CppUnit :无法编写测试用例

Question

我用cppUnit写了testBMath.cc码。我能够为前三个函数编写测试用例，它们是加、减和乘。但我无法为Divide和Swap.I编写测试用例，我不知道如何在测试用例中处理被零除法，以及如何检查在cppUnit测试用例中是否交换了数字。

testMath.h

#ifndef TEST_MATH_H__
    #define TEST_MATH_H__
    class testMath
    {
    public:
    int Addition(int x, int y);
    int Multiply(int x, int y);
    int Subtraction(int x, int y);
    int Division(int x, int y);
    void swap(int &x, int &y);
    };
#endif

testMath.cc

    #include "testMath.h"

    int testMath::Addition(int x, int y)
    {
        return (x + y);
    }

    int testMath::Multiply(int x, int y)
    {
        return (x * y);
    }

    int testMath::Subtraction(int x, int y)
    {
        return (x - y);
    }

    int testMath::Division(int x, int y)
    {
       if( b == 0 )
    {
          throw "Division by zero condition!";
    }
       return (a/b);
    }

    void swap(int &a, int &b)
    {
      int temp;

      temp = b;
      b   = a;
      a   = temp;   
    }

testBMath.cc

    #include <iostream>
    #include <string>
    #include <list>
    #include "cppunit/TestCase.h"
    #include "cppunit/TestFixture.h"
    #include "cppunit/ui/text/TextTestRunner.h"
    #include "cppunit/extensions/HelperMacros.h"
    #include "cppunit/extensions/TestFactoryRegistry.h"
    #include "cppunit/TestResult.h"
    #include "cppunit/TestResultCollector.h"
    #include "cppunit/TestRunner.h"
    #include "cppunit/BriefTestProgressListener.h"
    #include "cppunit/CompilerOutputter.h"
    #include "netinet/in.h"

    #include "testMath.h"

    using namespace CppUnit;
    using namespace std;

    //-----------------------------------------------------------------------------
    class testBMath : public CppUnit::TestFixture
    {
    CPPUNIT_TEST_SUITE(testBMath);
    CPPUNIT_TEST(testAddition);
    CPPUNIT_TEST(testMultiply);
    CPPUNIT_TEST(testSubtraction);
    CPPUNIT_TEST(testDivision);
    CPPUNIT_TEST(testSwap);
    CPPUNIT_TEST_SUITE_END();

    public:
    void setUp(void);
    void tearDown(void);

    protected:
    void testAddition(void);
    void testMultiply(void);
    void testSubtraction(void);
    void testDivision(void);
    void testSwap(void);

    private:
    testMath *mTestObj;
    };

    //-----------------------------------------------------------------------------

    void testBMath::setUp(void)
    {
    mTestObj = new testMath();
    }

    void testBMath::testAddition(void)
    {
    CPPUNIT_ASSERT(5 == mTestObj->Addition(2,3));
    }

    void testBMath::testMultiply(void)
    {
    CPPUNIT_ASSERT(6 == mTestObj->Multiply(2,3));
    }
    void testBMath::testSubtraction(void)
    {
    CPPUNIT_ASSERT(2 == mTestObj->Subtraction(5,3));
    }

    void testBMath::testDivision(void)
    {
    CPPUNIT_ASSERT(6 == mTestObj->Division(12,2));
    //But for divide by zero how should I write
    }

    void testBMath::testSwap(void)
    {
    //How should I check for swap
    }

    void testBMath::tearDown(void)
    {
    delete mTestObj;
    }

    //-----------------------------------------------------------------------------
    CPPUNIT_TEST_SUITE_REGISTRATION( testBMath );

    int main(int argc, char* argv[])
    {
    // informs test-listener about testresults
    CPPUNIT_NS::TestResult testresult;

    // register listener for collecting the test-results
    CPPUNIT_NS::TestResultCollector collectedresults;
    testresult.addListener (&collectedresults);

    // register listener for per-test progress output
    CPPUNIT_NS::BriefTestProgressListener progress;

    testresult.addListener (&progress);

    // insert test-suite at test-runner by registry
    CPPUNIT_NS::TestRunner testrunner;

    testrunner.addTest (CPPUNIT_NS::TestFactoryRegistry::getRegistry().makeTest ());

    testrunner.run(testresult);

    // output results in compiler-format
    CPPUNIT_NS::CompilerOutputter compileroutputter(&collectedresults, std::cerr);

    compileroutputter.write ();

    // return 0 if tests were successful
    return collectedresults.wasSuccessful() ? 0 : 1;
    }

Answer 1

我的建议，将异常从const char*更改为更有意义的东西，比如std::runtime_error

int testMath::Division(int x, int y)
{
   if( b == 0 )
   {
      throw std::runtime_error("Division by zero condition!");
   }
   return (a/b);
}

比测试看上去更像是：

void testBMath::testDivision(void)
{
   CPPUNIT_ASSERT(6 == mTestObj->Division(12,2));
   CPPUNIT_ASSERT_THROW(mTestObj->Division(12,0), std::runtime_error);
}

void testBMath::testSwap(void)
{
   int x = 2;
   int y = 3;
   mTestObj->swap(x, y);
   CPPUNIT_ASSERT(x == 3 && y == 2);
}