fix: warn_deprecated now respect warnings.filter ignores

changelog/1476.bugfix.rst

@@ -0,0 +1 @@
+Fix ``utils.warn_deprecated`` to respect :mod:`warnings` filters defined by user.

disnake/utils.py

@@ -301,8 +301,23 @@ def warn_deprecated(
         stacklevel = 1  # reset stacklevel, assume we just want the first frame outside library code
 
     old_filters = warnings.filters[:]
+    send_warning = True
+    if len(old_filters) > 0:
+        for action, _, category, module, _ in old_filters:
+            if (
+                (category is DeprecationWarning)
+                and ("disnake" in str(module))
+                and (action == "ignore")
+            ):
+                send_warning = False
+                break  # break out after first disnake rule, it's good enough.
+
+    # allow force bypassing of filters if the default DeprecationWarning ignore is set.
+    if not send_warning:
+        return
+
     try:
-        warnings.simplefilter("always", DeprecationWarning)
+        warnings.simplefilter(action="always", category=DeprecationWarning)
         warnings.warn(*args, stacklevel=stacklevel + 1, category=DeprecationWarning, **kwargs)
     finally:
         assert isinstance(warnings.filters, list)

tests/test_utils.py

@@ -127,6 +127,48 @@ def func(n: int) -> None:
     assert result[0].filename == mock.__file__
 
 
+@pytest.mark.parametrize(
+    "msg",
+    ["This is a deprecated function"],
+)
+def test_deprecated_warn(msg: str) -> None:
+    # Just test if works
+    # first clear existing filters - these will be restored at the end as this is probably messing with the global warning filters
+    filters = warnings.filters[:]
+
+    warnings.resetwarnings()
+    with warnings.catch_warnings(record=True) as result:
+        warnings.filterwarnings(
+            "always", category=DeprecationWarning, module=r"disnake\..*"
+        )  # this also works with just a plain str
+        utils.warn_deprecated(msg)
+
+    assert len(result) == 1
+    assert result[0].message.args[0] == msg  # pyright: ignore[reportAttributeAccessIssue]
+    assert result[0].category is DeprecationWarning
+
+    # Reset With empty filters - expected behaviour is that a warning is forced because it's empty
+    warnings.resetwarnings()
+    assert len(warnings.filters) == 0  # should be empty
+    with warnings.catch_warnings(record=True) as result:
+        utils.warn_deprecated(msg)
+
+    assert len(result) == 1
+    assert result[0].message.args[0] == msg  # pyright: ignore[reportAttributeAccessIssue]
+    assert result[0].category is DeprecationWarning
+
+    # Reset With empty filters - expected behaviour is that there is no warning because it's ignored
+    warnings.resetwarnings()
+    assert len(warnings.filters) == 0  # should be empty
+    with warnings.catch_warnings(record=True) as result:
+        warnings.filterwarnings("ignore", category=DeprecationWarning, module=r"disnake\..*")
+        utils.warn_deprecated(msg)
+
+    assert len(result) == 0
+
+    warnings.filters[:] = filters  # pyright: ignore[reportIndexIssue]
+
+
 @pytest.mark.parametrize(
     ("params", "expected"),
     [