updated some tests, added test for shrink, not working yet

pyfacts/pyfacts.py

@@ -81,6 +81,9 @@ def create_date_series(
             extend_by_days = 7 - end_date.weekday()
             end_date += relativedelta(days=extend_by_days)
 
+        else:
+            end_date += relativedelta(days=frequency.days)
+
         # TODO: Add code to ensure coverage for other frequencies as well
 
     datediff = (end_date - start_date).days / frequency.days + 1
@@ -91,7 +94,7 @@ def create_date_series(
         date = start_date + relativedelta(**diff)
 
         if eomonth:
-            replacement = {"month": date.month + 1} if date.month < 12 else {"year": date.year + 1}
+            replacement = {"month": date.month + 1} if date.month < 12 else {"year": date.year + 1, "month": 1}
             date = date.replace(day=1).replace(**replacement) - relativedelta(days=1)
 
         if date <= end_date:
@@ -846,8 +849,7 @@ class TimeSeries(TimeSeriesCore):
 
         dates = create_date_series(
             self.start_date,
-            self.end_date
-            + datetime.timedelta(to_frequency.days),  # need extra date at the end for calculation of last value
+            self.end_date,
             to_frequency.symbol,
             ensure_coverage=True,
         )

tests/conftest.py

@@ -3,10 +3,11 @@ import math
 import random
 from typing import List
 
-import pyfacts as pft
 import pytest
 from dateutil.relativedelta import relativedelta
 
+import pyfacts as pft
+
 
 def conf_add(n1, n2):
     return n1 + n2
@@ -95,7 +96,9 @@ def sample_data_generator(
         )
     }
     end_date = start_date + relativedelta(**timedelta_dict)
-    dates = pft.create_date_series(start_date, end_date, frequency.symbol, skip_weekends=skip_weekends, eomonth=eomonth)
+    dates = pft.create_date_series(
+        start_date, end_date, frequency.symbol, skip_weekends=skip_weekends, eomonth=eomonth, ensure_coverage=False
+    )
     if dates_as_string:
         dates = [dt.strftime("%Y-%m-%d") for dt in dates]
     values = create_prices(1000, mu, sigma, num)

tests/test_pyfacts.py

@@ -1,6 +1,7 @@
 import datetime
 
 import pytest
+
 from pyfacts import (
     AllFrequencies,
     Frequency,
@@ -340,8 +341,23 @@ class TestExpand:
 
 
 class TestShrink:
-    # TODO
-    pass
+    def test_daily_to_smaller(self, create_test_data):
+        ts_data = create_test_data(AllFrequencies.D, num=1000)
+        ts = TimeSeries(ts_data, "D")
+        shrunk_ts_w = ts.shrink("W", "ffill")
+        shrunk_ts_m = ts.shrink("M", "ffill")
+        assert len(shrunk_ts_w) == 143
+        assert len(shrunk_ts_m) == 34
+
+    def test_weekly_to_smaller(self, create_test_data):
+        ts_data = create_test_data(AllFrequencies.W, num=300)
+        ts = TimeSeries(ts_data, "W")
+        tsm = ts.shrink("M", "ffill")
+        assert len(tsm) == 70
+        tsmeo = ts.shrink("M", "ffill", eomonth=True)
+        assert len(tsmeo) == 69
+        with pytest.raises(ValueError):
+            ts.shrink("D", "ffill")
 
 
 class TestMeanReturns:
@@ -360,7 +376,7 @@ class TestTransform:
         ts = TimeSeries(ts_data, "D")
         tst = ts.transform("W", "mean")
         assert isinstance(tst, TimeSeries)
-        assert len(tst) == 157
+        assert len(tst) == 156
         assert "2017-01-30" in tst
         assert tst.iloc[4] == (datetime.datetime(2017, 1, 30), 1021.19)