QTestlib: Add formatting for QObject * in QCOMPARE

Output object name and class in QCOMPARE(). This should help
to debug flaky QWidget tests that for example check on focusWidget().

[ChangeLog][QtTestLib] QCOMPARE() now reports QObject * values by class and objectName().

Task-number: QTBUG-64446
Change-Id: Ife04e89bba04fc78d077c8f0f07af17a17c9cf8c
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

2 files changed, 40 insertions, 0 deletions

diff --git a/src/testlib/qtestcase.cpp b/src/testlib/qtestcase.cpp
index daaa1bc390..596f521ffa 100644
--- a/src/testlib/qtestcase.cpp
+++ b/src/testlib/qtestcase.cpp
@@ -2822,6 +2822,24 @@ char *QTest::toString(const void *p)
     return msg;
 }
 
+/*! \internal
+ */
+char *QTest::toString(const volatile QObject *vo)
+{
+    if (vo == nullptr)
+        return qstrdup("<null>");
+
+    auto *o = const_cast<const QObject*>(vo);
+    const QString &name = o->objectName();
+    const char *className = o->metaObject()->className();
+    char *msg = new char[256];
+    if (name.isEmpty())
+        qsnprintf(msg, 256, "%s/%p", className, o);
+    else
+        qsnprintf(msg, 256, "%s/\"%s\"", className, qPrintable(name));
+    return msg;
+}
+
 /*! \fn char *QTest::toString(const QColor &color)
     \internal
  */
diff --git a/src/testlib/qtestcase.h b/src/testlib/qtestcase.h
index 3fe6d2d867..b046232c65 100644
--- a/src/testlib/qtestcase.h
+++ b/src/testlib/qtestcase.h
@@ -297,6 +297,7 @@ namespace QTest
     Q_TESTLIB_EXPORT char *toString(const char *);
     Q_TESTLIB_EXPORT char *toString(const volatile void *);
     Q_TESTLIB_EXPORT char *toString(const void *); // ### FIXME: Qt 7: Remove
+    Q_TESTLIB_EXPORT char *toString(const volatile QObject *);
 
     Q_TESTLIB_EXPORT void qInit(QObject *testObject, int argc = 0, char **argv = nullptr);
     Q_TESTLIB_EXPORT int qRun();
@@ -421,6 +422,27 @@ namespace QTest
                               toString(t1), toString(t2), actual, expected, file, line);
     }
 
+    inline bool compare_ptr_helper(const volatile QObject *t1, const volatile QObject *t2, const char *actual,
+                                   const char *expected, const char *file, int line)
+    {
+        return compare_helper(t1 == t2, "Compared QObject pointers are not the same",
+                              toString(t1), toString(t2), actual, expected, file, line);
+    }
+
+    inline bool compare_ptr_helper(const volatile QObject *t1, std::nullptr_t, const char *actual,
+                                   const char *expected, const char *file, int line)
+    {
+        return compare_helper(t1 == nullptr, "Compared QObject pointers are not the same",
+                              toString(t1), toString(nullptr), actual, expected, file, line);
+    }
+
+    inline bool compare_ptr_helper(std::nullptr_t, const volatile QObject *t2, const char *actual,
+                                   const char *expected, const char *file, int line)
+    {
+        return compare_helper(nullptr == t2, "Compared QObject pointers are not the same",
+                              toString(nullptr), toString(t2), actual, expected, file, line);
+    }
+
     inline bool compare_ptr_helper(const volatile void *t1, std::nullptr_t, const char *actual,
                                    const char *expected, const char *file, int line)
     {