Support short and narrow formats for format_timedelta(..., add_direction=True)

Fixes #1162

Author: akx

babel/dates.py

@@ -943,11 +943,16 @@ def format_timedelta(
 
     def _iter_patterns(a_unit):
         if add_direction:
-            unit_rel_patterns = locale._data['date_fields'][a_unit]
-            if seconds >= 0:
-                yield unit_rel_patterns['future']
-            else:
-                yield unit_rel_patterns['past']
+            for key in (f"{a_unit}-{format}", a_unit):
+                unit_rel_patterns = locale._data['date_fields'].get(key)
+                if not unit_rel_patterns:
+                    continue
+                if seconds >= 0:
+                    yield unit_rel_patterns['future']
+                    break  # do not try fallback key
+                else:
+                    yield unit_rel_patterns['past']
+                    break  # do not try fallback key
         a_unit = f"duration-{a_unit}"
         unit_pats = locale._data['unit_patterns'].get(a_unit, {})
         yield unit_pats.get(format)

tests/test_dates.py

@@ -807,3 +807,24 @@ def test_issue_892():
 def test_issue_1089():
     assert dates.format_datetime(datetime.now(), locale="ja_JP@mod")
     assert dates.format_datetime(datetime.now(), locale=Locale.parse("ja_JP@mod"))
+
+
+@pytest.mark.parametrize(('locale', 'format', 'negative', 'expected'), [
+    ('en_US', 'long', False, 'in 3 hours'),
+    ('en_US', 'long', True, '3 hours ago'),
+    ('en_US', 'narrow', False, 'in 3h'),
+    ('en_US', 'narrow', True, '3h ago'),
+    ('en_US', 'short', False, 'in 3 hr.'),
+    ('en_US', 'short', True, '3 hr. ago'),
+    ('fi_FI', 'long', False, '3 tunnin päästä'),
+    ('fi_FI', 'long', True, '3 tuntia sitten'),
+    ('fi_FI', 'short', False, '3 t päästä'),
+    ('fi_FI', 'short', True, '3 t sitten'),
+    ('sv_SE', 'long', False, 'om 3 timmar'),
+    ('sv_SE', 'long', True, 'för 3 timmar sedan'),
+    ('sv_SE', 'short', False, 'om 3 tim'),
+    ('sv_SE', 'short', True, 'för 3 tim sedan'),
+])
+def test_issue_1162(locale, format, negative, expected):
+    delta = timedelta(seconds=10800) * (-1 if negative else +1)
+    assert dates.format_timedelta(delta, add_direction=True, format=format, locale=locale) == expected