1 files changed, 56 insertions, 0 deletions
diff --git a/botcore/utils/members.py b/botcore/utils/members.py
new file mode 100644
index 00000000..e89b4618
--- /dev/null
+++ b/botcore/utils/members.py
@@ -0,0 +1,56 @@
+"""Useful helper functions for interactin with :obj:`discord.Member` objects."""
+
+import typing
+
+import discord
+
+from botcore.utils import logging
+
+log = logging.get_logger(__name__)
+
+
+async def get_or_fetch_member(guild: discord.Guild, member_id: int) -> typing.Optional[discord.Member]:
+    """
+    Attempt to get a member from cache; on failure fetch from the API.
+
+    Returns:
+        The :obj:`discord.Member` or :obj:`None` to indicate the member could not be found.
+    """
+    if member := guild.get_member(member_id):
+        log.trace(f"{member} retrieved from cache.")
+    else:
+        try:
+            member = await guild.fetch_member(member_id)
+        except discord.errors.NotFound:
+            log.trace(f"Failed to fetch {member_id} from API.")
+            return None
+        log.trace(f"{member} fetched from API.")
+    return member
+
+
+async def handle_role_change(
+    member: discord.Member,
+    coro: typing.Callable[..., typing.Coroutine],
+    role: discord.Role
+) -> None:
+    """
+    Await the given ``coro`` with ``member`` as the sole argument.
+
+    Handle errors that we expect to be raised from
+    :obj:`discord.Member.add_roles` and :obj:`discord.Member.remove_roles`.
+
+    Args:
+        member: The member to pass to ``coro``.
+        coro: This is intended to be :obj:`discord.Member.add_roles` or :obj:`discord.Member.remove_roles`.
+    """
+    try:
+        await coro(role)
+    except discord.NotFound:
+        log.error(f"Failed to change role for {member} ({member.id}): member not found")
+    except discord.Forbidden:
+        log.error(
+            f"Forbidden to change role for {member} ({member.id}); "
+            f"possibly due to role hierarchy"
+        )
+    except discord.HTTPException as e:
+        log.error(f"Failed to change role for {member} ({member.id}): {e.status} {e.code}")