cpp-game-engine/engine/test/game_dispatch_test.cxx

//
//  game_dispatch_test.cxx
//  engine-test
//
//  Created by Sam Jaffe on 7/10/19.
//  Copyright © 2019 Sam Jaffe. All rights reserved.
//

#include <memory>

#include <gmock/gmock.h>

#include "game/engine/events.hpp"
#include "game/engine/game_dispatch.hpp"
#include "game/engine/scene.hpp"
#include "game/graphics/renderer.hpp"

#include "mock_renderer.h"

struct mock_scene : engine::scene {
  mock_scene(std::shared_ptr<engine::game_dispatch> game)
      : engine::scene("mock", game) {}
  MOCK_METHOD1(update, void(float));
  MOCK_METHOD1(render, void(graphics::renderer &));
  MOCK_METHOD1(handle_key_event, void(engine::event::key_event));
  MOCK_METHOD1(handle_mouse_event, void(engine::event::mouse_event));
};

class GameDispatchTest : public testing::Test {
protected:
  void SetUp() override;
  void TearDown() override;

  mock_scene & scene() const { return *scene_; }
  engine::game_dispatch & game() const { return *dispatch_; }

private:
  std::shared_ptr<stub_renderer> renderer_;
  std::shared_ptr<engine::game_dispatch> dispatch_;
  std::shared_ptr<mock_scene> scene_;
};

void GameDispatchTest::SetUp() {
  renderer_.reset(new stub_renderer);
  dispatch_.reset(new engine::game_dispatch(renderer_));
  scene_.reset(new mock_scene(dispatch_));
  game().register_scene(scene_);
  game().activate_scene("mock");
}

void GameDispatchTest::TearDown() {
  scene_.reset();
  dispatch_.reset();
  renderer_.reset();
}

using testing::AnyNumber;
using testing::Ge;
using testing::Lt;
using testing::_;

TEST_F(GameDispatchTest, UpdateDispatchesToCurrentScene) {
  EXPECT_CALL(scene(), update(_)).Times(1);
  game().update();
}

TEST_F(GameDispatchTest, UpdateIsCappedInFrequencyByFPSParam) {
  EXPECT_CALL(scene(), update(Ge(1.0 / 60.0))).Times(AnyNumber());
  EXPECT_CALL(scene(), update(Lt(1.0 / 60.0))).Times(0);
  for (int i = 0; i < 10; i++) {
    game().update();
  }
}

TEST_F(GameDispatchTest, RenderDispatchesToCurrentScene) {
  EXPECT_CALL(scene(), render(_)).Times(1);
  game().render();
}