skip WStrings on macOS from FastRTPS to Connext

Signed-off-by: Dirk Thomas <dirk-thomas@users.noreply.github.com>

test_communication/CMakeLists.txt

@@ -171,6 +171,11 @@ if(BUILD_TESTING)
       set(SKIP_TEST "SKIP_TEST")
     endif()
 
+    set(rmw_implementation2_is_connext FALSE)
+    if(rmw_implementation2 MATCHES "(.*)connext(.*)")
+      set(rmw_implementation2_is_connext TRUE)
+    endif()
+
     set(rmw_implementation1_is_opensplice FALSE)
     set(rmw_implementation2_is_opensplice FALSE)
     if(rmw_implementation1 MATCHES "(.*)opensplice(.*)")
@@ -185,6 +190,16 @@ if(BUILD_TESTING)
     set(TEST_MESSAGE_TYPES "")
     foreach(message_file ${message_files})
       get_filename_component(message_type "${message_file}" NAME_WE)
+      # TODO(dirk-thomas) WStrings published by FastRTPS can't be received
+      # correctly by Connext on macOS
+      if(
+        "${message_type}" STREQUAL "WStrings" AND
+        rmw_implementation1_is_fastrtps AND
+        rmw_implementation2_is_connext AND
+        APPLE
+      )
+        continue()
+      endif()
       # TODO(dirk-thomas) OpenSplice doesn't support WString and the rmw impl.
       # maps it to string which has a different wire representation
       if(