{
FileStatus status( mFileNameExist );
CPPUNIT_ASSERT_EQUAL( status.getFileName(), mFileNameExist );
}
void testGetFileSize()
{
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT_EQUAL( exist.getFileSize(), (DWORD)FILE_SIZE );
FileStatus notExist( mFileNameNotExist );
CPPUNIT_ASSERT_THROW( notExist.getFileSize(), FileStatusError );
}
void testFileExist()
{
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT( exist.fileExist() );
FileStatus notExist( mFileNameNotExist );
CPPUNIT_ASSERT( ! notExist.fileExist() );
}
void testFileModifyDateBasic()
{
FILETIME fileTime;
GetSystemTimeAsFileTime( &fileTime );
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT_NO_THROW( exist.getFileModifyDate() );
CPPUNIT_ASSERT_NO_THROW( exist.setFileModifyDate( &fileTime ) );
FileStatus notExist( mFileNameNotExist );
CPPUNIT_ASSERT_THROW( exist.getFileModifyDate(), FileStatusError );
CPPUNIT_ASSERT_THROW( exist.setFileModifyDate( &fileTime ), FileStatusError );
}
void testFileModifyDateEqual()
{
FILETIME fileTime;
GetSystemTimeAsFileTime( &fileTime );
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT_NO_THROW( exist.setFileModifyDate( &fileTime ) );
FILETIME get = exist.getFileModifyDate();
CPPUNIT_ASSERT( CompareFileTime( &get, &fileTime ) == 0 );
}
};
int main()
{
CPPUNIT_NS::TestResult r;
CPPUNIT_NS::TestResultCollector result;
r.addListener( &result );
CPPUNIT_NS::TestCallertestCase1( "testCtorAndGetName", MyTestCase::testCtorAndGetName );
CPPUNIT_NS::TestCallertestCase2( "testGetFileSize", MyTestCase::testGetFileSize );
CPPUNIT_NS::TestCallertestCase3( "testFileExist", MyTestCase::testFileExist );
CPPUNIT_NS::TestCallertestCase4( "testFileModifyDateBasic", MyTestCase::testFileModifyDateBasic );
CPPUNIT_NS::TestCallertestCase5( "testFileModifyDateEqual", MyTestCase::testFileModifyDateEqual );
testCase1.run( &r );
testCase2.run( &r );
testCase3.run( &r );
testCase4.run( &r );
testCase5.run( &r );
CPPUNIT_NS::TextOutputter out( &result, std::cout );
out.write();
return 0;
}
运行测试，发现两个错误：
1) test: testFileModifyDateBasic (F) line: 140 c:unittestunittest.cpp
assertion failed
- Unexpected exception caught
2) test: testFileModifyDateEqual (F) line: 150 c:unittestunittest.cpp
assertion failed
- Unexpected exception caught
调试发现，原来我的setFileModifyDate中，文件的打开方式为GENERIC_READ，只有读权限，自然不能写。把这个替换为 GENERIC_READ | GENERIC_WRITE，再运行，一切OK！
其实上面的测试以及实现代码还有一些问题，譬如说，测试用例分得还不够细，有些测试可以继续细分为几个函数，这样一旦遇到测试错误，你可以很精确的知道错误的位置（因为抛出异常错误是不能知道行数的）。不过用来说明怎样进行测试驱动开发应该是足够了。
VI. 测试集
CPPUNIT_NS::TestCallertestCase1( "testCtorAndGetName", MyTestCase::testCtorAndGetName );
CPPUNIT_NS::TestCallertestCase2( "testGetFileSize", MyTestCase::testGetFileSize );
CPPUNIT_NS::TestCallertestCase3( "testFileExist", MyTestCase::testFileExist );
CPPUNIT_NS::TestCallertestCase4( "testFileModifyDateBasic", MyTestCase::testFileModifyDateBasic );
CPPUNIT_NS::TestCallertestCase5( "testFileModifyDateEqual", MyTestCase::testFileModifyDateEqual );
这段代码虽然还不够触目惊心，但是让程序员来做这个，的确是太浪费了。CppUnit为我们提供了一些机制来避免这样的浪费。我们可以修改我们的测试代码为：
class MyTestCase:public CPPUNIT_NS::TestFixture
{
std::string mFileNameExist;
std::string mFileNameNotExist;
std::string mTestFolder;
enum DUMMY
{
FILE_SIZE = 1011
};
CPPUNIT_TEST_SUITE( MyTestCase );
CPPUNIT_TEST( testCtorAndGetName );
CPPUNIT_TEST( testGetFileSize );
CPPUNIT_TEST( testFileExist );
CPPUNIT_TEST( testFileModifyDateBasic );
CPPUNIT_TEST( testFileModifyDateEqual );
CPPUNIT_TEST_SUITE_END();
public:
virtual void setUp()
{
mTestFolder = "c:justfortest";
mFileNameExist = mTestFolder + "exist.dat";
mFileNameNotExist = mTestFolder + "notexist.dat";
if( GetFileAttributes( mTestFolder.c_str() ) != INVALID_FILE_ATTRIBUTES )
throw std::exception( "test folder already exists" );
if( ! CreateDirectory( mTestFolder.c_str() ,NULL ) )
throw std::exception( "cannot create folder" );
HANDLE file = CreateFile( mFileNameExist.c_str(), GENERIC_READ | GENERIC_WRITE,
0, NULL, CREATE_NEW, 0, NULL );
if( file == INVALID_HANDLE_VALUE )
throw std::exception( "cannot create file" );
char buffer[FILE_SIZE];
DWORD bytesWritten;
if( !WriteFile( file, buffer, FILE_SIZE, &bytesWritten, NULL ) ||
bytesWritten != FILE_SIZE )
{
CloseHandle( file );
throw std::exception( "cannot write file" );
}
CloseHandle( file );
}
virtual void tearDown()
{
if( ! DeleteFile( mFileNameExist.c_str() ) )
throw std::exception( "cannot delete file" );
if( ! RemoveDirectory( mTestFolder.c_str() ) )
throw std::exception( "cannot remove folder" );
}
void testCtorAndGetName()
{
FileStatus status( mFileNameExist );
CPPUNIT_ASSERT_EQUAL( status.getFileName(), mFileNameExist );
}
void testGetFileSize()
{
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT_EQUAL( exist.getFileSize(), (DWORD)FILE_SIZE );
FileStatus notExist( mFileNameNotExist );
CPPUNIT_ASSERT_THROW( notExist.getFileSize(), FileStatusError );
}
void testFileExist()
{
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT( exist.fileExist() );
FileStatus notExist( mFileNameNotExist );
CPPUNIT_ASSERT( ! notExist.fileExist() );
}
void testFileModifyDateBasic()
{
FILETIME fileTime;
GetSystemTimeAsFileTime( &fileTime );
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT_NO_THROW( exist.getFileModifyDate() );
CPPUNIT_ASSERT_NO_THROW( exist.setFileModifyDate( &fileTime ) );
FileStatus notExist( mFileNameNotExist );
CPPUNIT_ASSERT_THROW( notExist.getFileModifyDate(), FileStatusError );
CPPUNIT_ASSERT_THROW( notExist.setFileModifyDate( &fileTime ), FileStatusError );
}
void testFileModifyDateEqual()
{
FILETIME fileTime;
GetSystemTimeAsFileTime( &fileTime );
FileStatus exist( mFileNameExist );
CPPUNIT_ASSERT_NO_THROW( exist.setFileModifyDate( &fileTime ) );
FILETIME get = exist.getFileModifyDate();
CPPUNIT_ASSERT( CompareFileTime( &get, &fileTime ) == 0 );
}
};
CPPUNIT_TEST_SUITE_REGISTRATION( MyTestCase );
int main()
{
CPPUNIT_NS::TestResult r;
CPPUNIT_NS::TestResultCollector result;
r.addListener( &result );
CPPUNIT_NS::TestFactoryRegistry::getRegistry().makeTest()->run( &r );
CPPUNIT_NS::TextOutputter out( &result, std::cout );
out.write();
return 0;
}
这里的
CPPUNIT_TEST_SUITE( MyTestCase );
CPPUNIT_TEST( testCtorAndGetName );
CPPUNIT_TEST( testGetFileSize );
CPPUNIT_TEST( testFileExist );
CPPUNIT_TEST( testFileModifyDateBasic );
CPPUNIT_TEST( testFileModifyDateEqual );
CPPUNIT_TEST_SUITE_END();
最重要的内容其实是定义了一个函数suite，这个函数返回了一个包含了所有CPPUNIT_TEST定义的测试用例的一个测试集。CPPUNIT_TEST_SUITE_REGISTRATION通过静态注册把这个测试集注册到全局的测试树中，最后通过CPPUNIT_NS::TestFactoryRegistry::getRegistry(). makeTest()生成一个包含所有测试用例的测试并且运行。具体的内部运行机制请参考CppUnit代码简介。
VII. 小节
这篇文章简要的介绍了CppUnit和测试驱动开发的基本概念，虽然CppUnit还有很多别的功能，譬如说基于GUI的测试环境以及和编译器Post Build相连接的测试输出，以及对于测试系统的扩展等，但是基本上掌握了本文中的内容就可以进行测试驱动的开发了。
此外，测试驱动开发还可以检验需求的错误。其实我选用GetFileTime和 SetFileTime作为例子是因为，有些系统上，SetFileTime所设置的时间是有一定的精度的，譬如说按秒，按天，...，因此你设置了一个时间后，可能get回来的时间和它不同。这其实是一个需求的错误。当然由于我的系统上没有这个问题，所以我也就不无病呻吟了。具体可以参考MSDN中对于这两个函数的介绍。
文章来源于领测软件测试网 https://www.ltesting.net/
