Fix failing duration conversion

https://github.com/python-discord/bot/issues/446

The current ExpirationDate converter does not convert duration strings
to `datetime.datetime` objects correctly. To remedy the problem, I've
written a new Duration converter that uses regex matching to extract
the relevant duration units and `dateutil.relativedelta.relativedelta`
to compute a `datetime.datetime` that's the given duration in the
future.

I've left the old `ExpirationDate` converter in place for now, since
the new Duration converter may not be the most optimal method. However,
given the importance of being able to convert durations for moderation
tasks, I think it's better to implement Duration now and rethink the
approach later.

This commit closes #446

1 files changed, 4 insertions, 4 deletions

diff --git a/bot/cogs/reminders.py b/bot/cogs/reminders.py
index 8460de91f..c37abf21e 100644
--- a/bot/cogs/reminders.py
+++ b/bot/cogs/reminders.py
@@ -11,7 +11,7 @@ from discord import Colour, Embed, Message
 from discord.ext.commands import Bot, Cog, Context, group
 
 from bot.constants import Channels, Icons, NEGATIVE_REPLIES, POSITIVE_REPLIES, STAFF_ROLES
-from bot.converters import ExpirationDate
+from bot.converters import Duration
 from bot.pagination import LinePaginator
 from bot.utils.checks import without_role_check
 from bot.utils.scheduling import Scheduler
@@ -118,12 +118,12 @@ class Reminders(Scheduler, Cog):
         await self._delete_reminder(reminder["id"])
 
     @group(name="remind", aliases=("reminder", "reminders"), invoke_without_command=True)
-    async def remind_group(self, ctx: Context, expiration: ExpirationDate, *, content: str) -> None:
+    async def remind_group(self, ctx: Context, expiration: Duration, *, content: str) -> None:
         """Commands for managing your reminders."""
         await ctx.invoke(self.new_reminder, expiration=expiration, content=content)
 
     @remind_group.command(name="new", aliases=("add", "create"))
-    async def new_reminder(self, ctx: Context, expiration: ExpirationDate, *, content: str) -> Optional[Message]:
+    async def new_reminder(self, ctx: Context, expiration: Duration, *, content: str) -> Optional[Message]:
         """
         Set yourself a simple reminder.
 
@@ -237,7 +237,7 @@ class Reminders(Scheduler, Cog):
         await ctx.invoke(self.bot.get_command("help"), "reminders", "edit")
 
     @edit_reminder_group.command(name="duration", aliases=("time",))
-    async def edit_reminder_duration(self, ctx: Context, id_: int, expiration: ExpirationDate) -> None:
+    async def edit_reminder_duration(self, ctx: Context, id_: int, expiration: Duration) -> None:
         """
          Edit one of your reminder's expiration.