Deprecate maybeDeferred_coro(). (#7212)

scrapy/pipelines/__init__.py

@@ -16,7 +16,7 @@ from scrapy.exceptions import ScrapyDeprecationWarning
 from scrapy.middleware import MiddlewareManager
 from scrapy.utils.asyncio import is_asyncio_available
 from scrapy.utils.conf import build_component_list
-from scrapy.utils.defer import deferred_from_coro, ensure_awaitable, maybeDeferred_coro
+from scrapy.utils.defer import _maybeDeferred_coro, deferred_from_coro, ensure_awaitable
 from scrapy.utils.python import global_object_name
 
 if TYPE_CHECKING:
@@ -70,8 +70,8 @@ class ItemPipelineManager(MiddlewareManager):
             method: Callable[..., Coroutine[Any, Any, None] | Deferred[None] | None],
         ) -> Deferred[None]:
             if method in self._mw_methods_requiring_spider:
-                return maybeDeferred_coro(method, self._spider)
-            return maybeDeferred_coro(method)
+                return _maybeDeferred_coro(method, True, self._spider)
+            return _maybeDeferred_coro(method, True)
 
         dfds = [get_dfd(m) for m in methods]
         d: Deferred[list[tuple[bool, None]]] = DeferredList(

scrapy/utils/defer.py

@@ -419,6 +419,18 @@ def deferred_f_from_coro_f(
 
 def maybeDeferred_coro(
     f: Callable[_P, Any], *args: _P.args, **kw: _P.kwargs
+) -> Deferred[Any]:  # pragma: no cover
+    """Copy of defer.maybeDeferred that also converts coroutines to Deferreds."""
+    warnings.warn(
+        "maybeDeferred_coro() is deprecated and will be removed in a future Scrapy version.",
+        ScrapyDeprecationWarning,
+        stacklevel=2,
+    )
+    return _maybeDeferred_coro(f, False, *args, **kw)
+
+
+def _maybeDeferred_coro(
+    f: Callable[_P, Any], warn: bool, *args: _P.args, **kw: _P.kwargs
 ) -> Deferred[Any]:
     """Copy of defer.maybeDeferred that also converts coroutines to Deferreds."""
     try:
@@ -426,17 +438,28 @@ def maybeDeferred_coro(
     except:  # noqa: E722  # pylint: disable=bare-except
         return fail(failure.Failure(captureVars=Deferred.debug))
 
+    # when the deprecation period has ended we need to make sure the behavior
+    # of the public maybeDeferred_coro() function isn't changed, or drop it in
+    # the same release
     if isinstance(result, Deferred):
-        warnings.warn(
-            f"{global_object_name(f)} returned a Deferred, this is deprecated."
-            f" Please refactor this function to return a coroutine.",
-            ScrapyDeprecationWarning,
-            stacklevel=2,
-        )
+        if warn:
+            warnings.warn(
+                f"{global_object_name(f)} returned a Deferred, this is deprecated."
+                f" Please refactor this function to return a coroutine.",
+                ScrapyDeprecationWarning,
+                stacklevel=2,
+            )
         return result
     if asyncio.isfuture(result) or inspect.isawaitable(result):
         return deferred_from_coro(result)
     if isinstance(result, failure.Failure):
+        if warn:
+            warnings.warn(
+                f"{global_object_name(f)} returned a Failure, this is deprecated."
+                f" Please refactor this function to return a coroutine.",
+                ScrapyDeprecationWarning,
+                stacklevel=2,
+            )
         return fail(result)
     return succeed(result)
 

scrapy/utils/signal.py

@@ -22,9 +22,9 @@ from twisted.python.failure import Failure
 from scrapy.exceptions import ScrapyDeprecationWarning, StopDownload
 from scrapy.utils.asyncio import is_asyncio_available
 from scrapy.utils.defer import (
+    _maybeDeferred_coro,
     ensure_awaitable,
     maybe_deferred_to_future,
-    maybeDeferred_coro,
 )
 from scrapy.utils.log import failure_to_exc_info
 from scrapy.utils.python import global_object_name
@@ -114,8 +114,14 @@ def _send_catch_log_deferred(
     spider = named.get("spider")
     dfds: list[Deferred[tuple[TypingAny, TypingAny]]] = []
     for receiver in liveReceivers(getAllReceivers(sender, signal)):
-        d: Deferred[TypingAny] = maybeDeferred_coro(
-            robustApply, receiver, signal=signal, sender=sender, *arguments, **named
+        d: Deferred[TypingAny] = _maybeDeferred_coro(
+            robustApply,
+            True,
+            receiver,
+            signal=signal,
+            sender=sender,
+            *arguments,
+            **named,
         )
         d.addErrback(logerror, receiver)
         # TODO https://pylint.readthedocs.io/en/latest/user_guide/messages/warning/cell-var-from-loop.html