对程序进行单元测试时,有时我们会遇到一些小麻烦,比如某些操作十分耗时,有些依赖的对象不易获取等等,这时我们就可以通过Groovy Mock或Groovy Stub来解决这些问题。Mock对方法调用的次数十分敏感,如果程序中调用的次数不在期望的调用次数范围内,则会抛出异常以致测试失败;而Stub仅仅是起到‘替身’的作用,它并不关心方法调用与否,即使方法一次都没被调用,也不会抛出异常导致测试失败。
下面让我们来看一个实际的例子吧: import groovy.mock.interceptor.*
class User { String name String address String toString() { "Name: $name, Address: $address" } }
class UserDao { User findUserByName(String name) { if ('山风小子' == name) return new User(name:name, address:'Shanghai') else return new User(name:'Anonymous User', address:'Unknown') } }
class ShowUserInfoService { UserDao userDao = new UserDao() def showInfo(String name) { User user = userDao.findUserByName('山风小子') println user } }
/* 平时下面这些代码写于单元测试中,为了简洁起见,单独抽取出来 */
def userDaoMock = new MockFor(UserDao) /* UserDao对象中的findUserByName方法必须被调用1~2次,否则测试失败 同时将findUserByName方法的实现替换为return new User(name:'mock user', address:'Unknown') */ userDaoMock.demand.findUserByName(1..2) { String name -> return new User(name:'mock user', address:'Unknown') }
userDaoMock.use { def showUserInfoService = new ShowUserInfoService() showUserInfoService.showInfo('山风小子') showUserInfoService.showInfo('Daniel.Sun') //showUserInfoService.showInfo('BlueSUN') }
def userDaoStub = new StubFor(UserDao) /* 仅仅将findUserByName方法的实现替换为return new User(name:'stub user', address:'Unknown') 即使findUserByName方法不被调用,测试也不会失败 */ userDaoStub.demand.findUserByName { String name -> return new User(name:'stub user', address:'Unknown') }
userDaoStub.use { def showUserInfoService = new ShowUserInfoService() showUserInfoService.showInfo('山风小子') } 运行结果: Name: mock user, Address: Unknown Name: mock user, Address: Unknown Name: stub user, Address: Unknown
|