test(app): add end-to-end scenarios against the real main window

Bundled registry/sample loading, edge selection populating the grouped
property panel, undoable title edit, solver + animation clock, and a
headless render smoke check.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/CMakeLists.txt

@@ -13,3 +13,9 @@ diag_add_test(tst_solver diagcore)
 diag_add_test(tst_json diagcore)
 diag_add_test(tst_undo diagscene)
 diag_add_test(tst_scene diagscene)
+
+qt_add_resources(TEST_RESOURCES ${CMAKE_SOURCE_DIR}/resources/resources.qrc)
+add_executable(tst_app tst_app.cpp ${TEST_RESOURCES})
+target_link_libraries(tst_app PRIVATE diagapp Qt6::Test)
+add_test(NAME tst_app COMMAND tst_app)
+set_tests_properties(tst_app PROPERTIES ENVIRONMENT "QT_QPA_PLATFORM=offscreen")

tests/tst_app.cpp

@@ -0,0 +1,138 @@
+// End-to-end scenarios against the real MainWindow with bundled resources
+// (registry config, SVGs, sample document), offscreen.
+
+#include "app/MainWindow.h"
+#include "app/PropertyPanel.h"
+#include "core/FlowSolver.h"
+#include "core/NetworkModel.h"
+#include "scene/DiagramScene.h"
+#include "scene/EdgeItem.h"
+#include "scene/NodeItem.h"
+
+#include <QComboBox>
+#include <QDoubleSpinBox>
+#include <QGroupBox>
+#include <QLineEdit>
+#include <QTest>
+#include <QUndoStack>
+
+using namespace diag;
+
+class TestApp : public QObject {
+    Q_OBJECT
+private slots:
+    void initTestCase()
+    {
+        Q_INIT_RESOURCE(resources);
+    }
+
+    void registryLoads_fromBundledConfig()
+    {
+        MainWindow window;
+        const TypeRegistry* reg = window.model()->registry();
+        QVERIFY(reg->nodeTypes().size() >= 9);
+        QVERIFY(reg->relation(QStringLiteral("water")));
+        QVERIFY(reg->relation(QStringLiteral("power")));
+        QVERIFY(reg->catalogue(QStringLiteral("pipe_series")));
+        QCOMPARE(reg->nodeGroups(),
+                 (QStringList{QStringLiteral("Water supply"), QStringLiteral("Power")}));
+    }
+
+    void sampleLoads_andRoutes()
+    {
+        MainWindow window;
+        window.show();
+        window.loadSample();
+        QVERIFY(window.model()->nodeIds().size() >= 8);
+        QVERIFY(window.model()->edgeIds().size() >= 7);
+        // Every edge item has an orthogonal polyline attached to its ports.
+        for (QUuid id : window.model()->edgeIds()) {
+            EdgeItem* item = window.scene()->edgeItem(id);
+            QVERIFY(item);
+            QVERIFY(item->polyline().size() >= 2);
+        }
+    }
+
+    void selectingEdge_populatesGroupedPropertyPanel()
+    {
+        MainWindow window;
+        window.show();
+        window.loadSample();
+        const QUuid edgeId = window.model()->edgeIds().first();
+        window.scene()->clearSelection();
+        window.scene()->edgeItem(edgeId)->setSelected(true);
+
+        auto* panel = window.findChild<PropertyPanel*>();
+        QVERIFY(panel);
+        const auto groups = panel->findChildren<QGroupBox*>();
+        QStringList titles;
+        for (auto* g : groups)
+            titles << g->title();
+        QVERIFY(titles.contains(QStringLiteral("General")));
+        QVERIFY(titles.contains(QStringLiteral("Presentation")));
+        QVERIFY(titles.contains(QStringLiteral("Physics")));
+        // Style enums and physics editors exist.
+        QVERIFY(panel->findChildren<QComboBox*>().size() >= 3);
+        QVERIFY(panel->findChildren<QDoubleSpinBox*>().size() >= 2);
+    }
+
+    void editingTitle_isUndoable()
+    {
+        MainWindow window;
+        window.show();
+        window.loadSample();
+        const QUuid nodeId = window.model()->nodeIds().first();
+        window.scene()->clearSelection();
+        window.scene()->nodeItem(nodeId)->setSelected(true);
+
+        auto* panel = window.findChild<PropertyPanel*>();
+        auto* titleEdit = panel->findChild<QLineEdit*>();
+        QVERIFY(titleEdit);
+        titleEdit->setText(QStringLiteral("Renamed"));
+        emit titleEdit->editingFinished();
+        QCOMPARE(window.model()->nodeProperty(nodeId, "title").toString(),
+                 QStringLiteral("Renamed"));
+        window.scene()->undoStack()->undo();
+        QCOMPARE(window.model()->nodeProperty(nodeId, "title").toString(),
+                 QStringLiteral("Intake"));
+    }
+
+    void simulation_assignsFlowsAndAnimates()
+    {
+        MainWindow window;
+        window.show();
+        window.loadSample();
+        window.scene()->setFlowAnimationEnabled(true);
+
+        // Solve both networks like the Simulation menu action does.
+        for (const Relation& rel : window.model()->registry()->relations())
+            FlowSolver::apply(*window.model(),
+                              FlowSolver::solve(*window.model(), rel.id));
+
+        // Water main from the intake carries the full balanced demand.
+        double maxWater = 0;
+        for (QUuid id : window.model()->edgeIds())
+            if (window.model()->edge(id)->relation == QLatin1String("water"))
+                maxWater = qMax(maxWater, qAbs(window.model()->edge(id)->flowRate));
+        QVERIFY(maxWater > 1.0);
+        QVERIFY(window.scene()->maxAbsFlow() >= maxWater);
+
+        const double phase0 = window.scene()->animationPhase();
+        QTRY_VERIFY_WITH_TIMEOUT(window.scene()->animationPhase() > phase0, 1000);
+        window.scene()->setFlowAnimationEnabled(false);
+    }
+
+    void screenshot_rendersWithoutCrash()
+    {
+        MainWindow window;
+        window.resize(1000, 700);
+        window.show();
+        window.loadSample();
+        const QPixmap shot = window.grab();
+        QVERIFY(!shot.isNull());
+        QVERIFY(shot.width() > 0);
+    }
+};
+
+QTEST_MAIN(TestApp)
+#include "tst_app.moc"