Running Multiple Unit Tests

Qt Creator supports creating a unit test project but the Qt documentation only describes running a single test. To run multiple tests you need to modify your main function to create an instance of each test object and then call qExec on it. Easy enough, but when you start creating lots of tests it's easy to forget to add the necessary code. I decided to simplify this process and came up with a small header file that you can use to make running multiple tests a breeze.

The code for the header, AutoTest.h can be found below. To use it, simply:

1. Add a #include "AutoTest.h" to all your QObject-derived test headers.
2. Add DECLARE_TEST(YourTestClassName) below your class definition.
3. Change your main.cpp to look like this:
   
   #include "AutoTest.h"
   
   TEST_MAIN
   

Easy. If you still need to supply your own main function (you might have other initialization code in here) then you can run all the tests with the following line of code:

AutoTest::run(argv, argc);

This function will return 0 if all the tests passed.

The source for AutoTest.h:

#ifndef AUTOTEST_H

#define AUTOTEST_H

#include <QTest>

#include <QList>

#include <QString>

#include <QSharedPointer>

namespace AutoTest

{

typedef QList<QObject*> TestList;

inline TestList& testList()

{

static TestList list;

return list;

}

inline bool findObject(QObject* object)

{

TestList& list = testList();

if (list.contains(object))

{

return true;

}

foreach (QObject* test, list)

{

if (test->objectName() == object->objectName())

{

return true;

}

}

return false;

}

inline void addTest(QObject* object)

{

TestList& list = testList();

if (!findObject(object))

{

list.append(object);

}

}

inline int run(int argc, char *argv[])

{

int ret = 0;

foreach (QObject* test, testList())

{

ret += QTest::qExec(test, argc, argv);

}

return ret;

}

}

template <class T>

class Test

{

public:

QSharedPointer<T> child;

Test(const QString& name) : child(new T)

{

child->setObjectName(name);

AutoTest::addTest(child.data());

}

};

#define DECLARE_TEST(className) static Test<className> t(#className);

#define TEST_MAIN \

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

{ \

return AutoTest::run(argc, argv); \

}

#endif // AUTOTEST_H

A typical test class header would look something like this:

#ifndef FOOTESTS_H

#define FOOTESTS_H

#include "AutoTest.h"

class FooTests : public QObject

{

Q_OBJECT

private slots:

void initTestCase();

void test1();

void test2();

void cleanupTestCase();

};

DECLARE_TEST(FooTests)

#endif // FOOTESTS_H

Apologies for the formatting - haven't worked out how to post decent looking code using blogger yet.