In months fix

pendulum/_extensions/_helpers.c

@@ -824,14 +824,6 @@ PyObject *precise_diff(PyObject *self, PyObject *args)
                 day_diff += days_in_last_month;
             }
         }
-        else if (day_diff == days_in_month - days_in_last_month)
-        {
-            // We have exactly a full month
-            // We remove the days difference
-            // and add one to the months difference
-            day_diff = 0;
-            month_diff += 1;
-        }
         else
         {
             // We have a full month

tests/date/test_diff.py

@@ -5,6 +5,19 @@
 import pendulum
 
 
+@pytest.fixture(autouse=True)
+def setup():
+    pendulum.set_local_timezone(pendulum.timezone("UTC"))
+
+    yield
+
+    pendulum.set_test_now()
+    pendulum.set_locale("en")
+    pendulum.set_local_timezone()
+    pendulum.week_starts_at(pendulum.MONDAY)
+    pendulum.week_ends_at(pendulum.SUNDAY)
+
+
 @pytest.fixture
 def today():
     return pendulum.today().date()
@@ -136,7 +149,7 @@ def test_diff_for_humans_now_and_month():
     with pendulum.test(pendulum.datetime(2017, 2, 28)):
         today = pendulum.today().date()
 
-        assert "1 month ago" == today.subtract(weeks=4).diff_for_humans()
+        assert "4 weeks ago" == today.subtract(weeks=4).diff_for_humans()
 
 
 def test_diff_for_humans_now_and_months(today):
@@ -189,7 +202,7 @@ def test_diff_for_humans_now_and_future_month():
     with pendulum.test(pendulum.datetime(2017, 3, 31)):
         today = pendulum.today().date()
 
-        assert "in 1 month" == today.add(months=1).diff_for_humans()
+        assert "in 4 weeks" == today.add(months=1).diff_for_humans()
 
     with pendulum.test(pendulum.datetime(2017, 4, 30)):
         today = pendulum.today().date()
@@ -199,7 +212,7 @@ def test_diff_for_humans_now_and_future_month():
     with pendulum.test(pendulum.datetime(2017, 1, 31)):
         today = pendulum.today().date()
 
-        assert "in 1 month" == today.add(weeks=4).diff_for_humans()
+        assert "in 4 weeks" == today.add(weeks=4).diff_for_humans()
 
 
 def test_diff_for_humans_now_and_future_months(today):
@@ -252,7 +265,7 @@ def test_diff_for_humans_other_and_month():
     with pendulum.test(pendulum.datetime(2017, 3, 31)):
         today = pendulum.today().date()
 
-        assert "1 month before" == today.diff_for_humans(today.add(months=1))
+        assert "4 weeks before" == today.diff_for_humans(today.add(months=1))
 
     with pendulum.test(pendulum.datetime(2017, 4, 30)):
         today = pendulum.today().date()
@@ -262,7 +275,7 @@ def test_diff_for_humans_other_and_month():
     with pendulum.test(pendulum.datetime(2017, 1, 31)):
         today = pendulum.today().date()
 
-        assert "1 month before" == today.diff_for_humans(today.add(weeks=4))
+        assert "4 weeks before" == today.diff_for_humans(today.add(weeks=4))
 
 
 def test_diff_for_humans_other_and_months(today):
@@ -315,7 +328,7 @@ def test_diff_for_humans_other_and_future_month():
     with pendulum.test(pendulum.datetime(2017, 2, 28)):
         today = pendulum.today().date()
 
-        assert "1 month after" == today.diff_for_humans(today.subtract(weeks=4))
+        assert "4 weeks after" == today.diff_for_humans(today.subtract(weeks=4))
 
 
 def test_diff_for_humans_other_and_future_months(today):

tests/duration/test_in_methods.py

@@ -1,3 +1,5 @@
+import pytest
+
 import pendulum
 
 
@@ -24,3 +26,27 @@ def test_in_minutes():
 def test_in_seconds():
     it = pendulum.duration(seconds=72)
     assert it.in_seconds() == 72
+
+
+@pytest.mark.parametrize("month", range(1, 13))
+def test_in_months_one_year_less_a_day(month):
+    start = pendulum.datetime(2022, month, 2).date()
+    end = pendulum.datetime(2023, month, 1).date()  # One year less a day
+    assert (end - start).in_months() == 11
+
+
+@pytest.mark.parametrize("month", range(1, 13))
+def test_in_months_one_year(month):
+    start = pendulum.datetime(2022, month, 1).date()
+    end = pendulum.datetime(2023, month, 1).date()  # One year exactly
+    assert (end - start).in_months() == 12
+
+
+@pytest.mark.parametrize("day", range(1, 29))
+def test_in_months_february(day):
+    start = pendulum.datetime(2022, 2, 4).date()
+    end_1 = pendulum.datetime(2023, 2, day).date()
+    end_2 = end_1.add(days=1)
+    m_diff_1 = (end_1 - start).in_months()
+    m_diff_2 = (end_2 - start).in_months()
+    assert m_diff_1 <= m_diff_2