Handle discord.Forbidden 90001 errors by default in `create_task()` (#177)v9.7.0

Co-authored-by: Chris Lovering <[email protected]>

4 files changed, 55 insertions, 7 deletions

diff --git a/docs/changelog.rst b/docs/changelog.rst
index dda1012e..471f7be6 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -5,6 +5,7 @@ Changelog
 =========
 - :release:`9.7.0 <10th June 2023>`
 - :feature:`179` Add paste service utility to upload text to our paste service.
+- :feature:`177` Automatically handle discord.Forbidden 90001 errors in all schedules
 - :feature:`176` Migrate repo to use ruff for linting
 
 
diff --git a/pydis_core/utils/__init__.py b/pydis_core/utils/__init__.py
index 0ca265c9..ac5760a8 100644
--- a/pydis_core/utils/__init__.py
+++ b/pydis_core/utils/__init__.py
@@ -1,8 +1,8 @@
 """Useful utilities and tools for Discord bot development."""
 
 from pydis_core.utils import (
-    _monkey_patches, caching, channel, commands, cooldown, function, interactions, logging, members, paste_service,
-    regex, scheduling
+    _monkey_patches, caching, channel, commands, cooldown, error_handling, function, interactions, logging, members,
+    paste_service, regex, scheduling
 )
 from pydis_core.utils._extensions import unqualify
 
@@ -29,6 +29,7 @@ __all__ = [
     channel,
     commands,
     cooldown,
+    error_handling,
     function,
     interactions,
     logging,
diff --git a/pydis_core/utils/error_handling.py b/pydis_core/utils/error_handling.py
new file mode 100644
index 00000000..51d23ca0
--- /dev/null
+++ b/pydis_core/utils/error_handling.py
@@ -0,0 +1,35 @@
+from discord import Forbidden, Message
+
+from pydis_core.utils import logging
+
+log = logging.get_logger(__name__)
+
+
+async def handle_forbidden_from_block(error: Forbidden, message: Message | None = None) -> None:
+    """
+    Handles ``discord.Forbidden`` 90001 errors, or re-raises if ``error`` isn't a 90001 error.
+
+    Args:
+        error: The raised ``discord.Forbidden`` to check.
+        message: The message to reply to and include in logs, if error is 90001 and message is provided.
+    """
+    if error.code != 90001:
+        # The error ISN'T caused by the bot attempting to add a reaction
+        # to a message whose author has blocked the bot, so re-raise it
+        raise error
+
+    if not message:
+        log.info("Failed to add reaction(s) to a message since the message author has blocked the bot")
+        return
+
+    if message:
+        log.info(
+            "Failed to add reaction(s) to message %d-%d since the message author (%d) has blocked the bot",
+            message.channel.id,
+            message.id,
+            message.author.id,
+        )
+        await message.channel.send(
+            f":x: {message.author.mention} failed to add reaction(s) to your message as you've blocked me.",
+            delete_after=30
+        )
diff --git a/pydis_core/utils/scheduling.py b/pydis_core/utils/scheduling.py
index 1e2e25e7..aa90b1e1 100644
--- a/pydis_core/utils/scheduling.py
+++ b/pydis_core/utils/scheduling.py
@@ -8,7 +8,10 @@ from collections import abc
 from datetime import datetime, timezone
 from functools import partial
 
+from discord.errors import Forbidden
+
 from pydis_core.utils import logging
+from pydis_core.utils.error_handling import handle_forbidden_from_block
 
 _background_tasks: set[asyncio.Task] = set()
 
@@ -77,7 +80,7 @@ class Scheduler:
             coroutine.close()
             return
 
-        task = asyncio.create_task(coroutine, name=f"{self.name}_{task_id}")
+        task = asyncio.create_task(_coro_wrapper(coroutine), name=f"{self.name}_{task_id}")
         task.add_done_callback(partial(self._task_done_callback, task_id))
 
         self._scheduled_tasks[task_id] = task
@@ -238,9 +241,9 @@ def create_task(
         asyncio.Task: The wrapped task.
     """
     if event_loop is not None:
-        task = event_loop.create_task(coro, **kwargs)
+        task = event_loop.create_task(_coro_wrapper(coro), **kwargs)
     else:
-        task = asyncio.create_task(coro, **kwargs)
+        task = asyncio.create_task(_coro_wrapper(coro), **kwargs)
 
     _background_tasks.add(task)
     task.add_done_callback(_background_tasks.discard)
@@ -248,11 +251,19 @@ def create_task(
     return task
 
 
+async def _coro_wrapper(coro: abc.Coroutine[typing.Any, typing.Any, TASK_RETURN]) -> None:
+    """Wraps `coro` in a try/except block that will handle 90001 Forbidden errors."""
+    try:
+        await coro
+    except Forbidden as e:
+        await handle_forbidden_from_block(e)
+
+
 def _log_task_exception(task: asyncio.Task, *, suppressed_exceptions: tuple[type[Exception], ...]) -> None:
-    """Retrieve and log the exception raised in ``task`` if one exists."""
+    """Retrieve and log the exception raised in ``task``, if one exists and it's not suppressed."""
     with contextlib.suppress(asyncio.CancelledError):
         exception = task.exception()
-        # Log the exception if one exists.
+        # Log the exception if one exists and it's not suppressed/handled.
         if exception and not isinstance(exception, suppressed_exceptions):
             log = logging.get_logger(__name__)
             log.error(f"Error in task {task.get_name()} {id(task)}!", exc_info=exception)