Stabilize QFileSystemModel::dirsBeforeFiles test

Make the test operate in its own temporary directory, so that entries
left behind by other test functions don't impact this test.

Also, call QFileSystemModel::sort explicitly; it would otherwise only
be done once through a single-shot timer, and the test processes events
until the model is populated, which might not process that delayed
sorting. Since dirsBeforeFiles tests the sorting algorithm and not
the sorting logic, best to do this explicitly.

In case of sort failure, print diagnostics.

Change-Id: I44c2b82ef1330cc8787aed2b5cbf109ef3a67876
Done-with: Friedemann Kleint <Friedemann.Kleint@qt.io>
Fixes: QTBUG-75452
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

1 files changed, 18 insertions, 10 deletions

diff --git a/tests/auto/widgets/dialogs/qfilesystemmodel/tst_qfilesystemmodel.cpp b/tests/auto/widgets/dialogs/qfilesystemmodel/tst_qfilesystemmodel.cpp
index 7398cc103e..2c0b3f2bcb 100644
--- a/tests/auto/widgets/dialogs/qfilesystemmodel/tst_qfilesystemmodel.cpp
+++ b/tests/auto/widgets/dialogs/qfilesystemmodel/tst_qfilesystemmodel.cpp
@@ -1014,30 +1014,38 @@ void tst_QFileSystemModel::drives()
 
 void tst_QFileSystemModel::dirsBeforeFiles()
 {
-    QDir dir(flatDirTestPath);
+    auto diagnosticMsg = [](int row, const QFileInfo &left, const QFileInfo &right) -> QByteArray {
+        QString message;
+        QDebug(&message).noquote() << "Unexpected sort order at #" << row << ':' << left << right;
+        return message.toLocal8Bit();
+    };
+    QTemporaryDir testDir(flatDirTestPath);
+    QVERIFY2(testDir.isValid(), qPrintable(testDir.errorString()));
+    QDir dir(testDir.path());
 
     const int itemCount = 3;
     for (int i = 0; i < itemCount; ++i) {
         QLatin1Char c('a' + char(i));
         QVERIFY(dir.mkdir(c + QLatin1String("-dir")));
-        QFile file(flatDirTestPath + QLatin1Char('/') + c + QLatin1String("-file"));
+        QFile file(dir.filePath(c + QLatin1String("-file")));
         QVERIFY(file.open(QIODevice::ReadWrite));
         file.close();
     }
 
     QScopedPointer<QFileSystemModel> model(new QFileSystemModel);
-    QModelIndex root = model->setRootPath(flatDirTestPath);
+    QModelIndex root = model->setRootPath(dir.absolutePath());
     // Wait for model to be notified by the file system watcher
     QTRY_COMPARE(model->rowCount(root), 2 * itemCount);
-
-    // Ensure that no file occurs before any directory:
-    for (int i = 1; i < model->rowCount(root); ++i) {
+    // sort explicitly - dirs before files (except on macOS), and then by name
+    model->sort(0);
+    // Ensure that no file occurs before any directory (see QFileSystemModelSorter):
+    for (int i = 1, count = model->rowCount(root); i < count; ++i) {
+        const QFileInfo previous = model->fileInfo(model->index(i - 1, 0, root));
+        const QFileInfo current = model->fileInfo(model->index(i, 0, root));
 #ifndef Q_OS_MAC
-        QVERIFY(!(model->fileInfo(model->index(i - 1, 0, root)).isFile()
-                  && model->fileInfo(model->index(i, 0, root)).isDir()));
+        QVERIFY2(!(previous.isFile() && current.isDir()), diagnosticMsg(i, previous, current).constData());
 #else
-        QVERIFY(model->fileInfo(model->index(i - 1, 0, root)).fileName() <
-                model->fileInfo(model->index(i, 0, root)).fileName());
+        QVERIFY2(previous.fileName() < current.fileName(), diagnosticMsg(i, previous, current).constData());
 #endif
     }
 }