Add option to disable unit tests

CMakeLists.txt

@@ -3,6 +3,8 @@ project(json11 VERSION 1.0.0 LANGUAGES CXX)
 
 enable_testing()
 
+option(JSON11_BUILD_TESTS "Build unit tests" ON)
+
 add_library(json11 json11.cpp)
 target_include_directories(json11 PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_compile_options(json11
@@ -10,8 +12,10 @@ target_compile_options(json11
   PRIVATE -fno-rtti -fno-exceptions -Wall -Wextra -Werror)
 configure_file("json11.pc.in" "json11.pc" @ONLY)
 
-add_executable(json11_test test.cpp)
-target_link_libraries(json11_test json11)
+if (JSON11_BUILD_TESTS)
+  add_executable(json11_test test.cpp)
+  target_link_libraries(json11_test json11)
+endif()
 
 install(TARGETS json11 DESTINATION lib)
 install(FILES "${CMAKE_CURRENT_SOURCE_DIR}/json11.hpp" DESTINATION include)