add test (doctest)

CMakeLists.txt

@@ -16,6 +16,26 @@ set(ADC_DEVICE_HEADERS
     device/adc_device_command.h
 )
 
+option(BUILD_TESTS "Buiuld tests" ON)
+
+if (BUILD_TESTS)
+    find_package(doctest)
+
+    set(VALUEHOLDER_TEST_APP adc_valueholder_test)
+    add_executable(${VALUEHOLDER_TEST_APP} tests/adc_valueholder_test.cpp)
+
+    if (NOT doctest_FOUND)
+        include(FetchContent)
+        FetchContent_Declare(
+            doctest
+            GIT_REPOSITORY https://github.com/doctest/doctest.git
+            GIT_TAG 2.4.11
+        )
+        FetchContent_MakeAvailable(doctest)
+    endif()
+
+    target_link_libraries(${VALUEHOLDER_TEST_APP} PRIVATE doctest::doctest)
+endif(BUILD_TESTS)
 
 include(GNUInstallDirs)