1 files changed, 251 insertions, 0 deletions
diff --git a/tests/datetime/test_sub.py b/tests/datetime/test_sub.py
new file mode 100644
index 0000000..1e51977
--- /dev/null
+++ b/tests/datetime/test_sub.py
@@ -0,0 +1,251 @@
+from __future__ import annotations
+
+from datetime import timedelta
+
+import pytest
+
+import pendulum
+
+from tests.conftest import assert_datetime
+
+
+def test_sub_years_positive():
+    assert pendulum.datetime(1975, 1, 1).subtract(years=1).year == 1974
+
+
+def test_sub_years_zero():
+    assert pendulum.datetime(1975, 1, 1).subtract(years=0).year == 1975
+
+
+def test_sub_years_negative():
+    assert pendulum.datetime(1975, 1, 1).subtract(years=-1).year == 1976
+
+
+def test_sub_months_positive():
+    assert pendulum.datetime(1975, 12, 1).subtract(months=1).month == 11
+
+
+def test_sub_months_zero():
+    assert pendulum.datetime(1975, 12, 1).subtract(months=0).month == 12
+
+
+def test_sub_months_negative():
+    assert pendulum.datetime(1975, 12, 1).subtract(months=-1).month == 1
+
+
+def test_sub_days_positive():
+    assert pendulum.datetime(1975, 5, 31).subtract(days=1).day == 30
+
+
+def test_sub_days_zero():
+    assert pendulum.datetime(1975, 5, 31).subtract(days=0).day == 31
+
+
+def test_sub_days_negative():
+    assert pendulum.datetime(1975, 5, 31).subtract(days=-1).day == 1
+
+
+def test_sub_weeks_positive():
+    assert pendulum.datetime(1975, 5, 21).subtract(weeks=1).day == 14
+
+
+def test_sub_weeks_zero():
+    assert pendulum.datetime(1975, 5, 21).subtract(weeks=0).day == 21
+
+
+def test_sub_weeks_negative():
+    assert pendulum.datetime(1975, 5, 21).subtract(weeks=-1).day == 28
+
+
+def test_sub_hours_positive():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(hours=1).hour == 23
+
+
+def test_sub_hours_zero():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(hours=0).hour == 0
+
+
+def test_sub_hours_negative():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(hours=-1).hour == 1
+
+
+def test_sub_minutes_positive():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(minutes=1).minute == 59
+
+
+def test_sub_minutes_zero():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(minutes=0).minute == 0
+
+
+def test_sub_minutes_negative():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(minutes=-1).minute == 1
+
+
+def test_sub_seconds_positive():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(seconds=1).second == 59
+
+
+def test_sub_seconds_zero():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(seconds=0).second == 0
+
+
+def test_sub_seconds_negative():
+    assert pendulum.datetime(1975, 5, 21, 0, 0, 0).subtract(seconds=-1).second == 1
+
+
+def test_subtract_timedelta():
+    delta = timedelta(days=6, seconds=16, microseconds=654321)
+    d = pendulum.datetime(2015, 3, 14, 3, 12, 15, 777777)
+
+    d = d - delta
+    assert d.day == 8
+    assert d.minute == 11
+    assert d.second == 59
+    assert d.microsecond == 123456
+
+
+def test_subtract_duration():
+    duration = pendulum.duration(
+        years=2, months=3, days=6, seconds=16, microseconds=654321
+    )
+    d = pendulum.datetime(2015, 3, 14, 3, 12, 15, 777777)
+
+    d = d - duration
+    assert d.year == 2012
+    assert d.month == 12
+    assert d.day == 8
+    assert d.hour == 3
+    assert d.minute == 11
+    assert d.second == 59
+    assert d.microsecond == 123456
+
+
+def test_subtract_time_to_new_transition_skipped():
+    dt = pendulum.datetime(2013, 3, 31, 3, 0, 0, 0, tz="Europe/Paris")
+
+    assert_datetime(dt, 2013, 3, 31, 3, 0, 0, 0)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 7200
+    assert dt.is_dst()
+
+    dt = dt.subtract(microseconds=1)
+
+    assert_datetime(dt, 2013, 3, 31, 1, 59, 59, 999999)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 3600
+    assert not dt.is_dst()
+
+    dt = pendulum.datetime(2013, 3, 10, 3, 0, 0, 0, tz="America/New_York")
+
+    assert_datetime(dt, 2013, 3, 10, 3, 0, 0, 0)
+    assert dt.timezone_name == "America/New_York"
+    assert dt.offset == -4 * 3600
+    assert dt.is_dst()
+
+    dt = dt.subtract(microseconds=1)
+
+    assert_datetime(dt, 2013, 3, 10, 1, 59, 59, 999999)
+    assert dt.timezone_name == "America/New_York"
+    assert dt.offset == -5 * 3600
+    assert not dt.is_dst()
+
+    dt = pendulum.datetime(1957, 4, 28, 3, 0, 0, 0, tz="America/New_York")
+
+    assert_datetime(dt, 1957, 4, 28, 3, 0, 0, 0)
+    assert dt.timezone_name == "America/New_York"
+    assert dt.offset == -4 * 3600
+    assert dt.is_dst()
+
+    dt = dt.subtract(microseconds=1)
+
+    assert_datetime(dt, 1957, 4, 28, 1, 59, 59, 999999)
+    assert dt.timezone_name == "America/New_York"
+    assert dt.offset == -5 * 3600
+    assert not dt.is_dst()
+
+
+def test_subtract_time_to_new_transition_skipped_big():
+    dt = pendulum.datetime(2013, 3, 31, 3, 0, 0, 0, tz="Europe/Paris")
+
+    assert_datetime(dt, 2013, 3, 31, 3, 0, 0, 0)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 7200
+    assert dt.is_dst()
+
+    dt = dt.subtract(days=1)
+
+    assert_datetime(dt, 2013, 3, 30, 3, 0, 0, 0)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 3600
+    assert not dt.is_dst()
+
+
+def test_subtract_time_to_new_transition_repeated():
+    dt = pendulum.datetime(2013, 10, 27, 2, 0, 0, 0, tz="Europe/Paris")
+
+    assert_datetime(dt, 2013, 10, 27, 2, 0, 0, 0)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 3600
+    assert not dt.is_dst()
+
+    dt = dt.subtract(microseconds=1)
+
+    assert_datetime(dt, 2013, 10, 27, 2, 59, 59, 999999)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 7200
+    assert dt.is_dst()
+
+    dt = pendulum.datetime(2013, 11, 3, 1, 0, 0, 0, tz="America/New_York")
+
+    assert_datetime(dt, 2013, 11, 3, 1, 0, 0, 0)
+    assert dt.timezone_name == "America/New_York"
+    assert dt.offset == -5 * 3600
+    assert not dt.is_dst()
+
+    dt = dt.subtract(microseconds=1)
+
+    assert_datetime(dt, 2013, 11, 3, 1, 59, 59, 999999)
+    assert dt.timezone_name == "America/New_York"
+    assert dt.offset == -4 * 3600
+    assert dt.is_dst()
+
+
+def test_subtract_time_to_new_transition_repeated_big():
+    dt = pendulum.datetime(2013, 10, 27, 2, 0, 0, 0, tz="Europe/Paris")
+
+    assert_datetime(dt, 2013, 10, 27, 2, 0, 0, 0)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 3600
+    assert not dt.is_dst()
+
+    dt = dt.subtract(days=1)
+
+    assert_datetime(dt, 2013, 10, 26, 2, 0, 0, 0)
+    assert dt.timezone_name == "Europe/Paris"
+    assert dt.offset == 7200
+    assert dt.is_dst()
+
+
+def test_subtract_invalid_type():
+    d = pendulum.datetime(1975, 5, 21, 0, 0, 0)
+
+    with pytest.raises(TypeError):
+        d - "ab"
+
+    with pytest.raises(TypeError):
+        "ab" - d
+
+
+def test_subtract_negative_over_dls_transitioning_off():
+    just_before_dls_ends = pendulum.datetime(
+        2019, 11, 3, 1, 30, tz="US/Pacific", fold=0
+    )
+    plus_10_hours = just_before_dls_ends + timedelta(hours=10)
+    minus_neg_10_hours = just_before_dls_ends - timedelta(hours=-10)
+
+    # 1:30-0700 becomes 10:30-0800
+    assert plus_10_hours.hour == 10
+    assert minus_neg_10_hours.hour == 10
+    assert just_before_dls_ends.is_dst()
+    assert not plus_10_hours.is_dst()
+    assert not minus_neg_10_hours.is_dst()