writer> log_writer);
+
+        static std::shared_ptr<connection_impl> create(const utility::string_t& url, const utility::string_t& querystring, trace_level trace_level, 
+            std::shared_ptr<log_writer> log_writer, std::unique_ptr<web_request_factory> web_request_factory, std::unique_ptr<transport_factory> transport_factory);
 
         connection_impl(const connection_impl&) = delete;
 
@@ -34,17 +35,21 @@ namespace signalr
 
         connection_state get_connection_state() const;
 
+        logger get_logger() const;
+
     private:
         web::uri m_base_uri;
         utility::string_t m_querystring;
         std::atomic<connection_state> m_connection_state;
+        logger m_logger;
 
         std::unique_ptr<web_request_factory> m_web_request_factory;
         std::unique_ptr<transport_factory> m_transport_factory;
 
-        connection_impl(const utility::string_t& url, const utility::string_t& querystring,
+        connection_impl(const utility::string_t& url, const utility::string_t& querystring, trace_level trace_level, std::shared_ptr<log_writer> log_writer,
             std::unique_ptr<web_request_factory> web_request_factory, std::unique_ptr<transport_factory> transport_factory);
 
         bool change_state(connection_state old_state, connection_state new_state);
+        utility::string_t translate_connection_state(connection_state state);
     };
 }

src/signalrclient/logger.cpp

@@ -16,9 +16,21 @@ namespace signalr
     {
         if ((level & m_trace_level) != trace_level::none)
         {
-            utility::ostringstream_t os;
+            try
-            os << utility::datetime::utc_now().to_string(utility::datetime::date_format::ISO_8601) << _XPLATSTR(" ") << entry << std::endl;
+            {
-            m_log_writer->write(os.str());
+                utility::ostringstream_t os;
+                os << utility::datetime::utc_now().to_string(utility::datetime::date_format::ISO_8601) << _XPLATSTR(" ") << entry << std::endl;
+                m_log_writer->write(os.str());
+            }
+            catch (const std::exception &e)
+            {
+                ucerr << _XPLATSTR("error occurred when logging: ") << utility::conversions::to_string_t(e.what()) 
+                    << std::endl << _XPLATSTR("    entry: ") << entry << std::endl;
+            }
+            catch (...)
+            {
+                ucerr << _XPLATSTR("unknown error occurred when logging") << std::endl << _XPLATSTR("    entry: ") << entry << std::endl;
+            }
         }
     }
 }

src/signalrclient/transport_factory.cpp

@@ -4,14 +4,15 @@
 #include "stdafx.h"
 #include "transport_factory.h"
 #include "websocket_transport.h"
+#include "connection_impl.h"
 
 namespace signalr
 {
-    std::unique_ptr<transport> transport_factory::create_transport(transport_type transport_type)
+    std::unique_ptr<transport> transport_factory::create_transport(transport_type transport_type, std::shared_ptr<connection_impl> connection)
     {
         if (transport_type == transport_type::websockets)
         {
-            return std::make_unique<websocket_transport>(std::make_unique<default_websocket_client>());
+            return std::make_unique<websocket_transport>(std::make_unique<default_websocket_client>(), connection);
         }
 
         throw std::exception("not implemented");

src/signalrclient/transport_factory.h

@@ -9,10 +9,12 @@
 
 namespace signalr
 {
+    class connection_impl;
+
     class transport_factory
     {
     public:
-        std::unique_ptr<transport> virtual create_transport(transport_type transport_type);
+        virtual std::unique_ptr<transport> create_transport(transport_type transport_type, std::shared_ptr<connection_impl> connection);
 
         virtual ~transport_factory();
     };

src/signalrclient/websocket_transport.cpp

@@ -3,16 +3,17 @@
 
 #include "stdafx.h"
 #include "websocket_transport.h"
+#include "logger.h"
 
 namespace signalr
 {
     namespace
     {
-        void receive_loop(std::shared_ptr<websocket_client> websocket_client, pplx::cancellation_token_source cts);
+        void receive_loop(std::shared_ptr<websocket_client> websocket_client, std::shared_ptr<connection_impl> connection, pplx::cancellation_token_source cts);
     }
 
-    websocket_transport::websocket_transport(std::shared_ptr<websocket_client> websocket_client)
+    websocket_transport::websocket_transport(std::shared_ptr<websocket_client> websocket_client, std::shared_ptr<connection_impl> connection)
-        : m_websocket_client(websocket_client)
+        : m_websocket_client(websocket_client), m_connection(connection)
     {
         // we use this cts to check if the receive loop is running so it should be 
         // initially cancelled to indicate that the receive loop is not running
@@ -41,21 +42,27 @@ namespace signalr
         pplx::cancellation_token_source receive_loop_cts;
         std::shared_ptr<websocket_client> websocket_client(m_websocket_client);
         pplx::task_completion_event<void> connect_tce;
+        auto connection = m_connection;
 
         m_websocket_client->connect(url)
-            .then([websocket_client, connect_tce, receive_loop_cts](pplx::task<void> connect_task)
+            .then([websocket_client, connect_tce, receive_loop_cts, connection](pplx::task<void> connect_task)
         {
             try
             {
                 connect_task.get();
-                receive_loop(websocket_client, receive_loop_cts);
+                receive_loop(websocket_client, connection, receive_loop_cts);
                 connect_tce.set();
             }
             catch (const std::exception &e)
             {
-                // TODO: logging, on error(?) - see what we do in the .net client
+                connection->get_logger().log(
+                    trace_level::messages,
+                    utility::string_t(_XPLATSTR("[websocket transport] exception when connecting to the server: "))
+                        .append(utility::conversions::to_string_t(e.what())));
+
+                // TODO: on error(?) - see what we do in the .net client
                 receive_loop_cts.cancel();
-                connect_tce.set_exception(e);
+                connect_tce.set_exception(std::current_exception());
             }
         });
 
@@ -74,27 +81,36 @@ namespace signalr
     {
         m_receive_loop_cts.cancel();
 
+        auto logger = m_connection->get_logger();
+
         return m_websocket_client->close()
-            .then([](pplx::task<void> close_task)
+            .then([logger](pplx::task<void> close_task)
-            {
+            mutable {
                 try
                 {
                     close_task.get();
                 }
-                catch (const std::exception &)
+                catch (const std::exception &e)
                 {
-                    // TODO:log
+                    logger.log(
+                        trace_level::messages,
+                        utility::string_t(_XPLATSTR("[websocket transport] exception when closing websocket: "))
+                        .append(utility::conversions::to_string_t(e.what())));
                 }
             });
     }
 
-    // unnamed namespace makes this function invisible for other translation units 
+    // unnamed namespace makes this function invisible/unusable in other translation units 
     namespace
     {
-        void receive_loop(std::shared_ptr<websocket_client> websocket_client, pplx::cancellation_token_source cts)
+        void receive_loop(std::shared_ptr<websocket_client> websocket_client, std::shared_ptr<connection_impl> connection, pplx::cancellation_token_source cts)
         {
             websocket_client->receive()
-                .then([websocket_client, cts](pplx::task<std::string> receive_task)
+                // There are two cases when we exit the loop. The first case is implicit - we pass the cancellation_token
+                // to `then` (note this is after the lambda body) and if the token is cancelled the continuation will not
+                // run at all. The second - explicit - case happens if the token gets cancelled after the continuation has
+                // been started in which case we just stop the loop by not scheduling another receive task.
+                .then([websocket_client, connection, cts](pplx::task<std::string> receive_task)
             {
                 try
                 {
@@ -104,29 +120,41 @@ namespace signalr
 
                     if (!pplx::is_task_cancellation_requested())
                     {
-                        receive_loop(websocket_client, cts);
+                        receive_loop(websocket_client, connection, cts);
                     }
 
-                    // TODO: `else` to log that loop has been cancelled?
-
                     return;
                 }
-                // TODO: log, report error, close websocket (when appropriate)
+                // TODO: report error, close websocket (when appropriate)
-                catch (const web_sockets::client::websocket_exception&)
+                catch (const web_sockets::client::websocket_exception& e)
                 {
+                    connection->get_logger().log(
+                        trace_level::messages,
+                        utility::string_t(_XPLATSTR("[websocket transport] websocket exception when receiving data: "))
+                        .append(utility::conversions::to_string_t(e.what())));
                 }
-                catch (const pplx::task_canceled &)
+                catch (const pplx::task_canceled& e)
                 {
+                    connection->get_logger().log(
+                        trace_level::messages,
+                        utility::string_t(_XPLATSTR("[websocket transport] receive task cancelled: "))
+                        .append(utility::conversions::to_string_t(e.what())));
                 }
-                catch (const std::exception&)
+                catch (const std::exception& e)
                 {
+                    connection->get_logger().log(
+                        trace_level::messages,
+                        utility::string_t(_XPLATSTR("[websocket transport] error receiving response from websocket: "))
+                        .append(utility::conversions::to_string_t(e.what())));
                 }
                 catch (...)
                 {
+                    connection->get_logger().log(
+                        trace_level::messages,
+                        utility::string_t(_XPLATSTR("[websocket transport] unknown error occurred when receiving response from websocket")));
                 }
 
                 cts.cancel();
-
             }, cts.get_token());
         }
     }

src/signalrclient/websocket_transport.h

@@ -8,14 +8,14 @@
 #include "transport.h"
 #include "logger.h"
 #include "default_websocket_client.h"
+#include "connection_impl.h"
 
 namespace signalr
 {
     class websocket_transport : public transport
     {
     public:
-
+        websocket_transport(std::shared_ptr<websocket_client> websocket_client, std::shared_ptr<connection_impl> connection);
-        websocket_transport(std::shared_ptr<websocket_client> websocket_client);
 
         ~websocket_transport();
 
@@ -31,6 +31,7 @@ namespace signalr
 
     private:
         std::shared_ptr<websocket_client> m_websocket_client;
+        std::shared_ptr<connection_impl> m_connection;
 
         pplx::cancellation_token_source m_receive_loop_cts;
     };

test/signalrclienttests/Build/VS2013/signalrclienttests.vcxproj

@@ -88,6 +88,7 @@
     <ClInclude Include="..\..\memory_log_writer.h" />
     <ClInclude Include="..\..\stdafx.h" />
     <ClInclude Include="..\..\targetver.h" />
+    <ClInclude Include="..\..\test_utils.h" />
     <ClInclude Include="..\..\test_websocket_client.h" />
     <ClInclude Include="..\..\test_web_request_factory.h" />
     <ClInclude Include="..\..\web_request_stub.h" />
@@ -103,6 +104,7 @@
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">Create</PrecompiledHeader>
       <PrecompiledHeader Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">Create</PrecompiledHeader>
     </ClCompile>
+    <ClCompile Include="..\..\test_utils.cpp" />
     <ClCompile Include="..\..\test_websocket_client.cpp" />
     <ClCompile Include="..\..\test_web_request_factory.cpp" />
     <ClCompile Include="..\..\url_builder_tests.cpp" />

test/signalrclienttests/Build/VS2013/signalrclienttests.vcxproj.filters

@@ -33,6 +33,9 @@
     <ClInclude Include="..\..\memory_log_writer.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\test_utils.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\stdafx.cpp">
@@ -74,6 +77,9 @@
     <ClCompile Include="..\..\memory_log_writer.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\test_utils.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />

test/signalrclienttests/connection_impl_tests.cpp

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 #include "stdafx.h"
+#include "test_utils.h"
 #include "connection_impl.h"
 #include "signalrclient\trace_level.h"
 #include "signalrclient\trace_log_writer.h"
@@ -13,14 +14,17 @@ using namespace signalr;
 
 TEST(connection_impl_connection_state, initial_connection_state_is_disconnected)
 {
-    auto connection = connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""));
+    auto connection = 
+        connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>());
 
     ASSERT_EQ(connection_state::disconnected, connection->get_connection_state());
 }
 
 TEST(connection_impl_start, cannot_start_non_disconnected_exception)
 {
-    auto connection = connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""));
+    auto connection = 
+        connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>());
+
     connection->start().wait();
 
     try
@@ -32,14 +36,31 @@ TEST(connection_impl_start, cannot_start_non_disconnected_exception)
     {
         ASSERT_EQ(
             _XPLATSTR("cannot start a connection that is not in the disconnected state"),
-            utility::conversions::print_string(e.what()));
+            utility::conversions::to_string_t(e.what()));
     }
 }
 
 TEST(connection_impl_start, connection_state_is_connecting_when_connection_is_being_started)
 {
-    auto connection = connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""));
+    auto connection = 
+        connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>());
 
     connection->start().wait();
     ASSERT_EQ(connection->get_connection_state(), connection_state::connecting);
 }
+
+TEST(connection_impl_change_state, change_state_logs)
+{
+    std::shared_ptr<log_writer> writer(std::make_shared<memory_log_writer>());
+
+    auto connection = 
+        connection_impl::create(_XPLATSTR("url"), _XPLATSTR(""), trace_level::state_changes, writer);
+
+    connection->start().wait();
+
+    auto log_entries = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries();
+    ASSERT_FALSE(log_entries.empty());
+
+    auto entry = remove_date_from_log_entry(log_entries[0]);
+    ASSERT_EQ(_XPLATSTR("state changed: disconnected -> connecting\n"), entry);
+}

test/signalrclienttests/http_sender_tests.cpp

@@ -31,7 +31,7 @@ TEST(http_sender_get_response, exception_thrown_if_status_code_not_200)
     {
         ASSERT_EQ(
             _XPLATSTR("web exception: 404 ") + response_phrase,
-            utility::conversions::print_string(e.what()));
+            utility::conversions::to_string_t(e.what()));
     }
 }
 

test/signalrclienttests/logger_tests.cpp

@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 #include "stdafx.h"
+#include "test_utils.h"
 #include <cpprest\asyncrt_utils.h>
 #include "signalrclient\trace_log_writer.h"
 #include "logger.h"
@@ -29,7 +30,7 @@ TEST(logger_write, entry_not_added_if_trace_level_not_set)
 
     auto log_entries = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries();
 
-    ASSERT_EQ(0, log_entries.size());
+    ASSERT_TRUE(log_entries.empty());
 }
 
 TEST(logger_write, entries_added_for_combined_trace_level)
@@ -53,11 +54,14 @@ TEST(logger_write, entries_formatted_correctly)
     logger l(writer, trace_level::all);
     l.log(trace_level::messages, _XPLATSTR("message"));
 
-    auto entry = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries()[0];
+    auto log_entries = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries();
+    ASSERT_FALSE(log_entries.empty());
 
-    auto date_str = entry.substr(0, 28);
+    auto entry = log_entries[0];
+
+    auto date_str = entry.substr(0, entry.find_first_of(_XPLATSTR("Z")) + 1);
     auto date = utility::datetime::from_string(date_str, utility::datetime::ISO_8601);
     ASSERT_EQ(date_str, date.to_string(utility::datetime::ISO_8601));
 
-    ASSERT_EQ(_XPLATSTR(" message\n"), entry.substr(28));
+    ASSERT_EQ(_XPLATSTR("message\n"), remove_date_from_log_entry(entry));
 }

test/signalrclienttests/test_utils.cpp

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+#include "stdafx.h"
+#include "cpprest\basic_types.h"
+
+utility::string_t remove_date_from_log_entry(const utility::string_t &log_entry)
+{
+    // dates are ISO 8601 (e.g. `2014-11-13T06:05:29.452066Z`)
+    auto date_end_index = log_entry.find_first_of(_XPLATSTR("Z")) + 1;
+
+    // date is followed by a whitespace hence +1
+    return log_entry.substr(date_end_index + 1);
+}

test/signalrclienttests/test_utils.h

@@ -0,0 +1,8 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+#pragma once
+
+#include <cpprest\basic_types.h>
+
+utility::string_t remove_date_from_log_entry(const utility::string_t &log_entry);

test/signalrclienttests/websocket_transport_tests.cpp

@@ -2,8 +2,11 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 #include "stdafx.h"
+#include "test_utils.h"
+#include "signalrclient\trace_log_writer.h"
 #include "test_websocket_client.h"
 #include "websocket_transport.h"
+#include "memory_log_writer.h"
 
 using namespace signalr;
 using namespace web::experimental;
@@ -26,7 +29,8 @@ TEST(websocket_transport_connect, connect_connects_and_starts_receive_loop)
         return pplx::task_from_result(std::string(""));
     });
 
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"), _XPLATSTR(""),
+        trace_level::none, std::make_shared<trace_log_writer>()) };
 
     ws_transport.connect(_XPLATSTR("http://fakeuri.org")).get();
 
@@ -37,28 +41,61 @@ TEST(websocket_transport_connect, connect_connects_and_starts_receive_loop)
 TEST(websocket_transport_connect, connect_propagates_exceptions)
 {
     auto client = std::make_shared<test_websocket_client>();
-    client->set_connect_function([](const web::uri &) -> pplx::task<void>
+    client->set_connect_function([](const web::uri &)->pplx::task<void>
     {
-        throw web_sockets::client::websocket_exception(_XPLATSTR("connecting failed"));
+        return pplx::task_from_exception<void>(web_sockets::client::websocket_exception(_XPLATSTR("connecting failed")));
     });
 
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
 
     try
     {
-        ws_transport.connect(_XPLATSTR("http://fakeuri.org")).wait();
+        ws_transport.connect(_XPLATSTR("http://fakeuri.org")).get();
         ASSERT_TRUE(false); // exception not thrown
     }
     catch (const std::exception &e)
     {
-        ASSERT_STREQ("connecting failed", e.what());
+        ASSERT_EQ(_XPLATSTR("connecting failed"), utility::conversions::to_string_t(e.what()));
     }
 }
 
+TEST(websocket_transport_connect, connect_logs_exceptions)
+{
+    auto client = std::make_shared<test_websocket_client>();
+    client->set_connect_function([](const web::uri &) -> pplx::task<void>
+    {
+        return pplx::task_from_exception<void>(web_sockets::client::websocket_exception(_XPLATSTR("connecting failed")));
+    });
+
+    std::shared_ptr<log_writer> writer(std::make_shared<memory_log_writer>());
+
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"), 
+        _XPLATSTR(""), trace_level::messages, writer) };
+
+    try
+    {
+        ws_transport.connect(_XPLATSTR("http://fakeuri.org")).wait();
+    }
+    catch (...)
+    { }
+
+    auto log_entries = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries();
+
+    ASSERT_FALSE(log_entries.empty());
+
+    auto entry = remove_date_from_log_entry(log_entries[0]);
+
+    ASSERT_EQ(
+        _XPLATSTR("[websocket transport] exception when connecting to the server: connecting failed\n"),
+        entry);
+}
+
 TEST(websocket_transport_connect, cannot_call_connect_on_already_connected_transport)
 {
     auto client = std::make_shared<test_websocket_client>();
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
 
     ws_transport.connect(_XPLATSTR("http://fakeuri.org")).wait();
 
@@ -69,7 +106,7 @@ TEST(websocket_transport_connect, cannot_call_connect_on_already_connected_trans
     }
     catch (const std::exception &e)
     {
-        ASSERT_STREQ("transport already connected", e.what());
+        ASSERT_EQ(_XPLATSTR("transport already connected"), utility::conversions::to_string_t(e.what()));
     }
 }
 
@@ -77,7 +114,8 @@ TEST(websocket_transport_connect, can_connect_after_disconnecting)
 {
 
     auto client = std::make_shared<test_websocket_client>();
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
 
     ws_transport.connect(_XPLATSTR("http://fakeuri.org")).get();
     ws_transport.disconnect().get();
@@ -97,7 +135,8 @@ TEST(websocket_transport_send, send_creates_and_sends_websocket_messages)
         return pplx::task_from_result();
     });
 
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
 
     ws_transport.send(_XPLATSTR("ABC")).wait();
 
@@ -116,7 +155,8 @@ TEST(websocket_transport_disconnect, disconnect_closes_websocket)
         return pplx::task_from_result();
     });
 
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
 
     ws_transport.disconnect().get();
 
@@ -132,10 +172,42 @@ TEST(websocket_transport_disconnect, disconnect_does_not_throw)
         return pplx::task_from_exception<void>(std::exception());
     });
 
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
     ws_transport.disconnect().get();
 }
 
+TEST(websocket_transport_disconnect, disconnect_logs_exceptions)
+{
+    auto client = std::make_shared<test_websocket_client>();
+    client->set_close_function([]()->pplx::task<void>
+    {
+        return pplx::task_from_exception<void>(web_sockets::client::websocket_exception(_XPLATSTR("connection closing failed")));
+    });
+
+    std::shared_ptr<log_writer> writer(std::make_shared<memory_log_writer>());
+
+    websocket_transport ws_transport{client, connection_impl::create(_XPLATSTR("http://fake.uri"), 
+        _XPLATSTR(""), trace_level::messages, writer)};
+
+    try
+    {
+        ws_transport.disconnect().get();
+    }
+    catch (...) 
+    {}
+
+    auto log_entries = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries();
+
+    ASSERT_FALSE(log_entries.empty());
+
+    auto entry = remove_date_from_log_entry(log_entries[0]);
+
+    ASSERT_EQ(
+        _XPLATSTR("[websocket transport] exception when closing websocket: connection closing failed\n"),
+        entry);
+}
+
 TEST(websocket_transport_disconnect, receive_not_called_after_disconnect)
 {
     auto client = std::make_shared<test_websocket_client>();
@@ -157,7 +229,8 @@ TEST(websocket_transport_disconnect, receive_not_called_after_disconnect)
         return pplx::create_task(receive_task_tce);
     });
 
-    websocket_transport ws_transport(client);
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::none, std::make_shared<trace_log_writer>()) };
 
     ws_transport.connect(_XPLATSTR("http://fakeuri.org")).get();
     ws_transport.disconnect().get();
@@ -168,3 +241,62 @@ TEST(websocket_transport_disconnect, receive_not_called_after_disconnect)
 
     ASSERT_EQ(2, num_called);
 }
+
+template<class T>
+void receive_loop_logs_exception_runner(const T& e, const utility::string_t& expected_message);
+
+TEST(websocket_transport_receive_loop, receive_loop_logs_websocket_exceptions)
+{
+    receive_loop_logs_exception_runner(
+        web_sockets::client::websocket_exception(_XPLATSTR("receive failed")),
+        _XPLATSTR("[websocket transport] websocket exception when receiving data: receive failed\n"));
+}
+
+TEST(websocket_transport_receive_loop, receive_loop_logs_if_receive_task_cancelled)
+{
+    receive_loop_logs_exception_runner(
+        pplx::task_canceled("cancelled"),
+        _XPLATSTR("[websocket transport] receive task cancelled: cancelled\n"));
+}
+
+TEST(websocket_transport_receive_loop, receive_loop_logs_std_exception)
+{
+    receive_loop_logs_exception_runner(
+        std::exception("exception"), 
+        _XPLATSTR("[websocket transport] error receiving response from websocket: exception\n"));
+}
+
+template<class T>
+void receive_loop_logs_exception_runner(const T& e, const utility::string_t& expected_message)
+{
+    pplx::event receive_event;
+    auto client = std::make_shared<test_websocket_client>();
+
+    client->set_receive_function([&receive_event, &e]()->pplx::task<std::string>
+    {
+        receive_event.set();
+        return pplx::task_from_exception<std::string>(e);
+    });
+
+    std::shared_ptr<log_writer> writer(std::make_shared<memory_log_writer>());
+
+    websocket_transport ws_transport{ client, connection_impl::create(_XPLATSTR("http://fake.uri"),
+        _XPLATSTR(""), trace_level::messages, writer) };
+
+    ws_transport.connect(_XPLATSTR("url"))
+        .then([&receive_event]()
+    {
+        receive_event.wait();
+    }).get();
+
+    // this is race'y but there is nothing we can block on
+    pplx::wait(10);
+
+    auto log_entries = std::dynamic_pointer_cast<memory_log_writer>(writer)->get_log_entries();
+
+    ASSERT_FALSE(log_entries.empty());
+
+    auto entry = remove_date_from_log_entry(log_entries[0]);
+
+    ASSERT_EQ(expected_message, entry);
+}