interval: fix week arithmetic

Before this patch, weeks were ignored in Interval addition
and subtraction. This patch fixes the issue.

Author: DifferentialOrange

Diff for: CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+- `tarantool.Interval` arithmetic with weeks
+
 ## 1.1.0 - 2023-06-30
 
 ### Added

Diff for: tarantool/msgpack_ext/types/interval.py

@@ -145,6 +145,7 @@ def __add__(self, other):
         return Interval(
             year=self.year + other.year,
             month=self.month + other.month,
+            week=self.week + other.week,
             day=self.day + other.day,
             hour=self.hour + other.hour,
             minute=self.minute + other.minute,
@@ -194,6 +195,7 @@ def __sub__(self, other):
         return Interval(
             year=self.year - other.year,
             month=self.month - other.month,
+            week=self.week - other.week,
             day=self.day - other.day,
             hour=self.hour - other.hour,
             minute=self.minute - other.minute,

Diff for: test/suites/test_interval.py

@@ -283,6 +283,28 @@ def test_unknown_adjust_decode(self):
             'res_add': tarantool.Interval(year=3, adjust=tarantool.IntervalAdjust.LAST),
             'res_sub': tarantool.Interval(year=1, adjust=tarantool.IntervalAdjust.LAST),
         },
+        'weeks': {
+            'arg_1': tarantool.Interval(week=2),
+            'arg_2': tarantool.Interval(week=1),
+            'res_add': tarantool.Interval(week=3),
+            'res_sub': tarantool.Interval(week=1),
+        },
+        'date_with_week': {
+            'arg_1': tarantool.Interval(year=1, month=2, week=3, day=4),
+            'arg_2': tarantool.Interval(year=4, month=3, week=2, day=1),
+            'res_add': tarantool.Interval(year=5, month=5, week=5, day=5),
+            'res_sub': tarantool.Interval(year=-3, month=-1, week=1, day=3),
+        },
+        'datetime_with_week': {
+            'arg_1': tarantool.Interval(year=1, month=2, week=3, day=4, hour=1, minute=2,
+                                        sec=3000, nsec=10000000),
+            'arg_2': tarantool.Interval(year=2, month=1, week=-1, day=31, hour=-3, minute=0,
+                                        sec=1000, nsec=9876543),
+            'res_add': tarantool.Interval(year=3, month=3, week=2, day=35, hour=-2, minute=2,
+                                          sec=4000, nsec=19876543),
+            'res_sub': tarantool.Interval(year=-1, month=1, week=4, day=-27, hour=4, minute=2,
+                                          sec=2000, nsec=123457),
+        },
     }
 
     def test_python_interval_addition(self):