Have Geek Brain

Qtestlib: QNetworkRequest failed

I would like to test an asynchronous request to a web server. For this, I create a simple unittest to quickly try a few lines of code:

void AsynchronousCall::testGet()
{
    QNetworkAccessManager *nam =  new QNetworkAccessManager(this);

    QUrl url("http://myownhttpserver.org");
    QNetworkRequest req(url);


    this->connect(nam, SIGNAL(finished(QNetworkReply*)), this, SLOT(reqFinished(QNetworkReply *)));
    QNetworkReply *rep = nam->get(req);

}

void AsynchronousCall::reqFinished(QNetworkReply *rep)
{
    qDebug() << rep->readAll();
    qDebug() << "finshed";
}

The problem is that reqFinished () is never reached. If I had a simple QEventLoop and an .exec () loop right after nam-> get (req); the request is being executed.

Any hint? Should I use loop.exec () in my unittests?

+2


a source to share


1 answer


If you want to test asynchronous behavior, you need to use QEventLoop or another class with similar functionality. I suggest you write a helper method like this:

bool waitForSignal(QObject *sender, const char *signal, int timeout = 1000) {
    QEventLoop loop;
    QTimer timer;
    timer.setInterval(timeout);
    timer.setSingleShot(true);

    loop.connect(sender, signal, SLOT(quit()));
    loop.connect(&timer, SIGNAL(timeout()), SLOT(quit()));
    timer.start();
    loop.exec();

    return timer.isActive();
}

Then you can use it in your unit tests like this:



void AsynchronousCall::testGet()
{
    QNetworkAccessManager *nam =  new QNetworkAccessManager(this);

    QUrl url("http://myownhttpserver.org");
    QNetworkRequest req(url);


    this->connect(nam, SIGNAL(finished(QNetworkReply*)), this, SLOT(reqFinished(QNetworkReply *)));
    QNetworkReply *rep = nam->get(req);
    QVERIFY(waitForSignal(nam, SIGNAL(finished(QNetworkReply*)), 5000));
}

There are other problems in your test:

  • Tests that depend on network connectivity do not need to be modular. You want your unit tests to fire up quickly, which is impossible to achieve with network connections.
  • Your test doesn't actually test anything: it just puts some information into the debug console. You must define expectations and test them using the QVERIFY and QCOMPARE macros.
  • QTest sucks IMHO. If you're building a testbase from scratch, start using gtest + gmock instead.
+13


a source






More articles:


All Articles