TST: reorganize misplaced year / business year tests (pandas-dev#27085)…

… (pandas-dev#42930)

pandas/tests/tseries/offsets/test_business_year.py

@@ -0,0 +1,220 @@
+"""
+Tests for the following offsets:
+- BYearBegin
+- BYearEnd
+"""
+from datetime import datetime
+
+import pytest
+
+from pandas.tests.tseries.offsets.common import (
+    Base,
+    assert_is_on_offset,
+    assert_offset_equal,
+)
+
+from pandas.tseries.offsets import (
+    BYearBegin,
+    BYearEnd,
+)
+
+
+class TestBYearBegin(Base):
+    _offset = BYearBegin
+
+    def test_misspecified(self):
+        msg = "Month must go from 1 to 12"
+        with pytest.raises(ValueError, match=msg):
+            BYearBegin(month=13)
+        with pytest.raises(ValueError, match=msg):
+            BYearEnd(month=13)
+
+    offset_cases = []
+    offset_cases.append(
+        (
+            BYearBegin(),
+            {
+                datetime(2008, 1, 1): datetime(2009, 1, 1),
+                datetime(2008, 6, 30): datetime(2009, 1, 1),
+                datetime(2008, 12, 31): datetime(2009, 1, 1),
+                datetime(2011, 1, 1): datetime(2011, 1, 3),
+                datetime(2011, 1, 3): datetime(2012, 1, 2),
+                datetime(2005, 12, 30): datetime(2006, 1, 2),
+                datetime(2005, 12, 31): datetime(2006, 1, 2),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearBegin(0),
+            {
+                datetime(2008, 1, 1): datetime(2008, 1, 1),
+                datetime(2008, 6, 30): datetime(2009, 1, 1),
+                datetime(2008, 12, 31): datetime(2009, 1, 1),
+                datetime(2005, 12, 30): datetime(2006, 1, 2),
+                datetime(2005, 12, 31): datetime(2006, 1, 2),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearBegin(-1),
+            {
+                datetime(2007, 1, 1): datetime(2006, 1, 2),
+                datetime(2009, 1, 4): datetime(2009, 1, 1),
+                datetime(2009, 1, 1): datetime(2008, 1, 1),
+                datetime(2008, 6, 30): datetime(2008, 1, 1),
+                datetime(2008, 12, 31): datetime(2008, 1, 1),
+                datetime(2006, 12, 29): datetime(2006, 1, 2),
+                datetime(2006, 12, 30): datetime(2006, 1, 2),
+                datetime(2006, 1, 1): datetime(2005, 1, 3),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearBegin(-2),
+            {
+                datetime(2007, 1, 1): datetime(2005, 1, 3),
+                datetime(2007, 6, 30): datetime(2006, 1, 2),
+                datetime(2008, 12, 31): datetime(2007, 1, 1),
+            },
+        )
+    )
+
+    @pytest.mark.parametrize("case", offset_cases)
+    def test_offset(self, case):
+        offset, cases = case
+        for base, expected in cases.items():
+            assert_offset_equal(offset, base, expected)
+
+
+class TestBYearEnd(Base):
+    _offset = BYearEnd
+
+    offset_cases = []
+    offset_cases.append(
+        (
+            BYearEnd(),
+            {
+                datetime(2008, 1, 1): datetime(2008, 12, 31),
+                datetime(2008, 6, 30): datetime(2008, 12, 31),
+                datetime(2008, 12, 31): datetime(2009, 12, 31),
+                datetime(2005, 12, 30): datetime(2006, 12, 29),
+                datetime(2005, 12, 31): datetime(2006, 12, 29),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearEnd(0),
+            {
+                datetime(2008, 1, 1): datetime(2008, 12, 31),
+                datetime(2008, 6, 30): datetime(2008, 12, 31),
+                datetime(2008, 12, 31): datetime(2008, 12, 31),
+                datetime(2005, 12, 31): datetime(2006, 12, 29),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearEnd(-1),
+            {
+                datetime(2007, 1, 1): datetime(2006, 12, 29),
+                datetime(2008, 6, 30): datetime(2007, 12, 31),
+                datetime(2008, 12, 31): datetime(2007, 12, 31),
+                datetime(2006, 12, 29): datetime(2005, 12, 30),
+                datetime(2006, 12, 30): datetime(2006, 12, 29),
+                datetime(2007, 1, 1): datetime(2006, 12, 29),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearEnd(-2),
+            {
+                datetime(2007, 1, 1): datetime(2005, 12, 30),
+                datetime(2008, 6, 30): datetime(2006, 12, 29),
+                datetime(2008, 12, 31): datetime(2006, 12, 29),
+            },
+        )
+    )
+
+    @pytest.mark.parametrize("case", offset_cases)
+    def test_offset(self, case):
+        offset, cases = case
+        for base, expected in cases.items():
+            assert_offset_equal(offset, base, expected)
+
+    on_offset_cases = [
+        (BYearEnd(), datetime(2007, 12, 31), True),
+        (BYearEnd(), datetime(2008, 1, 1), False),
+        (BYearEnd(), datetime(2006, 12, 31), False),
+        (BYearEnd(), datetime(2006, 12, 29), True),
+    ]
+
+    @pytest.mark.parametrize("case", on_offset_cases)
+    def test_is_on_offset(self, case):
+        offset, dt, expected = case
+        assert_is_on_offset(offset, dt, expected)
+
+
+class TestBYearEndLagged(Base):
+    _offset = BYearEnd
+
+    def test_bad_month_fail(self):
+        msg = "Month must go from 1 to 12"
+        with pytest.raises(ValueError, match=msg):
+            BYearEnd(month=13)
+        with pytest.raises(ValueError, match=msg):
+            BYearEnd(month=0)
+
+    offset_cases = []
+    offset_cases.append(
+        (
+            BYearEnd(month=6),
+            {
+                datetime(2008, 1, 1): datetime(2008, 6, 30),
+                datetime(2007, 6, 30): datetime(2008, 6, 30),
+            },
+        )
+    )
+
+    offset_cases.append(
+        (
+            BYearEnd(n=-1, month=6),
+            {
+                datetime(2008, 1, 1): datetime(2007, 6, 29),
+                datetime(2007, 6, 30): datetime(2007, 6, 29),
+            },
+        )
+    )
+
+    @pytest.mark.parametrize("case", offset_cases)
+    def test_offset(self, case):
+        offset, cases = case
+        for base, expected in cases.items():
+            assert_offset_equal(offset, base, expected)
+
+    def test_roll(self):
+        offset = BYearEnd(month=6)
+        date = datetime(2009, 11, 30)
+
+        assert offset.rollforward(date) == datetime(2010, 6, 30)
+        assert offset.rollback(date) == datetime(2009, 6, 30)
+
+    on_offset_cases = [
+        (BYearEnd(month=2), datetime(2007, 2, 28), True),
+        (BYearEnd(month=6), datetime(2007, 6, 30), False),
+    ]
+
+    @pytest.mark.parametrize("case", on_offset_cases)
+    def test_is_on_offset(self, case):
+        offset, dt, expected = case
+        assert_is_on_offset(offset, dt, expected)