使用 gmock 依赖 QApplication 的测试功能

Question

我想测试一种使用

获取主屏幕屏幕尺寸的方法

void MouseMapper::getScreenProperties() {
    QDesktopWidget *widget = QApplication::desktop();
    QRect screenGeometry = widget->screenGeometry(widget->primaryScreen());
    _screenHeight = screenGeometry.height();
    _screenWidth = screenGeometry.width();
}

这可以正常工作。但是当我尝试使用 gmock 来测试它时

TEST(AMouseMapper, GetsTheScreenSize) {
    MouseMapper mouse;
    mouse.getScreenProperties();
    //I know these hardcodes values don't always apply,
    //thats not the point here
    ASSERT_EQ(1900, mouse.getScreenWidth());
    ASSERT_EQ(1200, mouse.getScreenHeight());
}

和

#include "gmock/gmock.h"

int main(int argc, char** argv) {
    testing::InitGoogleMock(&argc, argv);
    return RUN_ALL_TESTS();
}

我得到一个错误，因为我没有构造一个 QApplication，这是正确的。 所以当我尝试

#include "gmock/gmock.h"
#include <QApplication>

int main(int argc, char** argv) {
    testing::InitGoogleMock(&argc, argv);
    QApplication app(argc,argv);
    app.exec();
    return RUN_ALL_TESTS();
}

我得到同样的错误。当我尝试直接在测试函数中构造 QApplication（如 this answer 中所建议的那样）时，也会发生测试崩溃，因为 argc 和 argv 不正确或其他原因

TEST(AMouseMapper, GetsTheScreenSize) {
    char  arg0[] = "programName";
    char* argv[] = { &arg0[0], NULL };
    int   argc   = (int)(sizeof(argv) / sizeof(argv[0])) - 1;
    QApplication app(argc,&argv[0]);
    app.exec();
    MouseMapper mouse;
    mouse.getScreenProperties();
    ASSERT_EQ(1900, mouse.getScreenWidth()); //I know that these hardcoded values don't always apply
    ASSERT_EQ(1200, mouse.getScreenHeight());
}

Valgrind 然后给了我

==7093== Conditional jump or move depends on uninitialised value(s)
==7093==    at 0x102E437A: ??? (in /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0.2400.25)
==7093==    by 0x7EA2473: ??? (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.0)
==7093==    by 0x7EBC056: g_signal_emit_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.0)
==7093==    by 0x7EBCEF9: g_signal_emit_by_name (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.0)
==7093==    by 0x7EA9BDA: g_object_set_valist (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.0)
==7093==    by 0x7EAA46B: g_object_set (in /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0.4200.0)
==7093==    by 0x5EB0BB5: ??? (in /home/elmewo/Libraries/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5.3.2)
==7093==    by 0x5E2D23E: QStyleFactory::create(QString const&) (in /home/elmewo/Libraries/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5.3.2)
==7093==    by 0x5DC9B4A: QApplication::style() (in /home/elmewo/Libraries/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5.3.2)
==7093==    by 0x5DCA51C: QApplicationPrivate::initialize() (in /home/elmewo/Libraries/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5.3.2)
==7093==    by 0x5DCA56F: QApplicationPrivate::construct() (in /home/elmewo/Libraries/Qt/5.3/gcc_64/lib/libQt5Widgets.so.5.3.2)
==7093==    by 0x47B10E: AMouseMapper_GetsTheScreenSize_Test::TestBody() (MouseMapperTest.cpp:18)

我不知道我能在这里做什么。任何人都可以帮忙吗？

P.s.：我不想在这里使用 QTest。 :)

Answer 1

我们使用以下方法：

int main(int argc, char** argv)
{
    TestCoreApp app(argc, argv);
    ...
    app.exec();
}

在TestCoreApp的构造函数中：

TestCoreApp::TestCoreApp(int& argc, char** argv)
    : QCoreApplication(argc, argv)
{
    InitGMockAndGTest(argc, argv);
}

初始化函数：

void TestCoreApp::InitGMockAndGTest(int& argc, char** argv) const
{
    InitGoogleMock(&argc, argv);
    InitGoogleTest(&argc, argv);
}

您的 GoogleMockInit 在 QCoreApplication 初始化之前启动。

testing::InitGoogleMock(&argc, argv);
QApplication app(argc,argv);