Files
turnstone/tests/test_tool_truncation.py
T
Patrick Buckley 2dd0688d45 fix(compaction): carry the plan and the ask across compaction verbatim
The definition review found the two control-relevant crossings paraphrased:
the model's wind-down spill (recorded on the cooperative advisory, then
handed to the summarizer with everything else) and the user's last message
(clipped to 400 chars in the continuation hint). Both now cross copied.

- carry_spill: when the model stopped because it was advised to wrap up,
  its final turn's text is shell-concatenated onto the summary under
  '## Wind-down (verbatim)', ahead of '## Continue'. The summarizer still
  reads the spill; its paraphrase is no longer the only survivor.
- _carry_budget_chars(carries): ~25% of the window per carry, sized so ALL
  concurrent carries fit the spare after the summary output reserve —
  spill + hint fire together at the end-of-turn site, and independent
  sizing stacked reserve + 2*(cw/4) + margin past the window at default
  config. Floored at 2000 chars; oversize content keeps head + tail.
- _truncate_block's marker reports the original size ('truncated — N chars
  total'), and a truncated carry adds one line telling the model the full
  text remains in history and recall can retrieve it.
- Summary turns carry source="compaction" (in-memory swap and checkpoint
  reconstruction); _find_turn_boundaries and _generate_title test the tag
  instead of the label string, so a user who literally types
  '[Conversation summary]' stays a real turn.
- The send-loop overflow backstop now passes my_generation, closing the
  compact-and-swap race every other compaction site already guards.

Tests: tests/test_compaction_crossing.py (tags on both paths, literal-label
boundary, budget arithmetic incl. the double-carry invariant at shipped
defaults, verbatim/truncated carries, spill semantics, forwarding); existing
suites updated for the tagged label turns and the new kwargs.
2026-07-01 21:06:31 -07:00

247 lines
9.4 KiB
Python

"""Tests for capacity-aware tool output truncation and context overflow recovery."""
from __future__ import annotations
from unittest.mock import MagicMock, patch
import pytest
from turnstone.core.session import ChatSession
from turnstone.core.trajectory import turns_from_dicts
# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
@pytest.fixture
def session(tmp_db, mock_openai_client):
"""Create a ChatSession with defaults for truncation testing."""
return ChatSession(
client=mock_openai_client,
model="test-model",
ui=MagicMock(),
instructions=None,
temperature=0.5,
tool_timeout=10,
context_window=10_000,
max_tokens=1_000,
)
# ---------------------------------------------------------------------------
# _truncate_output
# ---------------------------------------------------------------------------
class TestTruncateOutput:
def test_no_truncation_when_under_limit(self, session):
result = session._truncate_output("short text")
assert result == "short text"
def test_truncates_to_tool_truncation_limit(self, session):
session.tool_truncation = 100
big = "x" * 500
result = session._truncate_output(big)
assert len(result) <= 200 # head + tail + marker
assert "chars truncated" in result
def test_budget_aware_truncation(self, session):
session.tool_truncation = 100_000
session._chars_per_token = 4.0
# Budget of 50 tokens = 200 chars
big = "x" * 1000
result = session._truncate_output(big, remaining_budget_tokens=50)
assert len(result) <= 400 # head + tail + marker
assert "chars truncated" in result
def test_budget_takes_precedence_when_smaller(self, session):
session.tool_truncation = 10_000
session._chars_per_token = 4.0
# Budget of 25 tokens = 100 chars, smaller than tool_truncation
big = "x" * 500
result = session._truncate_output(big, remaining_budget_tokens=25)
assert "chars truncated" in result
def test_zero_budget_returns_placeholder(self, session):
big = "x" * 1000
result = session._truncate_output(big, remaining_budget_tokens=0)
assert "exceeded context budget" in result
assert len(result) < 100
def test_negative_budget_returns_placeholder(self, session):
big = "x" * 1000
result = session._truncate_output(big, remaining_budget_tokens=-10)
assert "exceeded context budget" in result
def test_none_budget_uses_fixed_limit(self, session):
session.tool_truncation = 100
big = "x" * 500
result = session._truncate_output(big, remaining_budget_tokens=None)
assert "100 char limit" in result
# ---------------------------------------------------------------------------
# _remaining_token_budget
# ---------------------------------------------------------------------------
class TestRemainingTokenBudget:
def test_empty_session(self, session):
session._tools = [] # isolate the budget formula from the tool-def estimate
session._system_tokens = 500
session._msg_tokens = []
budget = session._remaining_token_budget()
# 10000 - 500 - 0 - 1000 - 500 (5%) = 8000
assert budget == 8000
def test_partially_full(self, session):
session._tools = [] # isolate the budget formula from the tool-def estimate
session._system_tokens = 500
session._msg_tokens = [2000, 3000]
budget = session._remaining_token_budget()
# 10000 - 500 - 5000 - 1000 - 500 = 3000
assert budget == 3000
def test_overfull_returns_zero(self, session):
session._system_tokens = 500
session._msg_tokens = [9000]
assert session._remaining_token_budget() == 0
def test_exactly_full_returns_zero(self, session):
session._system_tokens = 500
session._msg_tokens = [8000]
assert session._remaining_token_budget() == 0
def test_max_tokens_equals_context_window(self, tmp_db, mock_openai_client):
"""Regression: max_tokens >= context_window must not zero the budget."""
s = ChatSession(
client=mock_openai_client,
model="test-model",
ui=MagicMock(),
instructions=None,
temperature=0.5,
tool_timeout=10,
context_window=32_768,
max_tokens=32_768,
)
s._tools = [] # isolate the budget formula from the tool-def estimate
s._system_tokens = 500
s._msg_tokens = [1000]
budget = s._remaining_token_budget()
# response_reserve = min(32768, 32768//4) = 8192
# safety = 32768 * 0.05 = 1638
# budget = 32768 - 500 - 1000 - 8192 - 1638 = 21438
assert budget > 20_000
# Tool output should NOT be collapsed to a placeholder
big = "x" * 5000
result = s._truncate_output(big, remaining_budget_tokens=budget)
assert result == big # 5000 chars fits easily in 21K+ token budget
# ---------------------------------------------------------------------------
# Context overflow recovery
# ---------------------------------------------------------------------------
class TestContextOverflowRecovery:
"""Test that context-length errors trigger compact-and-retry."""
def test_openai_context_length_error_triggers_compact(self, session):
session.messages = turns_from_dicts([{"role": "user", "content": "hi"}])
session._msg_tokens = [1]
call_count = 0
def mock_create_stream(msgs):
nonlocal call_count
call_count += 1
if call_count == 1:
raise Exception("maximum context length exceeded")
return iter([])
compact_mock = MagicMock()
with (
patch.object(session, "_create_stream_with_retry", side_effect=mock_create_stream),
patch.object(session, "_compact_messages", compact_mock),
patch.object(
session, "_stream_response", return_value={"role": "assistant", "content": "ok"}
),
patch.object(session, "_full_messages", return_value=[]),
patch.object(session, "_update_token_table"),
patch.object(session, "_print_status_line"),
patch.object(session, "_emit_state"),
patch("turnstone.core.session.save_message"),
):
session.send("hello")
# my_generation must be the send's own generation — a stale send that
# hits overflow must not compact-and-swap a newer generation's history.
compact_mock.assert_called_once_with(auto=True, my_generation=session._generation)
assert call_count == 2
def test_anthropic_prompt_too_long_triggers_compact(self, session):
session.messages = turns_from_dicts([{"role": "user", "content": "hi"}])
session._msg_tokens = [1]
call_count = 0
def mock_create_stream(msgs):
nonlocal call_count
call_count += 1
if call_count == 1:
raise Exception("prompt is too long: 250000 tokens > 200000 maximum")
return iter([])
compact_mock = MagicMock()
with (
patch.object(session, "_create_stream_with_retry", side_effect=mock_create_stream),
patch.object(session, "_compact_messages", compact_mock),
patch.object(
session, "_stream_response", return_value={"role": "assistant", "content": "ok"}
),
patch.object(session, "_full_messages", return_value=[]),
patch.object(session, "_update_token_table"),
patch.object(session, "_print_status_line"),
patch.object(session, "_emit_state"),
patch("turnstone.core.session.save_message"),
):
session.send("hello")
compact_mock.assert_called_once_with(auto=True, my_generation=session._generation)
def test_non_context_error_propagates(self, session):
session.messages = turns_from_dicts([{"role": "user", "content": "hi"}])
session._msg_tokens = [1]
with (
patch.object(
session,
"_create_stream_with_retry",
side_effect=Exception("authentication failed"),
),
patch.object(session, "_full_messages", return_value=[]),
patch.object(session, "_emit_state"),
patch("turnstone.core.session.save_message"),
pytest.raises(Exception, match="authentication failed"),
):
session.send("hello")
def test_compact_failure_raises_original_error(self, session):
session.messages = turns_from_dicts([{"role": "user", "content": "hi"}])
session._msg_tokens = [1]
with (
patch.object(
session,
"_create_stream_with_retry",
side_effect=Exception("maximum context length exceeded"),
),
patch.object(session, "_compact_messages", side_effect=RuntimeError("compact failed")),
patch.object(session, "_full_messages", return_value=[]),
patch.object(session, "_emit_state"),
patch("turnstone.core.session.save_message"),
pytest.raises(Exception, match="maximum context length exceeded"),
):
session.send("hello")