tests: Promote date_seq to testutil.

tests/test_reports_related_postings.py

@@ -27,13 +27,8 @@ from . import testutil
 from conservancy_beancount import data
 from conservancy_beancount.reports import core
 
-def date_seq(date=testutil.FY_MID_DATE, step=1):
-    while True:
-        yield date
-        date = date + datetime.timedelta(days=step)
-
 def accruals_and_payments(acct, src_acct, dst_acct, start_date, *amounts):
-    dates = date_seq(start_date)
+    dates = testutil.date_seq(start_date)
     for amt, currency in amounts:
         yield testutil.Transaction(date=next(dates), postings=[
             (acct, amt, currency),

tests/testutil.py

@@ -55,6 +55,11 @@ def combine_values(*value_seqs):
         stop,
     )
 
+def date_seq(date=FY_MID_DATE, step=1):
+    while True:
+        yield date
+        date += datetime.timedelta(days=step)
+
 def parse_date(s, fmt='%Y-%m-%d'):
     return datetime.datetime.strptime(s, fmt).date()