学习笔记：解读CppUnit源码3

 Test类就是抽象我们的测试用例的，那么Test类是直接new来创建的吗？当然不是的。在创建设计模式中，有一种创建叫做TestFactory。就是工厂模式。

TestFactory.h

class CPPUNIT_API MyTestFactory {public:virtual ~MyTestFactory() {};//创建一个Test实例virtual MyTest* makeTest() = 0;};

既然Test类是抽象类，那么工厂当然也是抽象的也就不奇怪了。对应装置器也应该有一个创建工厂：TestFixtureFactory

TestFixtureFactory.h

class MyTestFixtureFactory{public://TestFixture的工厂virtual MyTestFixture *makeFixture() =0;virtual ~MyTestFixtureFactory() {};};//在CPPUNIT_TEST()处调用makeFixturetemplate<class TestFixtureType>class MyConcretTestFixtureFactory : public CPPUNIT_NS::MyTestFixtureFactory{MyTestFixture *makeFixture(){return new TestFixtureType();}};

TestFixtureFactory是对应抽象的类，ConcretTestFixtureFactory当然是实现类了,而ConcretTestFixtureFactory类也用到了类模板。这个类模板参数是什么就从工厂里创建什么类。在用宏来创建对象的情况下，这个设计是相当的灵活阿。

下面再看看第三个工厂。也是一个很重要的工厂：TestSuiteFactory

TestSuiteFactory.h

//TestFixture子类的类工厂template<typename TestCaseType>class MyTestSuiteFactory : public MyTestFactory{public:virtual MyTest *makeTest(){return TestCaseType::suite();}};

这个工厂也用了模板参数，作用嘛和第二个讲的道理一样。调用指定类的suite方法，那么suite方法是在哪里的呢？是在CPPUNIT_TEST_SUITE_END宏所展开的代码里。也就是调用主测类的一个叫suite名字的静态方法。

下面回到工厂的正题：TestFactory的实现类，

TestFactoryRegistry.h

#define CppUnitSet std::setclass CPPUNIT_API MyTestFactoryRegistry : public MyTestFactory{public:MyTestFactoryRegistry( std::string name ):m_name( name ){};virtual ~MyTestFactoryRegistry(){};virtual MyTest *makeTest(){// 创建一个测试包，并冠以m_name的名称MyTestSuite *suite = new MyTestSuite( m_name );//以将其下所属的测试实例添加到suite中addTestToSuite( suite );return suite;};//用名字去创建工厂，单例模式static MyTestFactoryRegistry* getRegistry( const std::string &name = "All Tests" );void addTestToSuite( MyTestSuite *suite ){Factories::iterator it = m_factories.begin();for (;it != m_factories.end(); ++it ){//把一组工厂创建的测试实例加入到组(suite)中MyTestFactory *factory = *it;suite->addTest(factory->makeTest());}};//注册一个工厂(子类)void registerFactory( MyTestFactory *factory ){m_factories.insert( factory );};//注销一个工厂(子类)void unregisterFactory( MyTestFactory *factory ){m_factories.erase( factory );};//用名字注册一个工厂void addRegistry( const std::string &name );//是否有效static bool isValid();private:MyTestFactoryRegistry( const MyTestFactoryRegistry © );MyTestFactoryRegistry &operator =( const MyTestFactoryRegistry © );private://所有测试用例的工厂都是单独存在的不可能会有两个，所以选用了Set这个数据结构typedef CppUnitSet<MyTestFactory *, std::less<MyTestFactory*> > Factories;Factories m_factories;std::string m_name;//一组工厂的名字};

TestFactoryRegistry.cpp

//用名字去创建工厂，单例模式MyTestFactoryRegistry* MyTestFactoryRegistry::getRegistry( const std::string &name){return TestFactoryRegistryList::getRegistry( name );};bool MyTestFactoryRegistry::isValid(){return TestFactoryRegistryList::isValid();};void MyTestFactoryRegistry::addRegistry( const std::string &name ){registerFactory( getRegistry( name ) );};

TestFactoryRegistryList类存在于TestFactoryRegistry.cpp中，是用来管理测试用例工厂的类

////////////////////////////////////////////////////////////////////////////一个管理类，用以管理所有的注册项——TestFactoryRegistry类的实例class TestFactoryRegistryList{private://注册名称-注册项的映射表typedef CppUnitMap<std::string, MyTestFactoryRegistry *, std::less<std::string> > Registries;Registries m_registries;enum State {doNotChange =0,notCreated,exist,destroyed};static State stateFlag( State newState = doNotChange ){static State state = notCreated;if ( newState != doNotChange )state = newState;return state;}static TestFactoryRegistryList *getInstance(){//使用了静态变量来实现单例模式static TestFactoryRegistryList list;return &list;}//用名字查找&&创建实体MyTestFactoryRegistry *getInternalRegistry( const std::string &name ){Registries::const_iterator foundIt = m_registries.find( name );if ( foundIt == m_registries.end() )//没有找到实体就创建{MyTestFactoryRegistry *factory = new MyTestFactoryRegistry( name );m_registries.insert( std::pair<const std::string, MyTestFactoryRegistry*>( name, factory ) );return factory;}//找到实体return (*foundIt).second;}public:TestFactoryRegistryList(){stateFlag( exist );}~TestFactoryRegistryList(){for ( Registries::iterator it = m_registries.begin(); it != m_registries.end(); ++it )delete (*it).second;stateFlag( destroyed );}//用名字这个关键字在获得一个实体static MyTestFactoryRegistry *getRegistry( const std::string &name ){assert( isValid() );if ( !isValid() ) // release modereturn NULL; // => force CRASHreturn getInstance()->getInternalRegistry( name );}//是否销毁static bool isValid(){return stateFlag() != destroyed;}};

关于TestFactoryRegistry的代码个人觉得比较难懂。首先想说明的是TestFactoryRegistryList里面其实是一组测试用例工厂，每个工厂是以名字为关键字，所以工厂list的主要数据结构是map。而TestFactoryRegistry的数据结构set中，包含的是自身，所以这样就有了层次结构了。当然在真实的代码中，TestFactoryRegistryList是inner class。

下面介绍最后一个与创建相关的类：

AutoRegisterSuite.h

//自动注册指定类型的测试包//用CPPUNIT_TEST_SUITE_REGISTRATION()和CPPUNIT_TEST_SUITE_NAMED_REGISTRATION()//这两个方法来访问．template<class TestCaseType>class MyAutoRegisterSuite{public:MyAutoRegisterSuite(): m_registry( &MyTestFactoryRegistry::getRegistry() ){MyTestFactory * m_factory = new MyTestSuiteFactory<TestCaseType>();m_registry->registerFactory( &m_factory );}MyAutoRegisterSuite( const std::string &name ): m_registry( &MyTestFactoryRegistry::getRegistry( name ) ){MyTestFactory * m_factory = new MyTestSuiteFactory<TestCaseType>();m_registry->registerFactory( &m_factory );}~MyAutoRegisterSuite(){if ( MyTestFactoryRegistry::isValid() )m_registry->unregisterFactory( &m_factory );}private:MyTestFactoryRegistry *m_registry;MyTestSuiteFactory<TestCaseType> m_factory;};

又看到模板类的参数了，TestCaseType的作用和前面一样，为了让类增加灵活性。而它的两个聚合物一个是TestFactoryRegistry，而另一个是TestSuiteFactory<TestCaseType>，这个用来管理调用具体主测类的Suite的创建的工厂。

有些人一定也注意到了，TestFactoryRegistry的父类是TestFactory，而TestSuiteFactory的父类也是TestFactory。所以说白了这里就是将一组测试包(TestSuiteFactory)注册到TestFactoryRegistry中。那么如果名字相同怎么办呢？这个嘛TestFactoryRegistry::getRegistry(name)是单例模式,是否注册就让它去决定把。(单例嘛当然只有一份实体)。