node/test/addons-napi/common.h

// Empty value so that macros here are able to return NULL or void
#define NAPI_RETVAL_NOTHING  // Intentionally blank #define

#define GET_AND_THROW_LAST_ERROR(env)                                    \
  do {                                                                   \
    bool is_pending;                                                     \
    napi_is_exception_pending((env), &is_pending);                       \
    /* If an exception is already pending, don't rethrow it */           \
    if (!is_pending) {                                                   \
      const napi_extended_error_info* error_info;                        \
      napi_get_last_error_info((env), &error_info);                      \
      const char* error_message = error_info->error_message != NULL ?    \
        error_info->error_message :                                      \
        "empty error message";                                           \
      napi_throw_error((env), error_message);                            \
    }                                                                    \
  } while(0);

#define NAPI_ASSERT_BASE(env, assertion, message, ret_val)               \
  if (!(assertion)) {                                                    \
    napi_throw_error(                                                    \
        (env),                                                           \
        "assertion (" #assertion ") failed: " message);                  \
    return ret_val;                                                      \
  }

// Returns NULL on failed assertion.
// This is meant to be used inside napi_callback methods.
#define NAPI_ASSERT(env, assertion, message)                             \
  NAPI_ASSERT_BASE(env, assertion, message, NULL)

// Returns empty on failed assertion.
// This is meant to be used inside functions with void return type.
#define NAPI_ASSERT_RETURN_VOID(env, assertion, message)                 \
  NAPI_ASSERT_BASE(env, assertion, message, NAPI_RETVAL_NOTHING)

#define NAPI_CALL_BASE(env, the_call, ret_val)                           \
  if ((the_call) != napi_ok) {                                           \
    GET_AND_THROW_LAST_ERROR((env));                                     \
    return ret_val;                                                      \
  }

// Returns NULL if the_call doesn't return napi_ok.
#define NAPI_CALL(env, the_call)                                         \
  NAPI_CALL_BASE(env, the_call, NULL)

// Returns empty if the_call doesn't return napi_ok.
#define NAPI_CALL_RETURN_VOID(env, the_call)                             \
  NAPI_CALL_BASE(env, the_call, NAPI_RETVAL_NOTHING)

#define DECLARE_NAPI_PROPERTY(name, func)                                \
  { (name), 0, (func), 0, 0, 0, napi_default, 0 }