cpp-mathematic-limit/test/limit_test.cxx

//
//  limit_test.cxx
//  limit
//
//  Created by Sam Jaffe on 2/3/17.
//
#pragma once

#include "math/limit.h"

#include <cxxtest/TestSuite.h>

class bound_number_TestSuite : public CxxTest::TestSuite {
public:
  using number_t = bound_number<int, -5, +7>;
  
//  Fails to compile because of well-ordered principle
//  void test_bounds_compiler_error() {
//    bound_number<int, 0, -1>(0);
//  }
  
  void test_number_construct_inbounds() {
    number_t n{0};
    TS_ASSERT_EQUALS(n, 0);
  }
  
  void test_number_validate_oob_low() {
    TS_ASSERT_THROWS((number_t{check_bounds, -6}), std::out_of_range);
  }

  void test_number_validate_oob_high() {
    TS_ASSERT_THROWS((number_t{check_bounds, +8}), std::out_of_range);
  }

  void test_number_cannot_construct_oob_low() {
    number_t n{-6};
    TS_ASSERT_EQUALS(n, number_t::min);
  }
  
  void test_number_cannot_construct_oob_high() {
    number_t n{10};
    TS_ASSERT_EQUALS(n, number_t::max);
  }
  
  void test_number_cannot_increment_above_limit() {
    number_t n{+7};
    TS_ASSERT_EQUALS(n++, number_t::max);
    TS_ASSERT_EQUALS(n, number_t::max);
  }

  void test_number_cannot_decrement_below_limit() {
    number_t n{-5};
    TS_ASSERT_EQUALS(n--, number_t::min);
    TS_ASSERT_EQUALS(n, number_t::min);
  }
};