fix(time): precisedelta keeps the sign of negative timedeltas

src/humanize/time.py

@@ -536,9 +536,21 @@ def precisedelta(
 
     ```
     """
+    # Sign captured from the ORIGINAL value: _date_and_delta returns
+    # _abs_timedelta(delta), which would silently drop it (#379).
+    import datetime as dt
+
+    if isinstance(value, dt.timedelta):
+        negative = value < dt.timedelta(0)
+    else:
+        try:
+            negative = value < 0
+        except TypeError:
+            negative = False
     date, delta = _date_and_delta(value, precise=True)
     if date is None:
         return str(value)
+    import datetime as dt
 
     suppress_set = {Unit[s.upper()] for s in suppress}
 
@@ -663,12 +675,12 @@ def precisedelta(
             break
 
     if len(texts) == 1:
-        return texts[0]
+        return ("-" if negative else "") + texts[0]
 
     head = ", ".join(texts[:-1])
     tail = texts[-1]
 
-    return _("%s and %s") % (head, tail)
+    return ("-" if negative else "") + _("%s and %s") % (head, tail)
 
 
 def _rounding_by_fmt(format: str, value: float) -> float | int:

tests/test_time.py

@@ -852,3 +852,29 @@ def test_time_unit() -> None:
 )
 def test_rounding_by_fmt(fmt: str, value: float, expected: float) -> None:
     assert time._rounding_by_fmt(fmt, value) == pytest.approx(expected)
+
+
+def test_precisedelta_negative_multi_unit():
+    """issue #379: precisedelta silently dropped the sign of negative timedeltas."""
+    assert (
+        humanize.precisedelta(dt.timedelta(seconds=-3661))
+        == "-1 hour, 1 minute and 1 second"
+    )
+
+
+def test_precisedelta_negative_single_unit():
+    assert (
+        humanize.precisedelta(dt.timedelta(seconds=-3661), minimum_unit="minutes")
+        == "-1 hour and 1.02 minutes"
+    )
+
+
+def test_precisedelta_zero_stays_unsigned():
+    assert humanize.precisedelta(dt.timedelta(0), minimum_unit="minutes") == "0 minutes"
+
+
+def test_precisedelta_positive_unchanged():
+    assert (
+        humanize.precisedelta(dt.timedelta(seconds=3661))
+        == "1 hour, 1 minute and 1 second"
+    )