add more tests

Author: theOehrly

lib/matplotlib/tests/test_dates.py

@@ -197,6 +197,18 @@ def test_RRuleLocator_dayrange():
     # On success, no overflow error shall be thrown
 
 
+def test_RRuleLocator_close_minmax():
+    # if d1 and d2 are very close together, rrule cannot create
+    # reasonable tick intervals; ensure that this is handled properly
+    rrule = mdates.rrulewrapper(dateutil.rrule.SECONDLY, interval=5)
+    loc = mdates.RRuleLocator(rrule)
+    d1 = datetime.datetime(year=2020, month=1, day=1)
+    d2 = datetime.datetime(year=2020, month=1, day=1, microsecond=1)
+    expected = ['2020-01-01 00:00:00+00:00',
+                '2020-01-01 00:00:00.000001+00:00']
+    assert list(map(str, mdates.num2date(loc.tick_values(d1, d2)))) == expected
+
+
 @image_comparison(['DateFormatter_fractionalSeconds.png'])
 def test_DateFormatter():
     import matplotlib.testing.jpl_units as units
@@ -991,6 +1003,10 @@ def _create_year_locator(date1, date2, **kwargs):
                  '2140-05-16 00:00:00+00:00', '2160-05-16 00:00:00+00:00',
                  '2180-05-16 00:00:00+00:00', '2200-05-16 00:00:00+00:00']
                 ],
+               [datetime.timedelta(weeks=52 * 5),
+                {'base': 20, 'month': 9, 'day': 25},
+                ['1980-09-25 00:00:00+00:00', '2000-09-25 00:00:00+00:00']
+                ],
                )
 
     for delta, arguments, expected in results: