Implement QJsonObject data stream operator

Change-Id: I8528f18ad72828cd97a5ac00e1925958acf73f9f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/serialization/qjsonobject.cpp

@@ -1320,4 +1320,21 @@ QDebug operator<<(QDebug dbg, const QJsonObject &o)
 }
 #endif
 
+#ifndef QT_NO_DATASTREAM
+QDataStream &operator<<(QDataStream &stream, const QJsonObject &object)
+{
+    QJsonDocument doc{object};
+    stream << doc.toJson(QJsonDocument::Compact);
+    return stream;
+}
+
+QDataStream &operator>>(QDataStream &stream, QJsonObject &object)
+{
+    QJsonDocument doc;
+    stream >> doc;
+    object = doc.object();
+    return stream;
+}
+#endif
+
 QT_END_NAMESPACE

src/corelib/serialization/qjsonobject.h

@@ -268,6 +268,11 @@ Q_CORE_EXPORT uint qHash(const QJsonObject &object, uint seed = 0);
 Q_CORE_EXPORT QDebug operator<<(QDebug, const QJsonObject &);
 #endif
 
+#ifndef QT_NO_DATASTREAM
+Q_CORE_EXPORT QDataStream &operator<<(QDataStream &, const QJsonObject &);
+Q_CORE_EXPORT QDataStream &operator>>(QDataStream &, QJsonObject &);
+#endif
+
 QT_END_NAMESPACE
 
 #endif // QJSONOBJECT_H

tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp

@@ -1822,7 +1822,6 @@ DECLARE_NONSTREAMABLE(void*)
 DECLARE_NONSTREAMABLE(QModelIndex)
 DECLARE_NONSTREAMABLE(QPersistentModelIndex)
 DECLARE_NONSTREAMABLE(QJsonValue)
-DECLARE_NONSTREAMABLE(QJsonObject)
 DECLARE_NONSTREAMABLE(QCborValue)
 DECLARE_NONSTREAMABLE(QCborArray)
 DECLARE_NONSTREAMABLE(QCborMap)

tests/auto/corelib/serialization/json/tst_qtjson.cpp

@@ -157,6 +157,8 @@ private Q_SLOTS:
     void streamSerializationQJsonDocument();
     void streamSerializationQJsonArray_data();
     void streamSerializationQJsonArray();
+    void streamSerializationQJsonObject_data();
+    void streamSerializationQJsonObject();
     void streamVariantSerialization();
 
 private:
@@ -3059,6 +3061,27 @@ void tst_QtJson::streamSerializationQJsonArray()
     QCOMPARE(output, array);
 }
 
+void tst_QtJson::streamSerializationQJsonObject_data()
+{
+    QTest::addColumn<QJsonObject>("object");
+    QTest::newRow("empty") << QJsonObject();
+    QTest::newRow("non-empty") << QJsonObject{{"foo", 665}, {"bar", 666}};
+}
+
+void tst_QtJson::streamSerializationQJsonObject()
+{
+    // Check interface only, implementation is tested through to and from
+    // json functions.
+    QByteArray buffer;
+    QFETCH(QJsonObject, object);
+    QJsonObject output;
+    QDataStream save(&buffer, QIODevice::WriteOnly);
+    save << object;
+    QDataStream load(buffer);
+    load >> output;
+    QCOMPARE(output, object);
+}
+
 void tst_QtJson::streamVariantSerialization()
 {
     // Check interface only, implementation is tested through to and from
@@ -3086,6 +3109,17 @@ void tst_QtJson::streamVariantSerialization()
         QCOMPARE(output.userType(), QMetaType::QJsonArray);
         QCOMPARE(output.toJsonArray(), array);
     }
+    {
+        QJsonObject obj{{"foo", 42}};
+        QVariant output;
+        QVariant variant(obj);
+        QDataStream save(&buffer, QIODevice::WriteOnly);
+        save << variant;
+        QDataStream load(buffer);
+        load >> output;
+        QCOMPARE(output.userType(), QMetaType::QJsonObject);
+        QCOMPARE(output.toJsonObject(), obj);
+    }
 }
 
 QTEST_MAIN(tst_QtJson)

tests/auto/corelib/serialization/qdatastream/tst_qdatastream.cpp

@@ -137,6 +137,7 @@ private slots:
 
     void stream_QJsonDocument();
     void stream_QJsonArray();
+    void stream_QJsonObject();
 
     void setVersion_data();
     void setVersion();
@@ -2146,6 +2147,30 @@ void tst_QDataStream::stream_QJsonArray()
     }
 }
 
+void tst_QDataStream::stream_QJsonObject()
+{
+    QByteArray buffer;
+    {
+        QDataStream save(&buffer, QIODevice::WriteOnly);
+        save << QByteArrayLiteral("invalidJson");
+        QDataStream load(&buffer, QIODevice::ReadOnly);
+        QJsonObject object;
+        load >> object;
+        QVERIFY(object.isEmpty());
+        QVERIFY(load.status() != QDataStream::Ok);
+        QCOMPARE(load.status(), QDataStream::ReadCorruptData);
+    }
+    {
+        QDataStream save(&buffer, QIODevice::WriteOnly);
+        QJsonObject objSave{{"foo", 1}, {"bar", 2}};
+        save << objSave;
+        QDataStream load(&buffer, QIODevice::ReadOnly);
+        QJsonObject objLoad;
+        load >> objLoad;
+        QCOMPARE(objLoad, objSave);
+    }
+}
+
 void tst_QDataStream::setVersion_data()
 {
     QTest::addColumn<int>("vers");