diff --git a/.gitignore b/.gitignore
index cf25ac6db..13bc4a7f8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 CMakeLists.txt.user*
+*~
diff --git a/test/system/CMakeLists.txt~ b/test/system/CMakeLists.txt~
deleted file mode 100644
index c5e505571..000000000
--- a/test/system/CMakeLists.txt~
+++ /dev/null
@@ -1,146 +0,0 @@
-# Copyright Takatoshi Kondo 2015
-#
-# Distributed under the Boost Software License, Version 1.0.
-# (See accompanying file LICENSE_1_0.txt or copy at
-# http://www.boost.org/LICENSE_1_0.txt)
-
-CMAKE_MINIMUM_REQUIRED (VERSION 3.8.2)
-
-IF (POLICY CMP0074)
-  CMAKE_POLICY(SET CMP0074 NEW)
-ENDIF ()
-
-OPTION(MQTT_TEST_1 "Build test part1" ON)
-OPTION(MQTT_TEST_2 "Build test part2" ON)
-OPTION(MQTT_TEST_3 "Build test part3" ON)
-OPTION(MQTT_TEST_4 "Build test part4" ON)
-OPTION(MQTT_TEST_5 "Build test part5" ON)
-OPTION(MQTT_TEST_6 "Build test part6" ON)
-OPTION(MQTT_TEST_7 "Build test part7" ON)
-
-IF (MQTT_TEST_1)
-    LIST (APPEND check_PROGRAMS
-        connect.cpp
-        underlying_timeout.cpp
-        topic_alias_recv.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_2)
-    LIST (APPEND check_PROGRAMS
-        length_check.cpp
-        utf8string_validate.cpp
-        packet_id.cpp
-        remaining_length.cpp
-        message.cpp
-        property.cpp
-        broker_offline_message.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_3)
-    LIST (APPEND check_PROGRAMS
-        sub.cpp
-        pubsub_1.cpp
-        pubsub_2.cpp
-        pubsub_no_strand.cpp
-        multi_sub.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_4)
-    LIST (APPEND check_PROGRAMS
-        async_pubsub_1.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_5)
-    LIST (APPEND check_PROGRAMS
-        resend.cpp
-        resend_new_client.cpp
-        resend_serialize.cpp
-        resend_serialize_ptr_size.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_6)
-    LIST (APPEND check_PROGRAMS
-        offline.cpp
-        manual_publish.cpp
-        retain_1.cpp
-        retain_2.cpp
-        will.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_7)
-    LIST (APPEND check_PROGRAMS
-        as_buffer_sub.cpp
-        as_buffer_pubsub.cpp
-        as_buffer_async_pubsub_1.cpp
-        as_buffer_async_pubsub_2.cpp
-        subscription_map.cpp
-        retained_topic_map.cpp
-        subscription_map_broker.cpp
-        retained_topic_map_broker.cpp
-        async_pubsub_2.cpp
-    )
-ENDIF ()
-
-FIND_PACKAGE (Boost 1.67.0 REQUIRED COMPONENTS unit_test_framework)
-
-# Without this setting added, azure pipelines completely fails to find the boost libraries. No idea why.
-IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-    LINK_DIRECTORIES(${Boost_LIBRARY_DIRS})
-ENDIF ()
-
-FOREACH (source_file ${check_PROGRAMS})
-    GET_FILENAME_COMPONENT (source_file_we ${source_file} NAME_WE)
-    ADD_EXECUTABLE (${source_file_we} ${source_file})
-    TARGET_COMPILE_DEFINITIONS (${source_file_we} PUBLIC $<IF:$<BOOL:${MQTT_USE_STATIC_BOOST}>,,BOOST_TEST_DYN_LINK>)
-    TARGET_LINK_LIBRARIES (
-        ${source_file_we} mqtt_cpp_iface Boost::unit_test_framework
-    )
-    IF (MQTT_USE_LOG)
-        TARGET_COMPILE_DEFINITIONS (${source_file_we} PUBLIC $<IF:$<BOOL:${MQTT_USE_STATIC_BOOST}>,,BOOST_LOG_DYN_LINK>)
-        TARGET_LINK_LIBRARIES (
-            ${source_file_we} Boost::log
-        )
-    ENDIF ()
-    IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-        IF (MQTT_CODECOV)
-            SET_PROPERTY (TARGET ${source_file_we}
-                          APPEND_STRING PROPERTY COMPILE_FLAGS " -O0 -g --coverage -fno-inline")
-            SET_PROPERTY (TARGET ${source_file_we}
-                          APPEND_STRING PROPERTY LINK_FLAGS " --coverage")
-        ENDIF ()
-    ENDIF ()
-    IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-        IF (CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
-            STRING(REGEX REPLACE "/W[0-4]" "/W3" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-        ELSE ()
-            SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W3")
-        ENDIF ()
-    ENDIF ()
-
-    # Running test with arguments
-    # CTEST_ARGS="--log_level=all" ctest -V
-    IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-        ADD_TEST (NAME ${source_file_we} COMMAND ${CMAKE_CURRENT_BINARY_DIR}/${source_file_we})
-    ELSE ()
-        ADD_TEST (NAME ${source_file_we} COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/args_provider.sh ${CMAKE_CURRENT_BINARY_DIR}/${source_file_we})
-    ENDIF ()
-    set_tests_properties(${source_file_we} PROPERTIES TIMEOUT 300)
-ENDFOREACH ()
-
-IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/mosquitto.org.crt DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.crt.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.key.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/cacert.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-ELSE ()
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/mosquitto.org.crt DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.crt.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.key.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/cacert.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-ENDIF ()
diff --git a/test/system/st_pp.cpp b/test/system/st_pp.cpp
deleted file mode 100644
index 6d8d9a59f..000000000
--- a/test/system/st_pp.cpp
+++ /dev/null
@@ -1,26 +0,0 @@
-#if !defined(MQTT_TLS_ERROR_COMPARISON)
-
-#if defined(SSL_R_SHORT_READ)
-
-#define MQTT_TLS_ERROR_COMPARISON ERR_GET_REASON(error_val) == SSL_R_SHORT_READ;
-
-#else // defined(SSL_R_SHORT_READ)
-
-#define MQTT_TLS_ERROR_COMPARISON ERR_GET_REASON(error_val) == tls::error::stream_truncated;
-
-#endif // defined(SSL_R_SHORT_READ)
-
-#endif // !defined(MQTT_TLS_ERROR_COMPARISON)
-
-
-        if (   (ec == as::error::eof)
-            || (ec == as::error::connection_reset)
-            || (ec == as::error::operation_aborted)
-#if defined(MQTT_USE_WS)
-            || (ec == boost::beast::websocket::error::closed)
-#endif // defined(MQTT_USE_WS)
-#if defined(MQTT_USE_TLS)
-            || (MQTT_TLS_ERROR_COMPARISON)
-#endif // defined(MQTT_USE_TLS)
-        ) {
-        }
diff --git a/test/unit/CMakeLists.txt~ b/test/unit/CMakeLists.txt~
deleted file mode 100644
index c5e505571..000000000
--- a/test/unit/CMakeLists.txt~
+++ /dev/null
@@ -1,146 +0,0 @@
-# Copyright Takatoshi Kondo 2015
-#
-# Distributed under the Boost Software License, Version 1.0.
-# (See accompanying file LICENSE_1_0.txt or copy at
-# http://www.boost.org/LICENSE_1_0.txt)
-
-CMAKE_MINIMUM_REQUIRED (VERSION 3.8.2)
-
-IF (POLICY CMP0074)
-  CMAKE_POLICY(SET CMP0074 NEW)
-ENDIF ()
-
-OPTION(MQTT_TEST_1 "Build test part1" ON)
-OPTION(MQTT_TEST_2 "Build test part2" ON)
-OPTION(MQTT_TEST_3 "Build test part3" ON)
-OPTION(MQTT_TEST_4 "Build test part4" ON)
-OPTION(MQTT_TEST_5 "Build test part5" ON)
-OPTION(MQTT_TEST_6 "Build test part6" ON)
-OPTION(MQTT_TEST_7 "Build test part7" ON)
-
-IF (MQTT_TEST_1)
-    LIST (APPEND check_PROGRAMS
-        connect.cpp
-        underlying_timeout.cpp
-        topic_alias_recv.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_2)
-    LIST (APPEND check_PROGRAMS
-        length_check.cpp
-        utf8string_validate.cpp
-        packet_id.cpp
-        remaining_length.cpp
-        message.cpp
-        property.cpp
-        broker_offline_message.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_3)
-    LIST (APPEND check_PROGRAMS
-        sub.cpp
-        pubsub_1.cpp
-        pubsub_2.cpp
-        pubsub_no_strand.cpp
-        multi_sub.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_4)
-    LIST (APPEND check_PROGRAMS
-        async_pubsub_1.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_5)
-    LIST (APPEND check_PROGRAMS
-        resend.cpp
-        resend_new_client.cpp
-        resend_serialize.cpp
-        resend_serialize_ptr_size.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_6)
-    LIST (APPEND check_PROGRAMS
-        offline.cpp
-        manual_publish.cpp
-        retain_1.cpp
-        retain_2.cpp
-        will.cpp
-    )
-ENDIF ()
-
-IF (MQTT_TEST_7)
-    LIST (APPEND check_PROGRAMS
-        as_buffer_sub.cpp
-        as_buffer_pubsub.cpp
-        as_buffer_async_pubsub_1.cpp
-        as_buffer_async_pubsub_2.cpp
-        subscription_map.cpp
-        retained_topic_map.cpp
-        subscription_map_broker.cpp
-        retained_topic_map_broker.cpp
-        async_pubsub_2.cpp
-    )
-ENDIF ()
-
-FIND_PACKAGE (Boost 1.67.0 REQUIRED COMPONENTS unit_test_framework)
-
-# Without this setting added, azure pipelines completely fails to find the boost libraries. No idea why.
-IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-    LINK_DIRECTORIES(${Boost_LIBRARY_DIRS})
-ENDIF ()
-
-FOREACH (source_file ${check_PROGRAMS})
-    GET_FILENAME_COMPONENT (source_file_we ${source_file} NAME_WE)
-    ADD_EXECUTABLE (${source_file_we} ${source_file})
-    TARGET_COMPILE_DEFINITIONS (${source_file_we} PUBLIC $<IF:$<BOOL:${MQTT_USE_STATIC_BOOST}>,,BOOST_TEST_DYN_LINK>)
-    TARGET_LINK_LIBRARIES (
-        ${source_file_we} mqtt_cpp_iface Boost::unit_test_framework
-    )
-    IF (MQTT_USE_LOG)
-        TARGET_COMPILE_DEFINITIONS (${source_file_we} PUBLIC $<IF:$<BOOL:${MQTT_USE_STATIC_BOOST}>,,BOOST_LOG_DYN_LINK>)
-        TARGET_LINK_LIBRARIES (
-            ${source_file_we} Boost::log
-        )
-    ENDIF ()
-    IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-        IF (MQTT_CODECOV)
-            SET_PROPERTY (TARGET ${source_file_we}
-                          APPEND_STRING PROPERTY COMPILE_FLAGS " -O0 -g --coverage -fno-inline")
-            SET_PROPERTY (TARGET ${source_file_we}
-                          APPEND_STRING PROPERTY LINK_FLAGS " --coverage")
-        ENDIF ()
-    ENDIF ()
-    IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-        IF (CMAKE_CXX_FLAGS MATCHES "/W[0-4]")
-            STRING(REGEX REPLACE "/W[0-4]" "/W3" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-        ELSE ()
-            SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W3")
-        ENDIF ()
-    ENDIF ()
-
-    # Running test with arguments
-    # CTEST_ARGS="--log_level=all" ctest -V
-    IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-        ADD_TEST (NAME ${source_file_we} COMMAND ${CMAKE_CURRENT_BINARY_DIR}/${source_file_we})
-    ELSE ()
-        ADD_TEST (NAME ${source_file_we} COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/args_provider.sh ${CMAKE_CURRENT_BINARY_DIR}/${source_file_we})
-    ENDIF ()
-    set_tests_properties(${source_file_we} PROPERTIES TIMEOUT 300)
-ENDFOREACH ()
-
-IF ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/mosquitto.org.crt DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.crt.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.key.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/cacert.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/Release)
-ELSE ()
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/mosquitto.org.crt DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.crt.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/server.key.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-   FILE(COPY ${CMAKE_CURRENT_SOURCE_DIR}/../test/certs/cacert.pem DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-ENDIF ()