feature: Add quarter unit to datetrunc (#17416)

Co-authored-by: John Bodley <john.bodley@airbnb.com>

superset-frontend/src/explore/components/controls/DateFilterControl/components/DateFunctionTooltip.tsx

@@ -62,7 +62,7 @@ dateadd(datetime("2020-03-01"), 2, day)`}</code>
       <h4>{t('Syntax')}</h4>
       <pre>
         <code>{`datetrunc([datetime], [dateunit])
-dateunit = (year | month | week)`}</code>
+dateunit = (year | quarter | month | week)`}</code>
       </pre>
       <h4>{t('Example')}</h4>
       <pre>

superset/utils/date_parser.py

@@ -21,6 +21,7 @@
 from time import struct_time
 from typing import Dict, List, Optional, Tuple
 
+import pandas as pd
 import parsedatetime
 from dateutil.parser import parse
 from dateutil.relativedelta import relativedelta
@@ -322,10 +323,12 @@ def eval(self) -> datetime:
             dttm = dttm.replace(
                 month=1, day=1, hour=0, minute=0, second=0, microsecond=0
             )
+        if unit == "quarter":
+            dttm = pd.Period(pd.Timestamp(dttm), freq="Q").to_timestamp()
         elif unit == "month":
             dttm = dttm.replace(day=1, hour=0, minute=0, second=0, microsecond=0)
         elif unit == "week":
-            dttm = dttm - relativedelta(days=dttm.weekday())
+            dttm -= relativedelta(days=dttm.weekday())
             dttm = dttm.replace(hour=0, minute=0, second=0, microsecond=0)
         elif unit == "day":
             dttm = dttm.replace(hour=0, minute=0, second=0, microsecond=0)
@@ -443,7 +446,7 @@ def datetime_parser() -> ParseResults:  # pylint: disable=too-many-locals
         + Group(
             date_expr
             + comma
-            + (YEAR | MONTH | WEEK | DAY | HOUR | MINUTE | SECOND)
+            + (YEAR | QUARTER | MONTH | WEEK | DAY | HOUR | MINUTE | SECOND)
             + ppOptional(comma)
         )
         + rparen

tests/integration_tests/utils/date_parser_tests.py

@@ -209,6 +209,10 @@ def test_datetime_eval(self):
         expected = datetime(2016, 1, 1, 0, 0, 0)
         self.assertEqual(result, expected)
 
+        result = datetime_eval("datetrunc(datetime('now'), quarter)")
+        expected = datetime(2016, 10, 1, 0, 0, 0)
+        self.assertEqual(result, expected)
+
         result = datetime_eval("datetrunc(datetime('now'), month)")
         expected = datetime(2016, 11, 1, 0, 0, 0)
         self.assertEqual(result, expected)