1 files changed, 90 insertions, 0 deletions
diff --git a/tests/date/test_sub.py b/tests/date/test_sub.py
new file mode 100644
index 0000000..33855a4
--- /dev/null
+++ b/tests/date/test_sub.py
@@ -0,0 +1,90 @@
+from __future__ import annotations
+
+from datetime import datetime
+from datetime import timedelta
+
+import pytest
+
+import pendulum
+
+from tests.conftest import assert_date
+
+
+def test_subtract_years_positive():
+    assert pendulum.date(1975, 1, 1).subtract(years=1).year == 1974
+
+
+def test_subtract_years_zero():
+    assert pendulum.date(1975, 1, 1).subtract(years=0).year == 1975
+
+
+def test_subtract_years_negative():
+    assert pendulum.date(1975, 1, 1).subtract(years=-1).year == 1976
+
+
+def test_subtract_months_positive():
+    assert pendulum.date(1975, 1, 1).subtract(months=1).month == 12
+
+
+def test_subtract_months_zero():
+    assert pendulum.date(1975, 12, 1).subtract(months=0).month == 12
+
+
+def test_subtract_months_negative():
+    assert pendulum.date(1975, 11, 1).subtract(months=-1).month == 12
+
+
+def test_subtract_days_positive():
+    assert pendulum.Date(1975, 6, 1).subtract(days=1).day == 31
+
+
+def test_subtract_days_zero():
+    assert pendulum.Date(1975, 5, 31).subtract(days=0).day == 31
+
+
+def test_subtract_days_negative():
+    assert pendulum.Date(1975, 5, 30).subtract(days=-1).day == 31
+
+
+def test_subtract_days_max():
+    delta = pendulum.now() - pendulum.instance(datetime.min)
+    assert pendulum.now().subtract(days=delta.days - 1).year == 1
+
+
+def test_subtract_weeks_positive():
+    assert pendulum.Date(1975, 5, 28).subtract(weeks=1).day == 21
+
+
+def test_subtract_weeks_zero():
+    assert pendulum.Date(1975, 5, 21).subtract(weeks=0).day == 21
+
+
+def test_subtract_weeks_negative():
+    assert pendulum.Date(1975, 5, 14).subtract(weeks=-1).day == 21
+
+
+def test_subtract_timedelta():
+    delta = timedelta(days=18)
+    d = pendulum.date(2015, 3, 14)
+
+    new = d - delta
+    assert isinstance(new, pendulum.Date)
+    assert_date(new, 2015, 2, 24)
+
+
+def test_subtract_duration():
+    delta = pendulum.duration(years=2, months=3, days=18)
+    d = pendulum.date(2015, 3, 14)
+
+    new = d - delta
+    assert_date(new, 2012, 11, 26)
+
+
+def test_addition_invalid_type():
+    d = pendulum.date(2015, 3, 14)
+
+    with pytest.raises(TypeError):
+        d - "ab"
+
+    with pytest.raises(TypeError):
+        "ab" - d