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makeFixture template<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::set class 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 mode return NULL; // => force CRASH return 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)。