Merge pull request #1501 from ispyisail/feat/keep-previous-versions

Add keeping the previous versions of a project each time it is saved

tests/qttest/CMakeLists.txt

@@ -1264,6 +1264,17 @@ if(Qt6_VERSION VERSION_LESS 6.5.0)
   endforeach()
 endif()
 
+# The versions of a project kept before it is saved over: the newest
+# kept, same bytes not kept twice, a failed copy said
+# (sources/utils/previousversions.*).
+add_executable(
+  tst_previousversions
+  tst_previousversions.cpp
+  ${QET_DIR}/sources/utils/previousversions.cpp)
+add_test(NAME tst_previousversions COMMAND tst_previousversions)
+target_include_directories(tst_previousversions PRIVATE ${QET_DIR}/sources)
+target_link_libraries(tst_previousversions PRIVATE Qt::Test)
+
 # The zip a .qetz project is stored in: round trip, same bytes twice,
 # unsafe entry names refused (sources/container/qetzip.*, bundled miniz).
 add_executable(

tests/qttest/tst_previousversions.cpp

@@ -0,0 +1,127 @@
+/*
+	Copyright 2006-2026 The QElectroTech Team
+	This file is part of QElectroTech.
+
+	QElectroTech is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 2 of the License, or
+	(at your option) any later version.
+
+	QElectroTech is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
+*/
+#include <QtTest>
+
+#include <QDateTime>
+#include <QFile>
+#include <QTemporaryDir>
+
+#include "utils/previousversions.h"
+
+// The versions of a project kept before it is saved over
+// (sources/utils/previousversions.*)
+class tst_previousversions : public QObject
+{
+	Q_OBJECT
+
+	QTemporaryDir m_dir;
+
+		// @p path holding @p text, saved at @p when
+	static void write(const QString &path, const QByteArray &text, const QDateTime &when)
+	{
+		QFile file(path);
+		QVERIFY(file.open(QIODevice::WriteOnly | QIODevice::Truncate));
+		file.write(text);
+		file.flush();	//else closing writes, and sets the time to now
+		QVERIFY(file.setFileTime(when, QFileDevice::FileModificationTime));
+	}
+
+	static QByteArray read(const QString &path)
+	{
+		QFile file(path);
+		return file.open(QIODevice::ReadOnly) ? file.readAll() : QByteArray();
+	}
+
+private slots:
+	void initTestCase() { QVERIFY(m_dir.isValid()); }
+
+	// Each save keeps the file as it was, newest first, named by the time
+	// that version was saved, in "<name>-backups" beside it; only the
+	// newest are kept
+	void keepsTheNewest()
+	{
+		const QString project = m_dir.filePath(QStringLiteral("plant.qetz"));
+		const QDateTime start(QDate(2026, 10, 16), QTime(8, 0, 0));
+		for (int i = 0 ; i < 7 ; ++i) {
+			write(project, "version " + QByteArray::number(i), start.addSecs(60 * i));
+			QVERIFY(PreviousVersions::keep(project, 3));
+		}
+		const QStringList kept = PreviousVersions::kept(project);
+		QCOMPARE(kept.size(), 3);
+		QCOMPARE(read(kept.at(0)), QByteArray("version 6"));
+		QCOMPARE(read(kept.at(2)), QByteArray("version 4"));
+		QCOMPARE(QFileInfo(kept.at(0)).fileName(), QStringLiteral("plant 2026-10-16 08-06-00.qetz"));
+		QCOMPARE(QFileInfo(kept.at(0)).absolutePath(), m_dir.filePath(QStringLiteral("plant-backups")));
+			// The project itself is untouched
+		QCOMPARE(read(project), QByteArray("version 6"));
+	}
+
+	// Saving the same bytes again keeps no second copy
+	void sameBytesNotKeptTwice()
+	{
+		const QString project = m_dir.filePath(QStringLiteral("same.qet"));
+		const QDateTime when(QDate(2026, 10, 16), QTime(9, 0, 0));
+		write(project, "unchanged", when);
+		QVERIFY(PreviousVersions::keep(project, 5));
+		write(project, "unchanged", when.addSecs(30));
+		QVERIFY(PreviousVersions::keep(project, 5));
+		QCOMPARE(PreviousVersions::kept(project).size(), 1);
+	}
+
+	// Two versions saved the same second both kept
+	void sameSecond()
+	{
+		const QString project = m_dir.filePath(QStringLiteral("fast.qetz"));
+		const QDateTime when(QDate(2026, 10, 16), QTime(10, 0, 0));
+		write(project, "first", when);
+		QVERIFY(PreviousVersions::keep(project, 5));
+		write(project, "second", when);
+		QVERIFY(PreviousVersions::keep(project, 5));
+		QCOMPARE(PreviousVersions::kept(project).size(), 2);
+	}
+
+	// Nothing kept for a new file, or when the count is 0; another
+	// project's versions in the same folder are not counted
+	void nothingToKeep()
+	{
+		const QString project = m_dir.filePath(QStringLiteral("new.qetz"));
+		QVERIFY(PreviousVersions::keep(project, 5));
+		QVERIFY(!QFileInfo::exists(PreviousVersions::folder(project)));
+		write(project, "x", QDateTime(QDate(2026, 10, 16), QTime(11, 0, 0)));
+		QVERIFY(PreviousVersions::keep(project, 0));
+		QVERIFY(!QFileInfo::exists(PreviousVersions::folder(project)));
+		QVERIFY(PreviousVersions::kept(m_dir.filePath(QStringLiteral("other.qetz"))).isEmpty());
+	}
+
+	// A copy that cannot be made says so, and leaves the project as it is
+	void copyFails()
+	{
+		const QString project = m_dir.filePath(QStringLiteral("blocked.qetz"));
+		write(project, "data", QDateTime(QDate(2026, 10, 16), QTime(12, 0, 0)));
+			// A file where the folder should be
+		write(PreviousVersions::folder(project), "", QDateTime::currentDateTime());
+		QString error;
+		QVERIFY(!PreviousVersions::keep(project, 5, &error));
+		QVERIFY(!error.isEmpty());
+		QCOMPARE(read(project), QByteArray("data"));
+	}
+};
+
+QTEST_GUILESS_MAIN(tst_previousversions)
+
+#include "tst_previousversions.moc"