add LIBBASE122_USE_CONFIG_FILE option to testconsumer

Intended to test config file

test/testconsumer/CMakeLists.txt

@@ -1,15 +1,24 @@
 cmake_minimum_required(VERSION 3.23)
 project(libbase122 LANGUAGES C)
 add_executable(testconsumer testconsumer.c)
-if (NOT DEFINED LIBBASE122_INSTALL_PATH)
-    message(FATAL_ERROR "LIBBASE122_INSTALL_PATH not defined. Define with install path to libbase122.")
-endif ()
-
 if (NOT DEFINED LIBBASE122_USE_SHARED)
     message(FATAL_ERROR "LIBBASE122_USE_SHARED not defined. Define to TRUE or FALSE.")
 endif ()
 
-if (WIN32)
+if (LIBBASE122_USE_CONFIG_FILE)
+    message (STATUS "Trying to find libbase122 with CMake config file...")
+    find_package (Base122 REQUIRED)
+    if (LIBBASE122_USE_SHARED)
+        target_link_libraries (testconsumer base122::shared)
+    else ()
+        target_link_libraries (testconsumer base122::static)
+    endif () # LIBBASE122_USE_SHARED
+elseif (WIN32)
+    if (NOT DEFINED LIBBASE122_INSTALL_PATH)
+        message(FATAL_ERROR "LIBBASE122_INSTALL_PATH not defined. Define with install path to libbase122.")
+    endif ()
+
+    message (STATUS "Trying to find libbase122 at path ${LIBBASE122_INSTALL_PATH}")
     # Convert a Windows path (e.g. C:\foo\bar) to a CMake path (e.g. C:/foo/bar)
     file(TO_CMAKE_PATH "${LIBBASE122_INSTALL_PATH}" LIBBASE122_INSTALL_PATH)
     message(STATUS "${LIBBASE122_INSTALL_PATH}")