refactor(clients): read the stall window with a type check instead of a pyright ignore (#1498)

The only `pyright: ignore[reportArgumentType]` in `shelfmark/` is one I
added in #1426, and I was being lazy when I did. I hit the same error on
another PR and replaced the ignore there with a real check, so this does
the same for the original.

`_stall_window_seconds` reads the setting as an `object`. It now narrows
to int, float or str before calling `float()`, and a bad string falls
back to the default as before. A non-numeric value of another type
(None, a list) falls back to the default too, which used to happen
through a `TypeError`.

No behaviour change. The existing range test still passes and I added
`None` and a list to it. basedpyright is at 0 errors, ruff is clean and
the backend suite passes.

Co-authored-by: CaliBrain <calibrain@l4n.xyz>

shelfmark/download/clients/base_handler.py

@@ -273,10 +273,12 @@ class ExternalClientHandler(DownloadHandler, ABC):
     def _stall_window_seconds() -> float:
         """How long a torrent may go without progress, from the user's setting (seconds)."""
         raw = config.get(STALL_TIMEOUT_SETTING, STALL_TIMEOUT_DEFAULT_MINUTES)
-        try:
-            minutes = float(raw)  # pyright: ignore[reportArgumentType]
-        except TypeError, ValueError:
-            minutes = float(STALL_TIMEOUT_DEFAULT_MINUTES)
+        minutes = float(STALL_TIMEOUT_DEFAULT_MINUTES)
+        if isinstance(raw, (int, float, str)):
+            try:
+                minutes = float(raw)
+            except ValueError:
+                minutes = float(STALL_TIMEOUT_DEFAULT_MINUTES)
         if not math.isfinite(minutes):
             minutes = float(STALL_TIMEOUT_DEFAULT_MINUTES)
         minutes = min(max(minutes, STALL_TIMEOUT_MIN_MINUTES), STALL_TIMEOUT_MAX_MINUTES)

tests/download/test_torrent_queue_stall.py

@@ -229,6 +229,8 @@ def test_a_value_above_the_maximum_is_capped() -> None:
         (500, 3600.0),  # above the maximum
         ("soon", 900.0),  # not a number: the default
         ("", 900.0),
+        (None, 900.0),
+        ([5], 900.0),
         (float("nan"), 900.0),
         (float("inf"), 900.0),
     ],