TST: Add unittest for .xls file

unittests/test_table_importer.py

@@ -77,7 +77,8 @@ class ConverterTest(unittest.TestCase):
         # TODO datatypes are different; fix it
         assert df.d.iloc[0] == datetime.datetime(1980, 12, 31, 13, 24, 23)
 
-    def test_date(self):
+    def test_date_xlsx(self):
+        """Test with .xlsx in order to check openpyxl engine."""
         test_file = os.path.join(os.path.dirname(__file__), "date.xlsx")
         self.importer = XLSImporter(converters={'a': date_converter,
                                                 'b': date_converter,
@@ -91,6 +92,21 @@ class ConverterTest(unittest.TestCase):
         assert df.shape[0] == 2
         assert df.a.iloc[0] == df.b.iloc[0] == df.c.iloc[0]
 
+    def test_date_xls(self):
+        """Test with .xlsx in order to check xlrd engine."""
+        test_file = os.path.join(os.path.dirname(__file__), "date.xls")
+        self.importer = XLSImporter(converters={'a': date_converter,
+                                                'b': date_converter,
+                                                'c': partial(date_converter,
+                                                             fmt="%d.%m.%y")
+                                                }, obligatory_columns=['a'])
+
+        xls_file = pd.io.excel.ExcelFile(test_file)
+        df = xls_file.parse()
+        df = self.importer.read_xls(test_file)
+        assert df.shape[0] == 2
+        assert df.a.iloc[0] == df.b.iloc[0] == df.c.iloc[0]
+
     def test_inc_date(self):
         incomplete_date_converter("2020", fmts={"%Y": "%Y"}) == "2020"
         incomplete_date_converter("02/2020",