Improve tests, add assertion for PeriodIndex as well

Author: sahildua2305

pandas/tests/frame/test_timeseries.py

@@ -325,10 +325,18 @@ def test_asfreq_datetimeindex(self):
 
     def test_asfreq_datetimeindex_empty_series(self):
         # GH 14340
-        empty = Series(index=pd.DatetimeIndex([])).asfreq('H')
-        normal = Series(index=pd.DatetimeIndex(["2016-09-29 11:00"]),
+
+        # DatetimeIndex
+        expected = Series(index=pd.DatetimeIndex(["2016-09-29 11:00"])).asfreq('H')
+        result = Series(index=pd.DatetimeIndex(["2016-09-29 11:00"]),
                         data=[3]).asfreq('H')
-        self.assertEqual(empty.index.freq, normal.index.freq)
+        self.assert_index_equal(expected.index, result.index)
+
+        # PeriodIndex
+        expected = Series(index=pd.PeriodIndex(['2011-1', '2011-2', '2011-3'], freq='M')).asfreq('M')
+        result = Series(index=pd.PeriodIndex(['2011-1', '2011-2', '2011-3'], freq='M'),
+                        data=[3]).asfreq('M')
+        self.assert_index_equal(expected.index, result.index)
 
     def test_first_last_valid(self):
         N = len(self.frame.index)