Files
langgraph/libs/langgraph/tests/test_channels.py
T
Sydney RunkleandGitHub 2d3121a17c chore: drop Python 3.9 (and syntax) (#6289)
* `strict=False` is the default, pyupgrade to min version 3.10 adds this
to be explicit w/ behavior
2025-10-16 20:17:46 -04:00

90 lines
2.9 KiB
Python

import operator
from collections.abc import Sequence
import pytest
from langgraph._internal._typing import MISSING
from langgraph.channels.binop import BinaryOperatorAggregate
from langgraph.channels.last_value import LastValue
from langgraph.channels.topic import Topic
from langgraph.errors import EmptyChannelError, InvalidUpdateError
pytestmark = pytest.mark.anyio
def test_last_value() -> None:
channel = LastValue(int).from_checkpoint(MISSING)
assert channel.ValueType is int
assert channel.UpdateType is int
with pytest.raises(EmptyChannelError):
channel.get()
with pytest.raises(InvalidUpdateError):
channel.update([5, 6])
channel.update([3])
assert channel.get() == 3
channel.update([4])
assert channel.get() == 4
checkpoint = channel.checkpoint()
channel = LastValue(int).from_checkpoint(checkpoint)
assert channel.get() == 4
def test_topic() -> None:
channel = Topic(str).from_checkpoint(MISSING)
assert channel.ValueType == Sequence[str]
assert channel.UpdateType == str | list[str]
assert channel.update(["a", "b"])
assert channel.get() == ["a", "b"]
assert channel.update([["c", "d"], "d"])
assert channel.get() == ["c", "d", "d"]
assert channel.update([])
with pytest.raises(EmptyChannelError):
channel.get()
assert not channel.update([]), "channel already empty"
assert channel.update(["e"])
assert channel.get() == ["e"]
checkpoint = channel.checkpoint()
channel = Topic(str).from_checkpoint(checkpoint)
assert channel.get() == ["e"]
channel_copy = Topic(str).from_checkpoint(checkpoint)
channel_copy.update(["f"])
assert channel_copy.get() == ["f"]
assert channel.get() == ["e"]
def test_topic_accumulate() -> None:
channel = Topic(str, accumulate=True).from_checkpoint(MISSING)
assert channel.ValueType == Sequence[str]
assert channel.UpdateType == str | list[str]
assert channel.update(["a", "b"])
assert channel.get() == ["a", "b"]
assert channel.update(["b", ["c", "d"], "d"])
assert channel.get() == ["a", "b", "b", "c", "d", "d"]
assert not channel.update([])
assert channel.get() == ["a", "b", "b", "c", "d", "d"]
checkpoint = channel.checkpoint()
channel = Topic(str, accumulate=True).from_checkpoint(checkpoint)
assert channel.get() == ["a", "b", "b", "c", "d", "d"]
assert channel.update(["e"])
assert channel.get() == ["a", "b", "b", "c", "d", "d", "e"]
def test_binop() -> None:
channel = BinaryOperatorAggregate(int, operator.add).from_checkpoint(MISSING)
assert channel.ValueType is int
assert channel.UpdateType is int
assert channel.get() == 0
channel.update([1, 2, 3])
assert channel.get() == 6
channel.update([4])
assert channel.get() == 10
checkpoint = channel.checkpoint()
channel = BinaryOperatorAggregate(int, operator.add).from_checkpoint(checkpoint)
assert channel.get() == 10