Testing

1
Testing

• Unit Testing
• Testing of a unit of code, usually a class
• Integration Testing
• Testing of a module of code (e.g. a package)
• Application Testing
• Testing the code as the user would see it (black
  box)

2
CppUnit

• Automated regression testing framework
• Part of XUnit family
• JUnit
• VBUnit
• NUnit
• Many others

3
CppUnit Testing

• Each class is tested while developed
• Create tests first
• Start with simplest that works
• Incrementally add code while testing
• Tests serve as benchmark
• Optimize and refactor without worry

4
Testcase Design

• You cant test a program completely
• Equivalence classes
• They all test the same thing
• If one test catches a bug, the other probably
  will too
• If one test doesnt catch a bug, the others
  probably wont either

5
Equivalence Classes
From Testing Computer Software. Kaner, Falk,
and Nguyen. 1999.
6
Common Software Errors

• Error Handling
• Error detection/prevention/recovery
• Boundary-Related Errors
• Numeric boundaries
• Off-by-one errors
• Calculation Errors
• Overflow and underflow
• Truncation and round-off errors
• Incorrect conversions

7
Common Software Errors

• Initial and Later States
• Failure to initialize data
• Failure to initialize loop-control item
• Failure to initialize pointer
• Load Conditions
• Required resource not available
• No large memory areas available
• Source, Version, and ID Control
• Old bugs reappear
• Manufactured disks contain wrong code or data

8
Creating a Test

• Subclass the TestCase class
• Implement test functions
• Run the test using a TestRunner
• Group multiple TestCases using TestSuite
• All of this is made much easier with CppUnit
  Helper Macros

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Example (header file)

• include ltcppunit/extensions/HelperMacros.hgt
• class MyTestCase public CPPUNIT_NSTestFixtur
  e CPPUNIT_TEST_SUITE( MyTestCase )
  CPPUNIT_TEST( testOne ) CPPUNIT_TEST( testTwo
  ) CPPUNIT_TEST_SUITE_END()protected void
  testOne() void testTwo()

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Example (implementation file)

• CPPUNIT_TEST_SUITE_REGISTRATION(MyTestCase)voi
  d MyTestCasetestOne() // test code goes
  herevoid MytestCasetestTwo() // test
  code goes here

11
Example (driver)

• include ltcppunit/ui/text/TestRunner.hgtinclude
  ltcppunit/extensions/TestFactoryRegistry.hgtint
  main( int argc, char argv )
  CPPUNIT_NSTextUiTestRunner runner
  runner.addTest( CPPUNIT_NSTestFactoryRegistry
  getRegistry().makeTest() ) return
  runner.run() ? 0 1

12
Checking Results

• CPPUNIT_ASSERT(condition)
• CPPUNIT_ASSERT_MESSAGE(message, condition)
• CPPUNIT_ASSERT_EQUAL(expected, actual)
• CPPUNIT_ASSERT_EQUAL_MESSAGE(message, expected,
  actual)
• CPPUNIT_ASSERT_DOUBLES_EQUAL(expected, actual,
  delta)
• CPPUNIT_FAIL(message)

13
Checking Results Example

• void testEquality() Money a(1, 50) Money
  b(1, 50) CPPUNIT_ASSERT(a b)

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Test Fixture

• setUp()
• Initialize member variables common to all tests
• Called once before each test
• tearDown()
• Release resources
• Called once after each test

15

• class ShoppingCartTest() public
  ShoppingCart m_cart Product
  m_book void setUp() m_cart new
  ShoppingCart() m_book new Product(Unit
  Test) m_cart-gtAddItem(book) void
  tearDown() delete cart delete book
  void testAddItem() void
  testRemoveItem()

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Missing Resource

• Implementation requires a resource that is not
  available
• Create stub that returns anticipated results
• Class TextFilepublic bool
  m_isFileAvailable bool OpenFile(const char
  filename) return m_isFileAvailable

17
Handling New Bugs

• If a bug is found
• Add it to the test suite
• Then correct bug

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UCS Configuration

• .cshrc
• setenv LD_LIBRARY_PATH /pkgs2/cppunit-1.10.2/lib
• .bashrc
• export LD_LIBRARY_PATH/pkgs2/cppunit-1.10.2/lib

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Resources

• http//cppunit.sourceforge.net/doc/1.8.0/cppunit_c
  ookbook.html
• /pkgs2/cppunit-1.10.2/include/cppunit
• TestAssert.h (and others)
• /pkgs2/cppunit-1.10.2/include/cppunit/extensions
• HelperMacros.h (and others)

20
Sample Class for Testing

• class Moneypublic // Creates new
  initialized Money object // dollars range 0,
  inf) // cents - range 0, 99 Money(int
  dollars, int cents) bool operator(const
  Money rhs) stdstring ToString() const