Remove embedded Catch2 and use external repository with tag v3.15.1

Author: cosminpolifronie

CMakeLists.txt

@@ -335,6 +335,13 @@ if (USE_WS OR USE_TEST)
     add_subdirectory(ws)
   endif()
   if (USE_TEST)
+    FetchContent_Declare(Catch2
+      GIT_REPOSITORY "https://github.com/catchorg/Catch2"
+      GIT_TAG "v3.15.1"
+      GIT_SHALLOW 1)
+    
+    FetchContent_MakeAvailable(Catch2)
+
     enable_testing()
     add_subdirectory(test)
   endif()

test/CMakeLists.txt

@@ -63,9 +63,8 @@ target_sources(ixwebsocket_test PRIVATE
     IXTest.cpp
 )
 target_compile_definitions(ixwebsocket_test PRIVATE ${TEST_PROGRAMS_DEFINITIONS})
-target_include_directories(ixwebsocket_test PRIVATE
-  ${PROJECT_SOURCE_DIR}/Catch2/single_include
-)
+
+target_link_libraries(ixwebsocket_test Catch2)
 target_link_libraries(ixwebsocket_test ixwebsocket)
 target_link_libraries(ixwebsocket_test spdlog)
 target_link_libraries(ixwebsocket_test msgpack11)
@@ -75,10 +74,6 @@ foreach(TEST_TARGET_NAME ${TEST_TARGET_NAMES})
     ${TEST_TARGET_NAME}.cpp
   )
 
-  target_include_directories(${TEST_TARGET_NAME} PRIVATE
-    ${PROJECT_SOURCE_DIR}/Catch2/single_include
-  )
-
   target_compile_definitions(${TEST_TARGET_NAME} PRIVATE SPDLOG_COMPILED_LIB=1)
 
   if (APPLE AND USE_TLS)
@@ -89,6 +84,7 @@ foreach(TEST_TARGET_NAME ${TEST_TARGET_NAMES})
   target_link_libraries(${TEST_TARGET_NAME} ixwebsocket_test)
   target_link_libraries(${TEST_TARGET_NAME} ixwebsocket)
 
+  target_link_libraries(${TEST_TARGET_NAME} Catch2)
   target_link_libraries(${TEST_TARGET_NAME} spdlog)
   target_link_libraries(${TEST_TARGET_NAME} msgpack11)