test: add simple testcase for BoostrapNodeUpdater

This test just tries to connect to nodes.tox.chat and retrieve nodes.
The result is not checked yet.

cmake/Testing.cmake

@@ -23,7 +23,9 @@ auto_test(core toxid)
 auto_test(core toxstring)
 auto_test(chatlog textformatter)
 auto_test(net toxmedata)
+auto_test(net bsu)
 auto_test(persistence paths)
+
 if (UNIX)
   auto_test(platform posixsignalnotifier)
 endif()

test/net/bsu_test.cpp

@@ -0,0 +1,59 @@
+/*
+    Copyright © 2018 by The qTox Project Contributors
+
+    This file is part of qTox, a Qt-based graphical interface for Tox.
+
+    qTox is libre software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    qTox is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with qTox.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "src/net/bootstrapnodeupdater.h"
+
+#include <QNetworkProxy>
+#include <QSignalSpy>
+
+#include <QtTest/QtTest>
+
+// Needed to make this type known to Qt
+Q_DECLARE_METATYPE(QList<DhtServer>);
+
+class TestBootstrapNodesUpdater : public QObject
+{
+    Q_OBJECT
+public:
+    TestBootstrapNodesUpdater();
+private slots:
+    void testOnline();
+};
+
+TestBootstrapNodesUpdater::TestBootstrapNodesUpdater()
+{
+    qRegisterMetaType<QList<DhtServer>>("QList<DhtServer>");
+}
+
+void TestBootstrapNodesUpdater::testOnline()
+{
+    QNetworkProxy proxy{QNetworkProxy::ProxyType::NoProxy};
+    BootstrapNodeUpdater updater{proxy};
+    QSignalSpy spy(&updater, &BootstrapNodeUpdater::availableBootstrapNodes);
+
+    updater.requestBootstrapNodes();
+
+    spy.wait();
+    QCOMPARE(spy.count(), 1); // make sure the signal was emitted exactly one time
+    QList<DhtServer> result = qvariant_cast<QList<DhtServer>>(spy.at(0).at(0));
+    QVERIFY(result.size() > 0); // some data should be returned
+}
+
+QTEST_GUILESS_MAIN(TestBootstrapNodesUpdater)
+#include "bsu_test.moc"