fix(history_iterator): messages repeat if before & after not set

[EmmmaTech]

Summary

fixes #1238, an issue introduced with the async iterator rewrite in 3.0 where messages would loop every 100 messages due to the after parameter never being updated. I also updated the documentation a bit to clarify this default behavior of the iterator since the original documentation never mentions it.

This is a Code Change

• I have tested my changes.
• I have updated the documentation to reflect the changes.
• I have run task pyright and fixed the relevant issues.

[teaishealthy]

I can't seem to get more than 100 messages

counter = 0
async for _ in channel.history(limit=200):
    counter += 1

print(counter)  # 100 (?)

[EmmmaTech]

this might be more than a fix now, it's a semi-refactor to try and more closely match the original discord.py behavior while fixing the desired result to fetch limit messages from the beginning of channel history. :p

[teaishealthy]

ran a few tests

master

❌ Failed for params: limit=None, before=None, after=None, around=None, oldest_first=False. Expected 150, got asyncio.TimeoutError.
✅ Passed for params: limit=50, before=None, after=None, around=None, oldest_first=False. Expected 50, got 50.
❌ Failed for params: limit=120, before=None, after=None, around=None, oldest_first=False. Expected 120, got duplicate messages found.
✅ Passed for params: limit=None, before=<message #130>, after=None, around=None, oldest_first=False. Expected 129, got 129.
✅ Passed for params: limit=150, before=<message #130>, after=None, around=None, oldest_first=False. Expected 129, got 129.
✅ Passed for params: limit=80, before=<message #130>, after=None, around=None, oldest_first=False. Expected 80, got 80.
✅ Passed for params: limit=None, before=None, after=<message #20>, around=None, oldest_first=True. Expected 130, got 130.
✅ Passed for params: limit=120, before=None, after=<message #20>, around=None, oldest_first=True. Expected 120, got 120.
✅ Passed for params: limit=50, before=None, after=<message #20>, around=None, oldest_first=True. Expected 50, got 50.
❌ Failed for params: limit=None, before=<message #130>, after=<message #20>, around=None, oldest_first=True. Expected 109, got 130.
✅ Passed for params: limit=75, before=<message #130>, after=<message #20>, around=None, oldest_first=True. Expected 75, got 75.
✅ Passed for params: limit=100, before=None, after=None, around=<message #75>, oldest_first=False. Expected around_test = lambda x: 100 <= x and x <= 101, got 100.
✅ Passed for params: limit=200, before=<message #130>, after=None, around=None, oldest_first=True. Expected 129, got 129.
✅ Passed for params: limit=200, before=None, after=<message #20>, around=None, oldest_first=False. Expected 130, got 130.
✅ Passed for params: limit=100, before=None, after=None, around=<message #75>, oldest_first=True. Expected around_test = lambda x: 100 <= x and x <= 101, got 100.
Successfully completed 12/15 tests.

EmmmaTech/fix/async-iterators

❌ Failed for params: limit=None, before=None, after=None, around=None, oldest_first=False. Expected 150, got 100.
✅ Passed for params: limit=50, before=None, after=None, around=None, oldest_first=False. Expected 50, got 50.
❌ Failed for params: limit=120, before=None, after=None, around=None, oldest_first=False. Expected 120, got 100.
✅ Passed for params: limit=None, before=<message #130>, after=None, around=None, oldest_first=False. Expected 129, got 129.
✅ Passed for params: limit=150, before=<message #130>, after=None, around=None, oldest_first=False. Expected 129, got 129.
✅ Passed for params: limit=80, before=<message #130>, after=None, around=None, oldest_first=False. Expected 80, got 80.
✅ Passed for params: limit=None, before=None, after=<message #20>, around=None, oldest_first=True. Expected 130, got 130.
✅ Passed for params: limit=120, before=None, after=<message #20>, around=None, oldest_first=True. Expected 120, got 120.
✅ Passed for params: limit=50, before=None, after=<message #20>, around=None, oldest_first=True. Expected 50, got 50.
✅ Passed for params: limit=None, before=<message #130>, after=<message #20>, around=None, oldest_first=True. Expected 109, got 109.
✅ Passed for params: limit=75, before=<message #130>, after=<message #20>, around=None, oldest_first=True. Expected 75, got 75.
✅ Passed for params: limit=100, before=None, after=None, around=<message #75>, oldest_first=False. Expected around_test = lambda x: 100 <= x and x <= 101, got 100.
✅ Passed for params: limit=200, before=<message #130>, after=None, around=None, oldest_first=True. Expected 129, got 129.
❌ Failed for params: limit=200, before=None, after=<message #20>, around=None, oldest_first=False. Expected 130, got 100.
✅ Passed for params: limit=100, before=None, after=None, around=<message #75>, oldest_first=True. Expected around_test = lambda x: 100 <= x and x <= 101, got 100.
Successfully completed 12/15 tests.

[teaishealthy]

oops accidentally closed this

[EmmmaTech]

could you share the testing code you used so I can locally test with my own changes? :>

[teaishealthy]

@EmmmaTech
https://gist.github.com/teaishealthy/7d46b6c0dfe8bf45e43208f4489fbaaf

make sure to configure the constants at the top of the file, then just call run_history_tests with a TextChannel

[teaishealthy]

fixed the limit pagination issue.

but: defaulting oldest_first=True changes the default iteration order of channel.history(limit=10) from the newest to the oldest messages. this also creates counterintuitive behavior when using before, as it now walks forward (oldest first) instead of backward from the anchor.