Introduction to C-Unit test Framework (Cutest) Brian Nielsen Arne Skou

Transcription

1 Introduction to C-Unit test Framework (Cutest) Brian Nielsen Arne Skou {bnielsen

2 xunit principles Write test suite for each module in the program. All test can be executed (automatically) at any time. For each program modification all tests must be passed before the modification is regarded as complete - regression testing Test First implement later! Originally based on extreme Programming principles: Lightweight software development methodology by programmers for programmers Rapid feedback Assume simplicity Incremental change Embracing change Quality work

3 Concepts Assertion Expression that determines if a test fails The basic and smallest building-block Test Case A composition of concrete test procedures May contain several assertions and test for several test objectives E.g all test of a particular function Test Suite Collection of related test cases Can be executed in a single command

4 Cutest built-in Assertions Syntax Examples void CuAssert(CuTest* tc, char* message, int condition); void CuAssertTrue(CuTest* tc, int condition); void CuAssertStrEquals(CuTest* tc, char* expected, char* actual); void CuAssertIntEquals(CuTest* tc, int expected, int actual); void CuAssertPtrEquals(CuTest* tc, void* expected, void* actual); void CuAssertPtrNotNull(CuTest* tc, void* pointer); 1. CuAssertIntEquals(tc, 3, sqrt(9)); 2. CuAssertIntEquals(tc, rectangulartriangle, classifytriangle(13,12,6) ); 3. CuAssertDblEquals(tc,expectedContrib,actualContrib, 0.0); 4. char*argv[4]= {programname,"13","12","5"}; CuAssertStrEquals(tc, "Rectangular Triangle", checktriangle(4,argv)); Extend with own assertions!

5 Test Case Contains a sequence of concrete test procedures/steps An implementation of prototype void testcase(cutest* tc); void void TestTriangleRectangular(CuTest* tc){ CuAssertIntEquals(tc, rectangulartriangle, classifytriangle(13,12,5) ); }

6 Test Case Examples void void TestTriangleRectangular(CuTest* tc){ CuAssertIntEquals(tc, rectangulartriangle, classifytriangle(13,12,5) ); } void TestTriangle (CuTest* tc) { CuAssertIntEquals(tc, rectangulartriangle, classifytriangle(13,12,5) ); CuAssertIntEquals(tc, scalenetriangle, classifytriangle(15,10,5) ); CuAssertIntEquals(tc, equilateraltriangle, classifytriangle(int_max,int_max,int_max) CuAssertIntEquals(tc, isoscelestriangle, classifytriangle(1,1,2) ); CuAssertIntEquals(tc, invalidtriangle, classifytriangle(100,0,10) ); CuAssertIntEquals(tc, invalidtriangle, classifytriangle(100,50,-1) ); } void TestIRSValid(CuTest* tc) { #define nopaymentsvalid 5 double actualcontrib; double payments[nopaymentsvalid]= {1000.0, , 0.1, 42, 50000}; const double expectedcontrib = ; actualcontrib = iracontribution( ,'s',payments,nopaymentsvalid ); } CuAssertDblEquals(tc,expectedContrib,actualContrib, 0.0);

7 Test suite Collection of tests in a logical unit Contains Test cases Other test suites (ie. Hierarchical: function, module, application) Example: Execute CuSuite* suite = CuSuiteNew(); SUITE_ADD_TEST(suite, TestIRSValid); SUITE_ADD_TEST( CuSuite* allsuite = CuSuiteNew(); CuSuiteAddSuite(allSuite, suite); CuSuiteRun(suite);

8 Results Textually: borg [~/Undervisning/MTV/cutest/TestTriangle]:./testTriangle...F... There was 1 failure: 1) TestTriangleRectangularDemoFail: testtriangle.c:32: expected <1> but was <4>!!!FAILURES!!! Runs: 29 Passes: 28 Fails: 1 Java Unit (JUNIT) XML Test Report->??

9 Advice Use xunit to store and maintain all the small tests that you write anyway Write tests instead of playing with debugger and printf tests can be automatically repeated Keep test code in a separate directory Keep both tests-sources and implemenationsource in CVS Design and program for testability Directly applicable to Pure function libraries API (With some footwork also user interfaces, network-, web-, and database applications)

10 Evaluation Positively: Simple and functional Open Source Offers an easy, systematic, and comprehensive way of organizing and executing tests Automatic execution (automated regression testing) Software industry are adopting xunit frame works BUT: No magic developer writes tests himself in (low level)development language. Simple Requires extensions: CuAssert Test report generation MANY different versions for C/C++ available Your Experience Appreciated!!