PoC Implementation of Boost.Test-Like Test Suite Hook Mechanism.

PoC.cc

#include <iostream>
#include <list>

using namespace std;

// | 
// | Start of Boost.Test Header.
// v
using Invoker = void (*)();

class TestCaseBase {
 public:
  virtual void DoTest()=0;
};

class Framework {
 public:
  void Traverse() {
    for (auto& t : test_cases_) {
      t();
    };
  }
  void Register(Invoker test_case) {
    test_cases_.push_back(test_case);
  };
 private:
  list<Invoker> test_cases_;
};

Framework framework;

class Registerar {
 public:
  Registerar(Invoker test_case) {
    framework.Register(test_case);
  }
};

struct has_setup {
  template<typename T>
  static auto check(T&& t) -> decltype(t.setup(), true_type {});
  template<typename T>
  static auto check(...) -> false_type;
};

template<typename T>
struct is_setup_fixture : public decltype(has_setup::check<T>(declval<T>())) {};

template<typename T, typename enable_if<is_setup_fixture<T>::value, nullptr_t>::type=nullptr>
void unit_test_setup_conditional(T&& t) {
  t.setup();
}

template<typename T, typename enable_if<!is_setup_fixture<T>::value, nullptr_t>::type=nullptr>
void unit_test_setup_conditional(T&& t) {}

struct has_teardown {
  template<typename T>
  static auto check(T&& t) -> decltype(t.teardown(), true_type {});
  template<typename T>
  static auto check(...) -> false_type;
};

template<typename T>
struct is_teardown_fixture : public decltype(has_teardown::check<T>(declval<T>())) {};

template<typename T, typename enable_if<is_teardown_fixture<T>::value, nullptr_t>::type=nullptr>
void unit_test_teardown_conditional(T&& t) {
  t.teardown();
}

template<typename T, typename enable_if<!is_setup_fixture<T>::value, nullptr_t>::type=nullptr>
void unit_test_teardown_conditional(T&& t) {}

int main(int argc, char* argv[]) {
  framework.Traverse();
  return 0;
}
// ^ 
// | End of Boost.Test Header.
// |

// | 
// | Lines below are macro-expanded user defined code.
// v
class TestFixture {
 public:
  TestFixture() { cout << "setup " << endl; }
  ~TestFixture() { cout << "teardown" << endl; }
  void setup() { cout << "optional setup" << endl; }
  void teardown() { cout << "optional teardown" << endl; }
};

class TestCase : public TestCaseBase, public TestFixture {
 public:
  void DoTest();
};

static void invoke() {
  cout << "fixture ctor" << endl;
  TestCase test_case;
  cout << "fixture setup" << endl;
  unit_test_setup_conditional(test_case);
  cout << "test entry" << endl;
  test_case.DoTest();
  cout << "fixture teardown" << endl;
  unit_test_teardown_conditional(test_case);
  cout << "fixture dtor" << endl;
}

Registerar registerar(&invoke);

void TestCase::DoTest() {
  cout << "Do test." << endl;
}