/*! \page money_example Money, a step by step example

\section Table of contents

  - \ref sec_setting_vc

  - \ref sec_setting_unix

  - \ref sec_running_test

  - \ref sec_adding_testfixture

  - \ref sec_first_tests

  - \ref sec_more_tests

  - \ref sec_credits

  The example explored in this article can be found in \c examples/Money/.

\section sec_setting_vc Setting up your project (VC++)

\subsection sec_install Compiling and installing CppUnit libaries

In the following document, $CPPUNIT is the directory where you unpacked %CppUnit:

$CPPUNIT/:

	include/

	lib/

	src/

		cppunit/

First, you need to compile %CppUnit libraries:

- Open the $CPPUNIT/src/CppUnitLibraries.dsw workspace in VC++.

- In the 'Build' menu, select 'Batch Build...'

- In the batch build dialog, select all projects and press the build button.

- The resulting libraries can be found in the $CPPUNIT/lib/ directory.

Once it is done, you need to tell VC++ where are the includes and libraries

to use them in other projects. Open the 'Tools/Options...' dialog, and in the

'Directories' tab, select 'include files' in the combo. Add a new entry that

points to $CPPUNIT/include/. Change to 'libraries files' in the combo and 

add a new entry for $CPPUNIT/lib/. Repeat the process with 'source files' 

and add $CPPUNIT/src/cppunit/.

\subsection sec_getting_started Getting started

Creates a new console application ('a simple application' template will do).

Let's link %CppUnit library to our project. In the project settings:

- In tab 'C++', combo 'Code generation', set the combo to 'Multithreaded DLL'

for the release configuration, and 'Debug Multithreaded DLL' for the debug

configure,

- In tab 'C++', combo 'C++ langage', for All Configurations, check 

'enable Run-Time Type Information (RTTI)',

- In tab 'Link', in the 'Object/library modules' field, add cppunitd.lib for

the debug configuration, and cppunit.lib for the release configuration.

We're done !

\section sec_setting_unix Setting up your project (Unix)

We'll use \c autoconf and \c automake to make it simple to 

create our build environment. Create a directory somewhere to 

hold the code we're going to build. Create \c configure.in and 

\c Makefile.am in that directory to get started.

<tt>configure.in</tt>

\verbatim

dnl Process this file with autoconf to produce a configure script.

AC_INIT(Makefile.am)

AM_INIT_AUTOMAKE(money,0.1)

AM_PATH_CPPUNIT(1.9.6)

AC_PROG_CXX

AC_PROG_CC

AC_PROG_INSTALL

AC_OUTPUT(Makefile)\endverbatim

<tt>Makefile.am</tt>

\verbatim

# Rules for the test code (use `make check` to execute)

TESTS = MoneyApp

check_PROGRAMS = $(TESTS)

MoneyApp_SOURCES = Money.h MoneyTest.h MoneyTest.cpp MoneyApp.cpp

MoneyApp_CXXFLAGS = $(CPPUNIT_CFLAGS)

MoneyApp_LDFLAGS = $(CPPUNIT_LIBS) -ldl\endverbatim

\section sec_running_test Running our tests

We have a main that doesn't do anything. Let's start by adding the mechanics

to run our tests (remember, test before you code ;-) ). For this example, 

we will use a TextTestRunner with the CompilerOutputter for post-build 

testing:

<tt>MoneyApp.cpp</tt>

\code

#include "stdafx.h"

#include <cppunit/CompilerOutputter.h>

#include <cppunit/extensions/TestFactoryRegistry.h>

#include <cppunit/ui/text/TestRunner.h>

int main(int argc, char* argv[])

{

  // Get the top level suite from the registry

  CppUnit::Test *suite = CppUnit::TestFactoryRegistry::getRegistry().makeTest();

  // Adds the test to the list of test to run

  CppUnit::TextUi::TestRunner runner;

  runner.addTest( suite );

  // Change the default outputter to a compiler error format outputter

  runner.setOutputter( new CppUnit::CompilerOutputter( &runner.result(),

                                                       std::cerr ) );

  // Run the tests.

  bool wasSucessful = runner.run();

  // Return error code 1 if the one of test failed.

  return wasSucessful ? 0 : 1;

}\endcode

  VC++: Compile and run (Ctrl+F5).

  Unix: First build. Since we don't have all the file yet, let's create them

  and build our application for the first time:

\verbatim

touch Money.h MoneyTest.h MoneyTest.cpp

aclocal -I /usr/local/share/aclocal

autoconf

automake -a

touch NEWS README AUTHORS ChangeLog # To make automake happy

./configure

make check\endverbatim

  Our application will report that everything

is fine and no test were run. So let's add some tests...

\subsection sec_post_build Setting up automated post-build testing (VC++)

What does post-build testing means? It means that each time you compile,

the test are automatically run when the build finish. This is very

useful, if you compile often you can know that you just 'broke' something,

or that everything is still working fine.

Let's adds that to our project, In the project settings, in the 

'post-build step' tab:

- Select 'All configurations' (upper left combo)

- In the 'Post-build description', enter 'Unit testing...'

- In 'post-build command(s)', add a new line: <tt>\$(TargetPath)</tt>

<tt>\$(TargetPath)</tt> expands into the name of your application:

Debug\\MoneyApp.exe in debug configuration and Release\\MoneyApp.exe in release

configuration.

What we are doing is say to VC++ to run our application for each build. 

Notices the last line of \c main(), it returns a different error code, 

depending on weither or not a test failed. If the code returned by

an application is not 0 in post-build step, it tell VC++ that the build

step failed.

Compile. Notice that the application's output is now in the build window.

How convenient!

  (Unix: tips to integrate make check into various IDE?)

\section sec_adding_testfixture Adding the TestFixture

For this example, we are going to write a simple money class. Money

has an amount and a currency. Let's begin by creating a fixture where

we can put our tests, and add single test to test Money constructor:

<tt>MoneyTest.h:</tt>

\code

#ifndef MONEYTEST_H

#define MONEYTEST_H

#include <cppunit/extensions/HelperMacros.h>

class MoneyTest : public CppUnit::TestFixture

{

  CPPUNIT_TEST_SUITE( MoneyTest );

  CPPUNIT_TEST( testConstructor );

  CPPUNIT_TEST_SUITE_END();

public:

  void setUp();

  void tearDown();

  void testConstructor();

};

#endif  // MONEYTEST_H\endcode

- CPPUNIT_TEST_SUITE declares that our Fixture's test suite.

- CPPUNIT_TEST adds a test to our test suite. The test is implemented 

by a method named testConstructor().

- setUp() and tearDown() are use to setUp/tearDown some fixtures. We are

not using any for now.

<tt>MoneyTest.cpp</tt>

\code

#include "stdafx.h"

#include "MoneyTest.h"

// Registers the fixture into the 'registry'

CPPUNIT_TEST_SUITE_REGISTRATION( MoneyTest );

void 

MoneyTest::setUp()

{

}

void 

MoneyTest::tearDown()

{

}

void 

MoneyTest::testConstructor()

{

  CPPUNIT_FAIL( "not implemented" );

}

\endcode

Compile. As expected, it reports that a test failed. Press the \c F4 key

(Go to next Error). VC++ jump right to our failed assertion CPPUNIT_FAIL.

We can not ask better in term of integration!

\verbatim

Compiling...

MoneyTest.cpp

Linking...

Unit testing...

.F

G:\prg\vc\Lib\cppunit\examples\money\MoneyTest.cpp(26):Assertion

Test name: MoneyTest.testConstructor

not implemented

Failures !!!

Run: 1   Failure total: 1   Failures: 1   Errors: 0

Error executing d:\winnt\system32\cmd.exe.

moneyappd.exe - 1 error(s), 0 warning(s)

\endverbatim

Well, we have everything set up, let's start doing some real testing.

\section sec_first_tests Our first tests

Let's write our first real test. A test is usually decomposed in three parts:

- setting up datas used by the test

- doing some processing based on those datas

- checking the result of the processing

\code

void 

MoneyTest::testConstructor()

{

  // Set up

  const std::string currencyFF( "FF" );

  const double longNumber = 12345678.90123;

  // Process

  Money money( longNumber, currencyFF );

  // Check

  CPPUNIT_ASSERT_EQUAL( longNumber, money.getAmount() );

  CPPUNIT_ASSERT_EQUAL( currencyFF, money.getCurrency() );

}\endcode

Well, we finally have a good start of what our Money class will

look like. Let's start implementing...

<tt>Money.h</tt>

\code

#ifndef MONEY_H

#define MONEY_H

#include <string>

class Money

{

public:

  Money( double amount, std::string currency )

    : m_amount( amount )

    , m_currency( currency )

  {

  }

  double getAmount() const

  {

    return m_amount;

  }

  std::string getCurrency() const

  {

    return m_currency;

  }

private:

  double m_amount;

  std::string m_currency;

};

#endif\endcode

Include <tt>Money.h</tt> in MoneyTest.cpp and compile.

Hum, an assertion failed! Press F4, and we jump to the assertion

that checks the currency of the constructed money object. The report

indicates that string is not equal to expected value. There is only

two ways for this to happen: the member was badly initialized or we

returned the wrong value. After a quick check, we find out it is the former.

Let's fix that:

<tt>Money.h</tt>

\code

  Money( double amount, std::string currency )

    : m_amount( amount )

    , m_currency( currency )

  {

  }\endcode

Compile. Our test finally pass!

Let's add some functionnality to our Money class.

\section sec_more_tests Adding more tests

\subsection sec_equal Testing for equality

  We want to check if to Money object are equal. Let's start by adding

a new test to the suite, then add our method:

<tt>MoneyTest.h</tt>

\code

  CPPUNIT_TEST_SUITE( MoneyTest );

  CPPUNIT_TEST( testConstructor );

  CPPUNIT_TEST( testEqual );

  CPPUNIT_TEST_SUITE_END();

public:

  ...

  void testEqual();

\endcode

<tt>MoneyTest.cpp</tt>

\code

void

MoneyTest::testEqual()

{

  // Set up

  const Money money123FF( 123, "FF" );

  const Money money123USD( 123, "USD" );

  const Money money12FF( 12, "FF" );

  const Money money12USD( 12, "USD" );

  // Process & Check

  CPPUNIT_ASSERT( money123FF == money123FF );     // ==

  CPPUNIT_ASSERT( money12FF != money123FF );      // != amount

  CPPUNIT_ASSERT( money123USD != money123FF );    // != currency

  CPPUNIT_ASSERT( money12USD != money123FF );     // != currency and != amount

}\endcode

  Let's implements \c operator \c == and \c operator \c != in Money.h:

<tt>Money.h</tt>

\code

class Money

{

public:

...

  bool operator ==( const Money &other ) const

  {

    return m_amount == other.m_amount  &&  

           m_currency == other.m_currency;

  }

  bool operator !=( const Money &other ) const

  {

    return (*this == other);

  }

};

\endcode

  Compile, run... Ooops... Press F4, it seems we're having trouble 

with \c operator \c !=. Let's fix that:

\code

  bool operator !=( const Money &other ) const

  {

    return !(*this == other);

  }\endcode

Compile, run. Finally got it working!

\subsection sec_opadd Adding moneys

  Let's add our test 'testAdd' to MoneyTest. You know the routine...

<tt>MoneyTest.cpp</tt>

\code

void 

MoneyTest::testAdd()

{

  // Set up

  const Money money12FF( 12, "FF" );

  const Money expectedMoney( 135, "FF" );

  // Process

  Money money( 123, "FF" );

  money += money12FF;

  // Check

  CPPUNIT_ASSERT( expectedMoney == money );           // add works

  CPPUNIT_ASSERT( &money == &(money += money12FF) );  // add returns ref. on 'this'.

}\endcode

  While writing that test case, you ask yourself, what is the result of

adding money of currencies. Obviously this is an error and it should be

reported, say let throw an exception, say \c IncompatibleMoneyError, 

when the currencies are not equal. We will write another test case

for this later. For now let get our testAdd() case working:

<tt>Money.h</tt>

\code

class Money

{

public:

...

  Money &operator +=( const Money &other )

  {

    m_amount += other.m_amount;

    return *this;

  }

}; \endcode

Compile, run. Miracle, everything is fine! Just to be sure the test is indeed

working, in the above code, change \c m_amount \c += to \c -=. Build and 

check that it fails (always be suspicious of test that work the first 

time: you may have forgotten to add it to the suite for example)! 

Change the code back so that all the tests are working.

  Let's the incompatible money test case before we forget about it...

That test case expect an \c IncompatibleMoneyError exception to be thrown. 

%CppUnit can test that for us, you need to specify that the test case

expect an exception when you add it to the suite:

<tt>MoneyTest.h</tt>

\code

class MoneyTest : public CppUnit::TestFixture

{

  CPPUNIT_TEST_SUITE( MoneyTest );

  CPPUNIT_TEST( testConstructor );

  CPPUNIT_TEST( testEqual );

  CPPUNIT_TEST( testAdd );

  CPPUNIT_TEST_EXCEPTION( testAddThrow, IncompatibleMoneyError );

  CPPUNIT_TEST_SUITE_END();

public:

  ...

  void testAddThrow();

};\endcode

By convention, you end the name of such tests with \c 'Throw', that way, you

know that the test expect an exception to be thrown. Let's write our test case:

<tt>MoneyTest.cpp</tt>

\code

void 

MoneyTest::testAddThrow()

{

  // Set up

  const Money money123FF( 123, "FF" );

  // Process

  Money money( 123, "USD" );

  money += money123FF;        // should throw an exception

}

\endcode

  Compile... Ooops, forgot to declare the exception class. Let's do that:

<tt>Money.h</tt>

\code

#include <string>

#include <stdexcept>

class IncompatibleMoneyError : public std::runtime_error

{

public:

  IncompatibleMoneyError() : runtime_error( "Incompatible moneys" )

  {

  }

};

\endcode

  Compile. As expected testAddThrow() fail... Let's fix that:

<tt>Money.h</tt>

\code

  Money &operator +=( const Money &other )

  {

    if ( m_currency != other.m_currency )

      throw IncompatibleMoneyError();

    m_amount += other.m_amount;

    return *this;

  }\endcode

  Compile. Our test finaly passes!

  TODO:

- How to use CPPUNIT_ASSERT_EQUALS with Money

- Copy constructor/Assignment operator

- Introducing fixtures

- ?

\section sec_credits Credits

This article was written by Baptiste Lepilleur. Unix configuration & set up 

by Phil Verghese. Inspired from many others (JUnit, Phil's cookbook...), 

and all the newbies around that keep asking me for the 

'Hello world' example ;-)

*/