A simple fix I came up with, which is only valid for MSVC and GCC/LLVM, is:
#ifdef  _WIN32
#define JOFF        0
#define JON         -1
#else
#define JOFF        0
#define JON         1
#endif
typedef enum { SERIAL = JOFF, PARALLEL = JON } TEST_MODE_e;
solved MSVC 1 bit enum type equals -1 and equality test fails