hermes-agent/tests/agent/test_context_refs_concurrent.py
Kyzcreig 9c28600e77 test: prove concurrency with barriers/witnesses instead of wall-clock bounds
Replace OS-scheduler-dependent elapsed-time ceilings with deterministic
concurrency proofs in three tests:

- test_context_refs_concurrent: asyncio.Barrier rendezvous — all 3 URL
  fetches must be in flight simultaneously before any returns.
- test_memory_boundary_commit: positive non-blocking witness — the
  provider call list must still be empty when the async commit returns.
- test_mem0_v3 slow-prefetch: threading.Event park/release — prefetch
  must return while the backend search is still parked.

The tests/tools/test_mcp_tool.py hunk from the original PR is dropped:
main no longer carries the 'elapsed < 2.5' assertion it targeted
(superseded by a delay-relative bound).

Salvaged from #71913.
2026-07-29 21:30:53 -07:00

90 lines
3.9 KiB
Python

"""Tests for concurrent @-reference expansion in context_references.
test_refs_expand_concurrently asserts that N URL refs are fetched CONCURRENTLY.
It proves this with an asyncio.Barrier rendezvous rather than a stopwatch: all
N fetches must be in flight at the same instant before any is allowed to
return. On the serial `for ref in refs: await` loop the first fetch waits for
partners that never arrive and the test fails; with asyncio.gather it passes.
The output-contract test guards that concurrency does NOT change ordering,
warnings, blocks, or token accounting.
"""
from __future__ import annotations
import asyncio
import pytest
from agent.context_references import preprocess_context_references_async
async def _slow_fetcher(url: str) -> str:
# Simulate a per-URL network fetch (web_extract round trip).
await asyncio.sleep(0.2)
return f"CONTENT[{url}]"
@pytest.mark.asyncio
async def test_refs_expand_concurrently(tmp_path):
# Three independent URL refs in one message.
msg = "see @url:https://a.example/x @url:https://b.example/y @url:https://c.example/z please"
# Concurrency is proven by construction, not by measuring elapsed time.
#
# The old form asserted `elapsed < 0.4` ("well under 2x one 0.2s fetch").
# That makes the event-loop scheduler and any fixed setup part of the
# assertion: under a loaded CI box the inequality can flip with nothing
# wrong in the code under test, and the margin shrinks silently if setup
# cost is ever added ahead of dispatch.
#
# A barrier asserts the invariant directly: all THREE fetches must be
# inside the fetcher AT THE SAME TIME before any is allowed to return. If
# expansion ever goes serial the first fetch blocks waiting for partners
# that will not arrive, the barrier times out, and the test fails with an
# explicit message. No wall-clock constant, no load sensitivity.
N_REFS = 3
rendezvous = asyncio.Barrier(N_REFS)
entered: list[str] = []
overlapped = asyncio.Event()
async def barrier_fetcher(url: str) -> str:
entered.append(url)
# Generous relative to real scheduling latency (a rendezvous between
# already-dispatched coroutines needs milliseconds), but finite so a
# serial regression fails fast instead of hanging the suite.
async with asyncio.timeout(10):
await rendezvous.wait()
overlapped.set()
return f"CONTENT[{url}]"
try:
res = await preprocess_context_references_async(
msg, cwd=tmp_path, context_length=100_000, url_fetcher=barrier_fetcher,
)
except (asyncio.BrokenBarrierError, TimeoutError): # pragma: no cover - serial regression
pytest.fail(
"references did not expand concurrently: a fetch reached the "
f"rendezvous alone, so expansion never had {N_REFS} fetches in "
f"flight at once (entered: {entered})"
)
# The barrier only clears when all three fetches are in flight together.
assert overlapped.is_set(), f"references never overlapped (entered: {entered})"
assert len(entered) == N_REFS, f"expected {N_REFS} fetches, got {entered}"
# All three blocks present, in order.
assert res.expanded
body = res.message
assert body.index("a.example") < body.index("b.example") < body.index("c.example"), \
"reference blocks must stay in original order"
@pytest.mark.asyncio
async def test_concurrent_preserves_output_contract(tmp_path):
"""Concurrency must not change which blocks/warnings appear or their order."""
msg = "@url:https://one.example/p @url:https://two.example/q"
res = await preprocess_context_references_async(
msg, cwd=tmp_path, context_length=100_000, url_fetcher=_slow_fetcher,
)
assert "CONTENT[https://one.example/p]" in res.message
assert "CONTENT[https://two.example/q]" in res.message
assert res.message.index("one.example") < res.message.index("two.example")
assert res.injected_tokens > 0