diff --git a/src/xlsx/xlsxworkbook.cpp b/src/xlsx/xlsxworkbook.cpp
index e7fe00b..316e2f6 100755
--- a/src/xlsx/xlsxworkbook.cpp
+++ b/src/xlsx/xlsxworkbook.cpp
@@ -110,7 +110,6 @@ QString Workbook::defaultDateFormat() const
 {
     Q_D(const Workbook);
     return d->defaultDateFormat;
-
 }
 
 void Workbook::setDefaultDateFormat(const QString &format)
diff --git a/src/xlsx/xlsxworksheet.cpp b/src/xlsx/xlsxworksheet.cpp
index 94529b0..45e8fa7 100755
--- a/src/xlsx/xlsxworksheet.cpp
+++ b/src/xlsx/xlsxworksheet.cpp
@@ -206,6 +206,8 @@ Worksheet::Worksheet(const QString &name, Workbook *workbook) :
     d_ptr(new WorksheetPrivate(this))
 {
     d_ptr->name = name;
+    if (!workbook) //For unit test propose only. Ignore the memery leak.
+        workbook = new Workbook;
     d_ptr->workbook = workbook;
 }
 
diff --git a/src/xlsx/xlsxworksheet.h b/src/xlsx/xlsxworksheet.h
index 8562534..e42036d 100755
--- a/src/xlsx/xlsxworksheet.h
+++ b/src/xlsx/xlsxworksheet.h
@@ -35,6 +35,7 @@ class QIODevice;
 class QDateTime;
 class QUrl;
 class QImage;
+class WorksheetTest;
 
 QT_BEGIN_NAMESPACE_XLSX
 class Package;
@@ -72,11 +73,6 @@ public:
     void setRightToLeft(bool enable);
     void setZeroValuesHidden(bool enable);
 
-    void saveToXmlFile(QIODevice *device);
-    QByteArray saveToXmlData();
-    bool loadFromXmlFile(QIODevice *device);
-    bool loadFromXmlData(const QByteArray &data);
-
     QString sheetName() const;
     void setSheetName(const QString &sheetName);
 
@@ -84,7 +80,13 @@ public:
 private:
     friend class Package;
     friend class Workbook;
-    Worksheet(const QString &sheetName, Workbook *book=0);
+    friend class WorksheetTest;
+    Worksheet(const QString &sheetName, Workbook *book);
+
+    void saveToXmlFile(QIODevice *device);
+    QByteArray saveToXmlData();
+    bool loadFromXmlFile(QIODevice *device);
+    bool loadFromXmlData(const QByteArray &data);
 
     virtual bool isChartsheet() const;
     bool isHidden() const;
diff --git a/tests/auto/auto.pro b/tests/auto/auto.pro
index fdd383d..3d711b2 100644
--- a/tests/auto/auto.pro
+++ b/tests/auto/auto.pro
@@ -1,7 +1,7 @@
 TEMPLATE=subdirs
 SUBDIRS=\
     utility \
-    mergecell \
+    worksheet \
     zipreader \
     relationships \
     propscore \
diff --git a/tests/auto/mergecell/tst_mergecelltest.cpp b/tests/auto/mergecell/tst_mergecelltest.cpp
deleted file mode 100644
index 93f4555..0000000
--- a/tests/auto/mergecell/tst_mergecelltest.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-#include <QBuffer>
-#include <QtTest>
-
-#include "xlsxworksheet.h"
-#include "xlsxdocument.h"
-
-class MergeCellTest : public QObject
-{
-    Q_OBJECT
-
-public:
-    MergeCellTest();
-
-private Q_SLOTS:
-    void testWithoutMerge();
-    void testMerge();
-    void testUnMerge();
-};
-
-MergeCellTest::MergeCellTest()
-{
-}
-
-void MergeCellTest::testWithoutMerge()
-{
-    QXlsx::Document xlsx;
-    xlsx.write("B1", "Hello");
-
-    QByteArray xmldata;
-    QBuffer buffer(&xmldata);
-    buffer.open(QIODevice::WriteOnly);
-    xlsx.currentWorksheet()->saveToXmlFile(&buffer);
-
-    QVERIFY2(!xmldata.contains("<mergeCell"), "");
-}
-
-void MergeCellTest::testMerge()
-{
-    QXlsx::Document xlsx;
-    xlsx.write("B1", "Test Merged Cell");
-    xlsx.mergeCells("B1:B5");
-
-    QByteArray xmldata;
-    QBuffer buffer(&xmldata);
-    buffer.open(QIODevice::WriteOnly);
-    xlsx.currentWorksheet()->saveToXmlFile(&buffer);
-
-    QVERIFY2(xmldata.contains("<mergeCells count=\"1\"><mergeCell ref=\"B1:B5\"/></mergeCells>"), "");
-}
-
-void MergeCellTest::testUnMerge()
-{
-    QXlsx::Document xlsx;
-    xlsx.write("B1", "Test Merged Cell");
-    xlsx.mergeCells("B1:B5");
-    xlsx.unmergeCells("B1:B5");
-
-    QByteArray xmldata;
-    QBuffer buffer(&xmldata);
-    buffer.open(QIODevice::WriteOnly);
-    xlsx.currentWorksheet()->saveToXmlFile(&buffer);
-
-    QVERIFY2(!xmldata.contains("<mergeCell"), "");
-}
-
-QTEST_APPLESS_MAIN(MergeCellTest)
-
-#include "tst_mergecelltest.moc"
diff --git a/tests/auto/worksheet/tst_worksheet.cpp b/tests/auto/worksheet/tst_worksheet.cpp
new file mode 100644
index 0000000..65b5f8c
--- /dev/null
+++ b/tests/auto/worksheet/tst_worksheet.cpp
@@ -0,0 +1,56 @@
+#include <QBuffer>
+#include <QtTest>
+
+#include "xlsxworksheet.h"
+
+class WorksheetTest : public QObject
+{
+    Q_OBJECT
+
+public:
+    WorksheetTest();
+
+private Q_SLOTS:
+    void testEmptySheet();
+    void testMerge();
+    void testUnMerge();
+};
+
+WorksheetTest::WorksheetTest()
+{
+}
+
+void WorksheetTest::testEmptySheet()
+{
+    QXlsx::Worksheet sheet("", 0);
+    sheet.write("B1", 123);
+    QByteArray xmldata = sheet.saveToXmlData();
+
+    QVERIFY2(!xmldata.contains("<mergeCell"), "");
+}
+
+void WorksheetTest::testMerge()
+{
+    QXlsx::Worksheet sheet("", 0);
+    sheet.write("B1", 123);
+    sheet.mergeCells("B1:B5");
+    QByteArray xmldata = sheet.saveToXmlData();
+
+    QVERIFY2(xmldata.contains("<mergeCells count=\"1\"><mergeCell ref=\"B1:B5\"/></mergeCells>"), "");
+}
+
+void WorksheetTest::testUnMerge()
+{
+    QXlsx::Worksheet sheet("", 0);
+    sheet.write("B1", 123);
+    sheet.mergeCells("B1:B5");
+    sheet.unmergeCells("B1:B5");
+
+    QByteArray xmldata = sheet.saveToXmlData();
+
+    QVERIFY2(!xmldata.contains("<mergeCell"), "");
+}
+
+QTEST_APPLESS_MAIN(WorksheetTest)
+
+#include "tst_worksheet.moc"
diff --git a/tests/auto/mergecell/mergecell.pro b/tests/auto/worksheet/worksheet.pro
similarity index 84%
rename from tests/auto/mergecell/mergecell.pro
rename to tests/auto/worksheet/worksheet.pro
index 640aa57..c4c578f 100644
--- a/tests/auto/mergecell/mergecell.pro
+++ b/tests/auto/worksheet/worksheet.pro
@@ -8,11 +8,11 @@ QT       += testlib xlsx xlsx-private
 CONFIG += testcase
 DEFINES += XLSX_TEST
 
-TARGET = tst_mergecelltest
+TARGET = tst_worksheet
 CONFIG   += console
 CONFIG   -= app_bundle
 
 TEMPLATE = app
 
-SOURCES += tst_mergecelltest.cpp
+SOURCES += tst_worksheet.cpp
 DEFINES += SRCDIR=\\\"$$PWD/\\\"