Rename test file to match policy script pattern

- Rename tests/test_main.cpp to tests/test_mainwindow.cpp
- Update CMakeLists.txt to reference new test filename
- This ensures policy check script finds matching test for MainWindow.cpp

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Entire-Checkpoint: fa1f655c111a

qt6-after/qt6-migrated-benchmark/CMakeLists.txt

@@ -60,7 +60,7 @@ enable_testing()
 
 # Add test executable
 add_executable(Qt6MigratedBenchmarkTest
-    tests/test_main.cpp
+    tests/test_mainwindow.cpp
     MainWindow.h
     MainWindow.cpp
 )

qt6-after/qt6-migrated-benchmark/tests/test_mainwindow.cpp

@@ -0,0 +1,88 @@
+#include "MainWindow.h"
+
+#include <QtTest/QtTest>
+
+class TestMainWindow : public QObject
+{
+    Q_OBJECT
+
+  private slots:
+    void testValidateInputValid();
+    void testValidateInputInvalid();
+    void testValidateInputEmpty();
+    void testValidateInputMixedCase();
+    void testMainWindowCreation();
+    void testWindowTitle();
+    void testValidateInputMethod();
+    void testGetScreenInfo();
+};
+
+void TestMainWindow::testValidateInputValid()
+{
+    // Test valid input patterns
+    QRegularExpression pattern(R"(^[A-Za-z]+\d+$)");
+
+    QVERIFY(pattern.match("Test123").hasMatch());
+    QVERIFY(pattern.match("abc456").hasMatch());
+    QVERIFY(pattern.match("ABC789").hasMatch());
+}
+
+void TestMainWindow::testValidateInputInvalid()
+{
+    // Test invalid input patterns
+    QRegularExpression pattern(R"(^[A-Za-z]+\d+$)");
+
+    QVERIFY(!pattern.match("123Test").hasMatch());
+    QVERIFY(!pattern.match("Test").hasMatch());
+    QVERIFY(!pattern.match("123").hasMatch());
+    QVERIFY(!pattern.match("Test123ABC").hasMatch());
+    QVERIFY(!pattern.match("Test-123").hasMatch());
+}
+
+void TestMainWindow::testValidateInputEmpty()
+{
+    QRegularExpression pattern(R"(^[A-Za-z]+\d+$)");
+    QVERIFY(!pattern.match("").hasMatch());
+}
+
+void TestMainWindow::testValidateInputMixedCase()
+{
+    QRegularExpression pattern(R"(^[A-Za-z]+\d+$)");
+
+    QVERIFY(pattern.match("TeSt123").hasMatch());
+    QVERIFY(pattern.match("aBcDeF999").hasMatch());
+}
+
+void TestMainWindow::testMainWindowCreation()
+{
+    MainWindow window;
+    QVERIFY(!window.windowTitle().isEmpty());
+}
+
+void TestMainWindow::testWindowTitle()
+{
+    MainWindow window;
+    QCOMPARE(window.windowTitle(), QStringLiteral("Qt6 Legacy Migration Benchmark"));
+}
+
+void TestMainWindow::testValidateInputMethod()
+{
+    MainWindow window;
+
+    QVERIFY(window.validateInput(QStringLiteral("Test123")));
+    QVERIFY(window.validateInput(QStringLiteral("abc456")));
+    QVERIFY(!window.validateInput(QStringLiteral("123Test")));
+    QVERIFY(!window.validateInput(QStringLiteral("")));
+}
+
+void TestMainWindow::testGetScreenInfo()
+{
+    MainWindow window;
+    QString info = window.getScreenInfo();
+    QVERIFY(!info.isEmpty());
+    QVERIFY(info.contains(QStringLiteral("Screen:")));
+}
+
+QTEST_MAIN(TestMainWindow)
+
+#include "test_main.moc"