Ideally the tests wouldn't touch the default data directory. Both the core unit tests and the functional tests do this correctly. However,  `src/qt/test/test_bitcoin-qt` seems to create an empty `~/.bitcoin` directory if it doesn't exist yet.
Instead, it should set up a temporary data directory like the other tests.
#if defined(QT_QPA_PLATFORM_MINIMAL)
Q_IMPORT_PLUGIN(QMinimalIntegrationPlugin);
#endif
#if defined(QT_QPA_PLATFORM_XCB)
Q_IMPORT_PLUGIN(QXcbIntegrationPlugin);
#elif defined(QT_QPA_PLATFORM_WINDOWS)
Q_IMPORT_PLUGIN(QWindowsIntegrationPlugin);
#elif defined(QT_QPA_PLATFORM_COCOA)
Q_IMPORT_PLUGIN(QCocoaIntegrationPlugin);
#endif
#endif
#endif
extern void noui_connect();
int main(int argc, char *argv[])
{
    SetupEnvironment();
    SetupNetworking();
    SelectParams(CBaseChainParams::MAIN);
    noui_connect();
    bool fInvalid = false;
    
    
    
    #if defined(WIN32)
        _putenv_s("QT_QPA_PLATFORM", "minimal");
    #else
        setenv("QT_QPA_PLATFORM", "minimal", 0);
    #endif