From c1d5fdd04a8e57836fb3040c0d0fda843fc095a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Cie=C5=9Blak?= <michalcieslak@status.im>
Date: Wed, 16 Nov 2022 14:37:23 +0100
Subject: [PATCH] feat(Storybook): sections decorator model impl and basic
 tests

Proxy model extending source model by adding foldable sections
based on "section" role from the source model.
---
 storybook/CMakeLists.txt                      |   8 +-
 storybook/sectionsdecoratormodel.cpp          | 162 ++++++
 storybook/sectionsdecoratormodel.h            |  46 ++
 .../tests/tst_SectionsDecoratorModel.cpp      | 502 ++++++++++++++++++
 4 files changed, 717 insertions(+), 1 deletion(-)
 create mode 100644 storybook/sectionsdecoratormodel.cpp
 create mode 100644 storybook/sectionsdecoratormodel.h
 create mode 100644 storybook/tests/tst_SectionsDecoratorModel.cpp

diff --git a/storybook/CMakeLists.txt b/storybook/CMakeLists.txt
index c54e06481f..7265270872 100644
--- a/storybook/CMakeLists.txt
+++ b/storybook/CMakeLists.txt
@@ -17,7 +17,7 @@ endif()
 
 find_package(
   Qt5
-  COMPONENTS Core Quick QuickControls2 WebEngine
+  COMPONENTS Core Quick QuickControls2 WebEngine Test
   REQUIRED)
 
 file(GLOB_RECURSE QML_FILES "stubs/*.qml" "mocks/*.qml" "pages/*.qml" "src/*.qml" "src/qmldir" "../ui/StatusQ/*.qml" "../ui/app/*.qml")
@@ -28,6 +28,7 @@ add_executable(
   main.cpp
   cachecleaner.cpp cachecleaner.h
   directorieswatcher.cpp directorieswatcher.h
+  sectionsdecoratormodel.cpp sectionsdecoratormodel.h
   ${QML_FILES} main.qml
   ${JS_FILES}
 )
@@ -38,6 +39,11 @@ target_link_libraries(
   ${PROJECT_NAME} PRIVATE Qt5::Core Qt5::Quick Qt5::QuickControls2 Qt5::WebEngine
                           SortFilterProxyModel)
 
+enable_testing()
+add_executable(SectionsDecoratorModelTest tests/tst_SectionsDecoratorModel.cpp sectionsdecoratormodel.cpp)
+add_test(NAME SectionsDecoratorModelTest COMMAND SectionsDecoratorModelTest)
+target_link_libraries(SectionsDecoratorModelTest PRIVATE Qt5::Test)
+
 list(APPEND QML_DIRS "${CMAKE_SOURCE_DIR}/../ui/StatusQ/src")
 list(APPEND QML_DIRS "${CMAKE_SOURCE_DIR}/../ui/app")
 list(APPEND QML_DIRS "${CMAKE_SOURCE_DIR}/../ui/imports")
diff --git a/storybook/sectionsdecoratormodel.cpp b/storybook/sectionsdecoratormodel.cpp
new file mode 100644
index 0000000000..c41f4ba04f
--- /dev/null
+++ b/storybook/sectionsdecoratormodel.cpp
@@ -0,0 +1,162 @@
+#include "sectionsdecoratormodel.h"
+
+#include <QScopeGuard>
+
+SectionsDecoratorModel::SectionsDecoratorModel(QObject *parent)
+    : QAbstractListModel{parent}
+{
+}
+
+void SectionsDecoratorModel::setSourceModel(QAbstractItemModel *sourceModel)
+{
+    if (m_sourceModel != nullptr) {
+        qWarning("Changing source model is not supported!");
+        return;
+    }
+
+    m_sourceModel = sourceModel;
+
+    initialize();
+
+    connect(sourceModel, &QAbstractItemModel::modelReset, this, &SectionsDecoratorModel::initialize);
+    connect(sourceModel, &QAbstractItemModel::rowsInserted, this, &SectionsDecoratorModel::initialize);
+    connect(sourceModel, &QAbstractItemModel::rowsRemoved, this, &SectionsDecoratorModel::initialize);
+    connect(sourceModel, &QAbstractItemModel::rowsMoved, this, &SectionsDecoratorModel::initialize);
+
+    emit sourceModelChanged();
+}
+
+QAbstractItemModel* SectionsDecoratorModel::sourceModel() const
+{
+    return m_sourceModel;
+}
+
+int SectionsDecoratorModel::rowCount(const QModelIndex &parent) const
+{
+    return m_rowsMetadata.size();
+}
+
+QVariant SectionsDecoratorModel::data(const QModelIndex &index, int role) const
+{
+    if (!checkIndex(index, CheckIndexOption::IndexIsValid))
+        return {};
+
+    const int row = index.row();
+    const RowMetadata &rowMetadata = m_rowsMetadata[row];
+
+    if (role == IsFoldedRole) {
+        return rowMetadata.folded;
+    } else if (role == SubitemsCountRole) {
+        return rowMetadata.count;
+    } else if (role == IsSectionRole) {
+        return rowMetadata.isSection;
+    } else if (role == m_sectionRole && rowMetadata.isSection) {
+        return rowMetadata.sectionName;
+    }
+
+    if (!rowMetadata.isSection) {
+        return sourceModel()->data(
+                    sourceModel()->index(row - rowMetadata.offset, 0), role);
+    } else {
+        return QVariant();
+    }
+}
+
+QHash<int, QByteArray> SectionsDecoratorModel::roleNames() const
+{
+    auto roles = m_sourceModel ? m_sourceModel->roleNames() : QHash<int, QByteArray>{};
+    roles.insert(IsSectionRole, QByteArrayLiteral("isSection"));
+    roles.insert(IsFoldedRole, QByteArrayLiteral("isFolded"));
+    roles.insert(SubitemsCountRole, QByteArrayLiteral("subitemsCount"));
+
+    return roles;
+}
+
+void SectionsDecoratorModel::flipFolding(int index)
+{
+    auto &row = m_rowsMetadata[index];
+    row.folded = !row.folded;
+
+    const auto idx = this->index(index, 0, {});
+
+    if (row.folded) {
+        beginRemoveRows(QModelIndex(), index + 1, index + row.count);
+        m_rowsMetadata.erase(m_rowsMetadata.begin() + index + 1,
+                             m_rowsMetadata.begin() + index + 1 + row.count);
+        calculateOffsets();
+        endRemoveRows();
+    } else {
+        beginInsertRows(QModelIndex(), index + 1, index + row.count);
+        m_rowsMetadata.insert(m_rowsMetadata.begin() + index + 1, row.count,
+                              RowMetadata{false});
+        calculateOffsets();
+        endInsertRows();
+    }
+
+    emit dataChanged(idx, idx, { IsFoldedRole });
+}
+
+void SectionsDecoratorModel::calculateOffsets()
+{
+    std::for_each(m_rowsMetadata.begin(), m_rowsMetadata.end(),
+                  [offset = 0](RowMetadata &row) mutable {
+        if (row.isSection) {
+            ++offset;
+
+            if (row.folded)
+                offset -= row.count;
+        } else {
+            row.offset = offset;
+        }
+    });
+}
+
+std::optional<int> SectionsDecoratorModel::findSectionRole() const
+{
+    const auto roleNames = m_sourceModel->roleNames();
+    auto i = roleNames.constBegin();
+
+    while (i != roleNames.constEnd()) {
+        if (i.value() == QStringLiteral("section"))
+            return i.key();
+        ++i;
+    }
+
+    return std::nullopt;
+}
+
+void SectionsDecoratorModel::initialize()
+{
+    beginResetModel();
+    auto endResetModelGuard = qScopeGuard([this] { endResetModel(); });
+
+    m_rowsMetadata.clear();
+
+    const auto sectionRoleOpt = findSectionRole();
+
+    if (!sectionRoleOpt) {
+        qWarning("Section role not found!");
+        return;
+    }
+
+    m_sectionRole = *sectionRoleOpt;
+    QString prevSection;
+    int prevSectionIndex = 0;
+
+    for (int i = 0; i < m_sourceModel->rowCount(); i++) {
+        const QVariant sectionVariant = m_sourceModel->data(
+                    m_sourceModel->index(i, 0), m_sectionRole);
+        const QString section = sectionVariant.toString();
+
+        if (prevSection != section) {
+            m_rowsMetadata.push_back({true, section});
+            prevSection = section;
+            prevSectionIndex = m_rowsMetadata.size() - 1;
+        }
+
+        m_rowsMetadata.push_back({false});
+        m_rowsMetadata[prevSectionIndex].count++;
+    }
+
+    calculateOffsets();
+}
diff --git a/storybook/sectionsdecoratormodel.h b/storybook/sectionsdecoratormodel.h
new file mode 100644
index 0000000000..98e4f69988
--- /dev/null
+++ b/storybook/sectionsdecoratormodel.h
@@ -0,0 +1,46 @@
+#pragma once
+
+#include <QAbstractListModel>
+#include <optional>
+
+class SectionsDecoratorModel : public QAbstractListModel
+{
+    Q_OBJECT
+    Q_PROPERTY(QAbstractItemModel* sourceModel READ sourceModel
+               WRITE setSourceModel NOTIFY sourceModelChanged)
+public:
+    static constexpr int IsSectionRole = Qt::UserRole + 100;
+    static constexpr int IsFoldedRole = Qt::UserRole + 101;
+    static constexpr int SubitemsCountRole = Qt::UserRole + 102;
+
+    explicit SectionsDecoratorModel(QObject *parent = nullptr);
+
+    void setSourceModel(QAbstractItemModel *sourceModel);
+    QAbstractItemModel *sourceModel() const;
+
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    QVariant data(const QModelIndex &index, int role) const override;
+    QHash<int, QByteArray> roleNames() const override;
+
+    Q_INVOKABLE void flipFolding(int index);
+
+signals:
+    void sourceModelChanged();
+
+private:
+    struct RowMetadata {
+        bool isSection = false;
+        QString sectionName;
+        bool folded = false;
+        int offset = 0;
+        int count = 0;
+    };
+
+    std::optional<int> findSectionRole() const;
+    void initialize();
+    void calculateOffsets();
+
+    QAbstractItemModel* m_sourceModel = nullptr;
+    std::vector<RowMetadata> m_rowsMetadata;
+    int m_sectionRole = 0;
+};
diff --git a/storybook/tests/tst_SectionsDecoratorModel.cpp b/storybook/tests/tst_SectionsDecoratorModel.cpp
new file mode 100644
index 0000000000..aa27fe31ee
--- /dev/null
+++ b/storybook/tests/tst_SectionsDecoratorModel.cpp
@@ -0,0 +1,502 @@
+#include <QSignalSpy>
+#include <QTest>
+
+#include <QAbstractListModel>
+#include <QSortFilterProxyModel>
+
+#include <sectionsdecoratormodel.h>
+
+namespace {
+
+class TestSourceModel : public QAbstractListModel {
+
+public:
+    explicit TestSourceModel(QStringList sections)
+        : m_sections(std::move(sections))
+    {
+    }
+
+    static constexpr int TitleRole = Qt::UserRole + 1;
+    static constexpr int SectionRole = Qt::UserRole + 2;
+
+    int rowCount(const QModelIndex &parent) const override {
+        return m_sections.size();
+    }
+
+    QVariant data(const QModelIndex &index, int role) const override {
+        if (!index.isValid())
+            return {};
+
+        if (role == TitleRole) {
+            return QString("title %1").arg(index.row());
+        }
+
+        return m_sections.at(index.row());
+    }
+
+    QHash<int, QByteArray> roleNames() const override {
+        QHash<int, QByteArray> roles;
+        roles.insert(TitleRole, "title");
+        roles.insert(SectionRole, "section");
+        return roles;
+    }
+
+    QStringList m_sections;
+};
+
+} // unnamed namespace
+
+class TestSectionsDecoratorModel: public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void emptyModelTest() {
+        SectionsDecoratorModel model;
+
+        QCOMPARE(model.rowCount(), 0);
+        QCOMPARE(model.roleNames().count(), 3);
+        QVERIFY(model.roleNames().contains(SectionsDecoratorModel::IsSectionRole));
+        QVERIFY(model.roleNames().contains(SectionsDecoratorModel::IsFoldedRole));
+        QVERIFY(model.roleNames().contains(SectionsDecoratorModel::SubitemsCountRole));
+    }
+
+    void emptySourceTest() {
+        TestSourceModel src(QStringList{});
+        SectionsDecoratorModel model;
+        model.setSourceModel(&src);
+
+        QCOMPARE(model.rowCount(), 0);
+        QCOMPARE(model.roleNames().count(), 5);
+        QVERIFY(model.roleNames().contains(SectionsDecoratorModel::IsSectionRole));
+        QVERIFY(model.roleNames().contains(SectionsDecoratorModel::IsFoldedRole));
+        QVERIFY(model.roleNames().contains(SectionsDecoratorModel::SubitemsCountRole));
+        QVERIFY(model.roleNames().contains(TestSourceModel::TitleRole));
+        QVERIFY(model.roleNames().contains(TestSourceModel::SectionRole));
+    }
+
+    void initialUnfoldedStateTest() {
+        TestSourceModel src(QStringList{"Section 1", "Section 1", "Section 1", "Section 2", "Section 2", "Section 3"});
+        SectionsDecoratorModel model;
+        model.setSourceModel(&src);
+
+        QCOMPARE(model.rowCount(), 9);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 0"));
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 2"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole).toString(), QString("title 3"));
+        QCOMPARE(model.data(model.index(6, 0), TestSourceModel::TitleRole).toString(), QString("title 4"));
+        QCOMPARE(model.data(model.index(7, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(8, 0), TestSourceModel::TitleRole).toString(), QString("title 5"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+    }
+
+    void foldingFromTopToBottomTest() {
+        TestSourceModel src(QStringList{"Section 1", "Section 1", "Section 1", "Section 2", "Section 2", "Section 3"});
+        SectionsDecoratorModel model;
+        model.setSourceModel(&src);
+
+        model.flipFolding(0);
+
+        QCOMPARE(model.rowCount(), 6);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 3"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 4"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole).toString(), QString("title 5"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+
+        model.flipFolding(1);
+        QCOMPARE(model.rowCount(), 4);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 5"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+
+        model.flipFolding(2);
+
+        QCOMPARE(model.rowCount(), 3);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole), QVariant{});
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+    }
+
+    void foldingFromBottomToTopTest() {
+        TestSourceModel src(QStringList{"Section 1", "Section 1", "Section 1", "Section 2", "Section 2", "Section 3"});
+        SectionsDecoratorModel model;
+        model.setSourceModel(&src);
+        model.flipFolding(7);
+
+        QCOMPARE(model.rowCount(), 8);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 0"));
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 2"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole).toString(), QString("title 3"));
+        QCOMPARE(model.data(model.index(6, 0), TestSourceModel::TitleRole).toString(), QString("title 4"));
+        QCOMPARE(model.data(model.index(7, 0), TestSourceModel::TitleRole), QVariant{});
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+
+        model.flipFolding(4);
+
+        QCOMPARE(model.rowCount(), 6);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 0"));
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 2"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole), QVariant{});
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+
+        model.flipFolding(0);
+
+        QCOMPARE(model.rowCount(), 3);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole), QVariant{});
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), true);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+    }
+
+    void unfoldingTest() {
+        TestSourceModel src(QStringList{"Section 1", "Section 1", "Section 1", "Section 2", "Section 2", "Section 3"});
+        SectionsDecoratorModel model;
+        model.setSourceModel(&src);
+
+        model.flipFolding(0);
+        model.flipFolding(1);
+        model.flipFolding(2);
+
+        model.flipFolding(2);
+        model.flipFolding(1);
+        model.flipFolding(0);
+
+        QCOMPARE(model.rowCount(), 9);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 0"));
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 2"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole).toString(), QString("title 3"));
+        QCOMPARE(model.data(model.index(6, 0), TestSourceModel::TitleRole).toString(), QString("title 4"));
+        QCOMPARE(model.data(model.index(7, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(8, 0), TestSourceModel::TitleRole).toString(), QString("title 5"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+
+        model.flipFolding(0);
+        model.flipFolding(1);
+        model.flipFolding(2);
+
+        model.flipFolding(0);
+        model.flipFolding(4);
+        model.flipFolding(7);
+
+        QCOMPARE(model.rowCount(), 9);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 0"));
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 2"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole).toString(), QString("title 3"));
+        QCOMPARE(model.data(model.index(6, 0), TestSourceModel::TitleRole).toString(), QString("title 4"));
+        QCOMPARE(model.data(model.index(7, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(8, 0), TestSourceModel::TitleRole).toString(), QString("title 5"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+    }
+
+    void basicFilteringTest() {
+        TestSourceModel src(QStringList{"Section 1", "Section 1", "Section 1", "Section 2", "Section 2", "Section 3"});
+
+        QSortFilterProxyModel proxy;
+        proxy.setSourceModel(&src);
+
+        SectionsDecoratorModel model;
+        model.setSourceModel(&proxy);
+
+        QCOMPARE(model.rowCount(), 9);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 0"));
+        QCOMPARE(model.data(model.index(2, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+        QCOMPARE(model.data(model.index(3, 0), TestSourceModel::TitleRole).toString(), QString("title 2"));
+        QCOMPARE(model.data(model.index(4, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(5, 0), TestSourceModel::TitleRole).toString(), QString("title 3"));
+        QCOMPARE(model.data(model.index(6, 0), TestSourceModel::TitleRole).toString(), QString("title 4"));
+        QCOMPARE(model.data(model.index(7, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(8, 0), TestSourceModel::TitleRole).toString(), QString("title 5"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(6, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 3);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(2, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(3, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(4, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 2);
+        QCOMPARE(model.data(model.index(5, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+        QCOMPARE(model.data(model.index(7, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(8, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+    }
+
+    void filteringTest() {
+        TestSourceModel src(QStringList{"Section 1", "Section 1", "Section 1", "Section 2", "Section 2", "Section 3"});
+
+        QSortFilterProxyModel proxy;
+        proxy.setSourceModel(&src);
+
+        SectionsDecoratorModel model;
+        model.setSourceModel(&proxy);
+
+        QSignalSpy spy(&model, SIGNAL(modelReset()));
+
+        proxy.setFilterRole(TestSourceModel::TitleRole);
+        proxy.setFilterWildcard("*1");
+
+        QVERIFY(spy.count() > 1);
+
+        QCOMPARE(model.rowCount(), 2);
+        QCOMPARE(model.roleNames().count(), 5);
+
+        QCOMPARE(model.data(model.index(0, 0), TestSourceModel::TitleRole), QVariant{});
+        QCOMPARE(model.data(model.index(1, 0), TestSourceModel::TitleRole).toString(), QString("title 1"));
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsSectionRole).toBool(), true);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsSectionRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::IsFoldedRole).toBool(), false);
+
+        QCOMPARE(model.data(model.index(0, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 1);
+        QCOMPARE(model.data(model.index(1, 0), SectionsDecoratorModel::SubitemsCountRole).toInt(), 0);
+    }
+};
+
+// TODO: signals emission testing using QSignalSpy
+
+QTEST_MAIN(TestSectionsDecoratorModel)
+#include "tst_SectionsDecoratorModel.moc"