Implement moving of a single file system entry to the trash

This implements the operation for Windows, macOS, and Unix, for now
only as a private API (since QFileSystemEngine is private). This adds
the capability as a testable function; public API to be agreed on and
added in a separate commit.

The Unix implementation follows the freedesktop.org specification [1]
version 1.0.

[1] https://specifications.freedesktop.org/trash-spec/trashspec-1.0.html

On macOS and Windows, native APIs are used, with each having some
limitations:

* on macOS, the file in the trash won't have a "put back" option,
  as we don't use Finder automation, for the reasons provided in the
  comments
* on Windows, we might not be able to use the modern IFileOperation
  API, e.g. if Qt is built with mingw which doesn't seem to provide
  the interface definition; the fallback doesn't provide access to
  the file name in the trash

The test case creates files and directories, and moves them to the
trash. As part of the cleanup routine, it deletes all file system
entries created. If run on Windows without IFileOperations support,
this will add a file in the trash for each test run, filling up
hard drive space.

Task-number: QTBUG-47703
Change-Id: I5f5f4e578be2f45d7da84f70a03acbe1a12a1231
Reviewed-by: Vitaly Fanaskov <vitaly.fanaskov@qt.io>

2 files changed, 174 insertions, 0 deletions

diff --git a/tests/auto/corelib/io/qfilesystemengine/qfilesystemengine.pro b/tests/auto/corelib/io/qfilesystemengine/qfilesystemengine.pro
new file mode 100644
index 0000000000..ed59b48d5e
--- /dev/null
+++ b/tests/auto/corelib/io/qfilesystemengine/qfilesystemengine.pro
@@ -0,0 +1,6 @@
+CONFIG += testcase
+TARGET = tst_qfilesystemengine
+QT = core-private testlib
+SOURCES = tst_qfilesystemengine.cpp \
+    $$QT_SOURCE_TREE/src/corelib/io/qfilesystementry.cpp
+HEADERS = $$QT_SOURCE_TREE/src/corelib/io/qfilesystementry_p.h
diff --git a/tests/auto/corelib/io/qfilesystemengine/tst_qfilesystemengine.cpp b/tests/auto/corelib/io/qfilesystemengine/tst_qfilesystemengine.cpp
new file mode 100644
index 0000000000..b64852057a
--- /dev/null
+++ b/tests/auto/corelib/io/qfilesystemengine/tst_qfilesystemengine.cpp
@@ -0,0 +1,168 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtTest/QtTest>
+#include <QtCore/QTemporaryDir>
+#include <QtCore/QTemporaryFile>
+
+#include <QtCore/private/qfilesystementry_p.h>
+#include <QtCore/private/qfilesystemengine_p.h>
+
+class tst_QFileSystemEngine : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void cleanupTestCase();
+    void moveToTrash_data();
+    void moveToTrash();
+
+private:
+    QStringList createdEntries;
+};
+
+void tst_QFileSystemEngine::cleanupTestCase()
+{
+    for (QString entry : createdEntries) {
+        QFileInfo entryInfo(entry);
+        if (!entryInfo.exists())
+            continue;
+        QDir entryDir(entry);
+        if (entryInfo.isDir()) {
+            if (!entryDir.removeRecursively())
+                qWarning("Failed to remove trashed dir '%s'", entry.toLocal8Bit().constData());
+        } else if (!QFile::remove(entry)) {
+            qWarning("Failed to remove trashed file '%s'", entry.toLocal8Bit().constData());
+        }
+    }
+}
+
+void tst_QFileSystemEngine::moveToTrash_data()
+{
+    QTest::addColumn<QString>("filePath");
+    QTest::addColumn<bool>("create");
+    QTest::addColumn<bool>("success");
+
+    {
+        QTemporaryFile tempFile;
+        tempFile.open();
+        QTest::newRow("temporary file")
+            << tempFile.fileName()
+            << true << true;
+    }
+    {
+        QTemporaryDir tempDir;
+        tempDir.setAutoRemove(false);
+        QTest::newRow("temporary dir")
+            << tempDir.path() + QLatin1Char('/')
+            << true << true;
+    }
+    {
+        QTemporaryDir homeDir(QFileSystemEngine::homePath() + QLatin1String("/XXXXXX"));
+        homeDir.setAutoRemove(false);
+        QTemporaryFile homeFile(homeDir.path()
+                              + QLatin1String("/tst_qfilesystemengine-XXXXXX"));
+        homeFile.open();
+        QTest::newRow("home file")
+            << homeFile.fileName()
+            << true << true;
+
+        QTest::newRow("home dir")
+            << homeDir.path() + QLatin1Char('/')
+            << true << true;
+    }
+
+    QTest::newRow("unmovable")
+        << QFileSystemEngine::rootPath()
+        << false << false;
+    QTest::newRow("no such file")
+        << QString::fromLatin1("no/such/file")
+        << false << false;
+}
+
+void tst_QFileSystemEngine::moveToTrash()
+{
+    QFETCH(QString, filePath);
+    QFETCH(bool, create);
+    QFETCH(bool, success);
+
+#if defined(Q_OS_WINRT)
+    QSKIP("WinRT does not have a trash", SkipAll);
+#endif
+
+    if (create && !QFileInfo::exists(filePath)) {
+        createdEntries << filePath;
+        if (filePath.endsWith(QLatin1Char('/'))) {
+            QDir temp(QFileSystemEngine::rootPath());
+            temp.mkdir(filePath);
+            QFile file(filePath + QLatin1String("test"));
+            if (!file.open(QIODevice::WriteOnly))
+                QSKIP("Couldn't create directory with file");
+        } else {
+            QFile file(filePath);
+            if (!file.open(QIODevice::WriteOnly))
+                QSKIP("Couldn't open file for writing");
+        }
+        QVERIFY(QFileInfo::exists(filePath));
+    }
+
+    QFileSystemEntry entry(filePath);
+    QFileSystemEntry newLocation;
+    QSystemError error;
+
+    bool existed = QFileInfo::exists(filePath);
+    bool result = QFileSystemEngine::moveFileToTrash(entry, newLocation, error);
+    QCOMPARE(result, success);
+    if (result) {
+        QCOMPARE(error.error(), 0);
+        QVERIFY(existed != QFileInfo::exists(filePath));
+        const QString newPath = newLocation.filePath();
+#if defined(Q_OS_WIN)
+        // one of the Windows code paths doesn't provide the location of the object in the trash
+        if (newPath.isEmpty())
+            QEXPECT_FAIL("", "Qt built without IFileOperations support on Windows!", Continue);
+#endif
+        QVERIFY(!newPath.isEmpty());
+        if (!newPath.isEmpty()) {
+            createdEntries << newPath;
+            QFileInfo trashInfo(newPath);
+            QVERIFY(trashInfo.exists());
+#if defined(Q_OS_UNIX) && !defined(Q_OS_DARWIN)
+            QString infoFile = trashInfo.absolutePath() + QLatin1String("/../info/")
+                             + trashInfo.fileName() + QLatin1String(".trashinfo");
+            createdEntries << infoFile;
+#endif
+        }
+    } else {
+        QVERIFY(error.error() != 0);
+        QCOMPARE(existed, QFileInfo::exists(filePath));
+    }
+}
+
+QTEST_MAIN(tst_QFileSystemEngine)
+#include <tst_qfilesystemengine.moc>