Garcon GIT fails building Tests directory

Due the API changes and moves of the code from garcon into libxfce4 and adjustments, Garcon fails building if tests are enabled:

Making install in tests
make[1]: Entering directory '/home/aakcaagac/Documents/garcon-master/tests'
  CC       test_menu_parser-test-menu-parser.o
  CCLD     test-menu-parser
  CC       test_menu_spec-test-menu-spec.o
  CCLD     test-menu-spec
  CC       test_display_menu_gtk3-test-display-menu.o
  CCLD     test-display-menu-gtk3
/usr/bin/ld: ../garcon-gtk/.libs/libgarcon-gtk3-1.so: undefined reference to `STR_IS_EMPTY'
/usr/bin/ld: ../garcon-gtk/.libs/libgarcon-gtk3-1.so: undefined reference to `xfce_expand_field_codes'
collect2: error: ld returned 1 exit status
make[1]: *** [Makefile:530: test-display-menu-gtk3] Error 1
make[1]: Leaving directory '/home/aakcaagac/Documents/garcon-master/tests'
make: *** [Makefile:523: install-recursive] Error 1

It would be nice, if the new code modifications could be applied to the involved Tests code parts.