As of v0.18.1 I can use `test_bitcoin-qt -platform cocoa` to run GUI tests; this opens and closes a regtest GUI a bunch of times.

As of master (6e4f6553913978fcdddba30e0bb6f97edcb12e80) it seems to ignore the `-platform cocoa` and just run the test as with `minimal`.

As seen on macOS 10.14.6. Git bisect blames a2714a5c69f0b0506689af04c3e785f71ee0915d in #16578 `Do not pass in command line arguments to QApplication` (@achow101, @ryanofsky)
EditAddressDialog* dialog,
        const QString& label, const QString& address, QString expected_msg)
{
    QString warning_text;
    dialog->findChild<QLineEdit*>("labelEdit")->setText(label);
    dialog->findChild<QValidatedLineEdit*>("addressEdit")->setText(address);
    ConfirmMessage(&warning_text, 5);
    dialog->accept();
    QCOMPARE(warning_text, expected_msg);
}
/**
 * Test adding various send addresses to the address book.
 *
 * There are three cases tested:
 *
 *   - new_address: a new address which should add as a send address successfully.
 *   - existing_s_address: an existing sending address which won't add successfully.
 *   - existing_r_address: an existing receiving address which won't add successfully.
 *
 * In each case, verify the resulting state of the address book and optionally
 * the warning message presented to the user.
 */
void TestAddAddressesToSendBook()