fix(ci): run Qt tests headless in Docker/CI

Use QCoreApplication for the race test, set QT_QPA_PLATFORM=offscreen
and QT_MEDIA_BACKEND=ffmpeg for playback tests, and export the same vars
in CI before ctest to avoid subprocess aborts without a display.

.github/workflows/build.yml

@@ -35,6 +35,8 @@ jobs:
                 qt6-multimedia-ffmpeg
               cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
               cmake --build build -j"$(nproc)"
+              export QT_QPA_PLATFORM=offscreen
+              export QT_MEDIA_BACKEND=ffmpeg
               ctest --test-dir build --output-on-failure
               "$(/usr/lib/qt6/bin/qtpaths6 --query QT_INSTALL_BINS)/qmllint" src/qml/Main.qml src/qml/components/*.qml src/qml/theme/BearTheme.qml
             '

tests/CMakeLists.txt

@@ -1,5 +1,10 @@
 find_package(Qt6 REQUIRED COMPONENTS Test)
 
+set(BEARWAVE_TEST_ENV
+    QT_QPA_PLATFORM=offscreen
+    QT_MEDIA_BACKEND=ffmpeg
+)
+
 set(TEST_SOURCES
     radiobackend_playback_test.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/../src/radiobackend.cpp
@@ -25,6 +30,7 @@ target_link_libraries(radiobackend_playback_test PRIVATE
 )
 
 add_test(NAME radiobackend_playback_test COMMAND radiobackend_playback_test)
+set_tests_properties(radiobackend_playback_test PROPERTIES ENVIRONMENT "${BEARWAVE_TEST_ENV}")
 
 set(RACE_TEST_SOURCES
     radiobrowser_race_test.cpp
@@ -42,7 +48,7 @@ target_link_libraries(radiobrowser_race_test PRIVATE
     Qt6::Core
     Qt6::Network
     Qt6::Test
-    Qt6::Widgets
 )
 
 add_test(NAME radiobrowser_race_test COMMAND radiobrowser_race_test)
+set_tests_properties(radiobrowser_race_test PROPERTIES ENVIRONMENT "QT_QPA_PLATFORM=offscreen")

tests/radiobackend_playback_test.cpp

@@ -328,5 +328,14 @@ void RadioBackendPlaybackTest::manual_station_accepts_http_and_https()
     QCOMPARE(backend.stations().size(), 2);
 }
 
-QTEST_MAIN(RadioBackendPlaybackTest)
+int main(int argc, char *argv[])
+{
+    qputenv("QT_QPA_PLATFORM", "offscreen");
+    qputenv("QT_MEDIA_BACKEND", "ffmpeg");
+
+    QApplication app(argc, argv);
+    RadioBackendPlaybackTest test;
+    return QTest::qExec(&test, argc, argv);
+}
+
 #include "radiobackend_playback_test.moc"

tests/radiobrowser_race_test.cpp

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #include <QtTest>
-#include <QApplication>
+#include <QCoreApplication>
 #include <QSignalSpy>
 #include <QTemporaryDir>
 #include <QDir>
@@ -100,5 +100,11 @@ void RadioBrowserRaceTest::latest_request_wins_after_rapid_category_switch()
             || finalName == QStringLiteral("NL Station"));
 }
 
-QTEST_MAIN(RadioBrowserRaceTest)
+int main(int argc, char *argv[])
+{
+    QCoreApplication app(argc, argv);
+    RadioBrowserRaceTest test;
+    return QTest::qExec(&test, argc, argv);
+}
+
 #include "radiobrowser_race_test.moc"