Files
hermes-agent/tests/agent/test_tool_guardrails.py

481 lines
20 KiB
Python

"""Pure tool-call guardrail primitive tests."""
import json
from agent.tool_guardrails import (
ToolCallGuardrailConfig,
ToolCallGuardrailController,
ToolCallSignature,
canonical_tool_args,
classify_tool_failure,
)
def test_tool_call_signature_hashes_canonical_nested_unicode_args_without_exposing_raw_args():
args_a = {
"z": [{"β": "☤", "a": 1}],
"a": {"y": 2, "x": "secret-token-value"},
}
args_b = {
"a": {"x": "secret-token-value", "y": 2},
"z": [{"a": 1, "β": "☤"}],
}
assert canonical_tool_args(args_a) == canonical_tool_args(args_b)
sig_a = ToolCallSignature.from_call("web_search", args_a)
sig_b = ToolCallSignature.from_call("web_search", args_b)
assert sig_a == sig_b
assert len(sig_a.args_hash) == 64
metadata = sig_a.to_metadata()
assert metadata == {"tool_name": "web_search", "args_hash": sig_a.args_hash}
assert "secret-token-value" not in json.dumps(metadata)
assert "☤" not in json.dumps(metadata)
def test_config_parses_nested_warn_and_hard_stop_thresholds():
cfg = ToolCallGuardrailConfig.from_mapping(
{
"warnings_enabled": False,
"hard_stop_enabled": True,
"warn_after": {
"exact_failure": 3,
"same_tool_failure": 4,
"idempotent_no_progress": 5,
},
"hard_stop_after": {
"exact_failure": 6,
"same_tool_failure": 7,
"idempotent_no_progress": 8,
},
}
)
assert cfg.warnings_enabled is False
assert cfg.hard_stop_enabled is True
assert cfg.exact_failure_warn_after == 3
assert cfg.same_tool_failure_warn_after == 4
assert cfg.no_progress_warn_after == 5
assert cfg.exact_failure_block_after == 6
assert cfg.same_tool_failure_halt_after == 7
assert cfg.no_progress_block_after == 8
def test_gateway_platform_defaults_to_hard_stop_without_changing_interactive_defaults():
interactive_configs = [
ToolCallGuardrailConfig.from_mapping({}, platform=platform)
for platform in ("cli", "tui", "desktop", "acp")
]
telegram_cfg = ToolCallGuardrailConfig.from_mapping({}, platform="telegram")
cron_cfg = ToolCallGuardrailConfig.from_mapping({}, platform="cron")
assert all(cfg.hard_stop_enabled is False for cfg in interactive_configs)
assert telegram_cfg.hard_stop_enabled is True
assert cron_cfg.hard_stop_enabled is True
def test_non_interactive_hard_stop_can_be_disabled_explicitly():
cfg = ToolCallGuardrailConfig.from_mapping(
{"non_interactive_hard_stop_enabled": False},
platform="telegram",
)
assert cfg.hard_stop_enabled is False
assert cfg.non_interactive_hard_stop_enabled is False
def test_default_repeated_identical_failed_call_warns_without_blocking():
controller = ToolCallGuardrailController()
args = {"query": "same"}
decisions = []
for _ in range(5):
assert controller.before_call("web_search", args).action == "allow"
decisions.append(
controller.after_call("web_search", args, '{"error":"boom"}', failed=True)
)
assert decisions[0].action == "allow"
assert [d.action for d in decisions[1:]] == ["warn", "warn", "warn", "warn"]
assert {d.code for d in decisions[1:]} == {"repeated_exact_failure_warning"}
assert controller.before_call("web_search", args).action == "allow"
assert controller.halt_decision is None
def test_hard_stop_enabled_blocks_repeated_exact_failure_before_next_execution():
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(
hard_stop_enabled=True,
exact_failure_warn_after=2,
exact_failure_block_after=2,
same_tool_failure_halt_after=99,
)
)
args = {"query": "same"}
assert controller.before_call("web_search", args).action == "allow"
first = controller.after_call("web_search", args, '{"error":"boom"}', failed=True)
assert first.action == "allow"
assert controller.before_call("web_search", args).action == "allow"
second = controller.after_call("web_search", args, '{"error":"boom"}', failed=True)
assert second.action == "warn"
assert second.code == "repeated_exact_failure_warning"
blocked = controller.before_call("web_search", args)
assert blocked.action == "block"
assert blocked.code == "repeated_exact_failure_block"
assert blocked.count == 2
def test_skill_read_tools_are_idempotent_and_block_repeated_identical_success_output():
cases = [
(
"skill_view",
{"name": "gui-agent-ml-operations"},
'{"success":true,"name":"gui-agent-ml-operations","content":"same"}',
),
(
"skills_list",
{"category": "mlops"},
'{"success":true,"skills":[{"name":"gui-agent-ml-operations"}]}',
),
]
for tool_name, args, result in cases:
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(
hard_stop_enabled=True,
no_progress_warn_after=2,
no_progress_block_after=2,
)
)
assert controller.before_call(tool_name, args).action == "allow"
assert controller.after_call(tool_name, args, result, failed=False).action == "allow"
assert controller.before_call(tool_name, args).action == "allow"
warn = controller.after_call(tool_name, args, result, failed=False)
assert warn.action == "warn"
assert warn.code == "idempotent_no_progress_warning"
blocked = controller.before_call(tool_name, args)
assert blocked.action == "block"
assert blocked.code == "idempotent_no_progress_block"
def test_mutating_or_unknown_tools_are_not_blocked_for_repeated_identical_success_output_by_default():
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(no_progress_warn_after=2, no_progress_block_after=2)
)
for _ in range(3):
assert controller.before_call("write_file", {"path": "/tmp/x", "content": "x"}).action == "allow"
assert controller.after_call("write_file", {"path": "/tmp/x", "content": "x"}, "ok", failed=False).action == "allow"
assert controller.before_call("custom_tool", {"x": 1}).action == "allow"
assert controller.after_call("custom_tool", {"x": 1}, "ok", failed=False).action == "allow"
def test_identical_call_streak_halts_any_tool_when_hard_stop_enabled():
# #89069 / #100849 bundle: a model replaying the same SUCCESSFUL
# terminal/skill_view call with a byte-identical result is not covered by
# the idempotent_tools no-progress block. The consecutive-identical
# streak (observe_call) is tool-agnostic; under hard_stop it must halt.
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(hard_stop_enabled=True, no_progress_block_after=5)
)
args = {"command": "hermes config get memory.provider"}
for i in range(1, 5):
controller.after_call("terminal", args, "local\n", failed=False)
controller.observe_call("terminal", args, "local\n", failed=False)
assert controller.halt_decision is None, f"halted early at {i}"
controller.after_call("terminal", args, "local\n", failed=False)
controller.observe_call("terminal", args, "local\n", failed=False)
halt = controller.halt_decision
assert halt is not None and halt.should_halt
assert halt.code == "identical_call_streak_halt"
assert halt.tool_name == "terminal" and halt.count == 5
def test_identical_call_streak_never_halts_when_hard_stop_disabled_or_for_pollers():
soft = ToolCallGuardrailController(
ToolCallGuardrailConfig(hard_stop_enabled=False, no_progress_block_after=2)
)
for _ in range(6):
soft.observe_call("terminal", {"command": "ls"}, "a\nb\n", failed=False)
assert soft.halt_decision is None # notice-only in interactive sessions
hard = ToolCallGuardrailController(
ToolCallGuardrailConfig(hard_stop_enabled=True, no_progress_block_after=2)
)
for _ in range(6):
hard.observe_call("process_manage", {"action": "poll", "session_id": "p1"}, "running", failed=False)
assert hard.halt_decision is None # an unchanged poll is legitimate progress
# A changed result resets the streak.
for i in range(6):
hard.observe_call("terminal", {"command": "date"}, f"t{i}", failed=False)
assert hard.halt_decision is None
# ── Per-turn runaway-loop caps (Claude Code v2.1.212, Week 29) ──────────────
from agent.tool_guardrails import LoopCapConfig # noqa: E402
def test_loop_cap_zero_disables_and_junk_falls_back():
# 0 is a legitimate "unlimited" value; negatives / junk fall back to default.
assert LoopCapConfig.from_mapping({"max_web_searches": 0}).max_web_searches == 0
assert LoopCapConfig.from_mapping({"max_web_searches": -5}).max_web_searches == LoopCapConfig().max_web_searches
assert LoopCapConfig.from_mapping({"max_subagents": "nope"}).max_subagents == LoopCapConfig().max_subagents
def test_web_search_cap_blocks_after_limit_regardless_of_hard_stop():
# Loop caps fire even with hard_stop_enabled=False (the per-turn loop
# detector's flag). Each distinct query avoids the loop detector so we know
# the block came from the loop cap, not exact-failure repetition.
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(
hard_stop_enabled=False,
loop_caps=LoopCapConfig(max_web_searches=3),
)
)
for i in range(3):
assert controller.before_call("web_search", {"query": f"q{i}"}).action == "allow"
decision = controller.before_call("web_search", {"query": "q4"})
assert decision.action == "block"
assert decision.code == "loop_web_search_cap"
assert decision.should_halt is True
# ── Legitimate flows must survive hard stops (Teknium, Sep 2026) ────────────
# Hard stops default ON for unattended platforms. These pin the flows that
# must NEVER be cut off there: edit -> re-run loops, diagnostic sweeps of
# distinct red commands, and browser retry-after-action — while the pure
# replay (same call, nothing changed between attempts) is still stopped.
_HARD = lambda: ToolCallGuardrailController( # noqa: E731
ToolCallGuardrailConfig(hard_stop_enabled=True)
)
_PYTEST = {"command": "pytest tests/test_x.py -q"}
_RED = '{"output": "1 failed", "exit_code": 1}'
def _run_red(c, args=_PYTEST):
assert c.before_call("terminal", args).allows_execution
return c.after_call("terminal", args, _RED, failed=True)
def test_fix_retest_loop_is_never_hard_stopped():
c = _HARD()
for i in range(12):
d = _run_red(c)
assert not d.should_halt, f"halted on red run {i + 1}"
# the model edits between runs — a landed mutation is progress
c.after_call("patch", {"path": "x.py", "old_string": "a", "new_string": f"b{i}"},
'{"success": true, "diff": "..."}', failed=False)
assert c.halt_decision is None
assert c.before_call("terminal", _PYTEST).allows_execution
def test_pure_replay_with_no_intervening_change_is_still_blocked():
c = _HARD()
for _ in range(5):
_run_red(c)
d = c.before_call("terminal", _PYTEST)
assert d.action == "block" and d.code == "repeated_exact_failure_block"
def test_intervening_mutation_resets_the_replay_streak_only_once():
# 4 reds, one edit, then 4 reds with NO edit: the second run of 4 is a
# fresh streak, and the 5th unchanged retry after it is blocked.
c = _HARD()
for _ in range(4):
_run_red(c)
c.after_call("write_file", {"path": "x.py", "content": "y"}, '{"bytes_written": 1}', failed=False)
for _ in range(5):
assert c.before_call("terminal", _PYTEST).allows_execution
c.after_call("terminal", _PYTEST, _RED, failed=True)
assert c.before_call("terminal", _PYTEST).action == "block"
def test_distinct_failing_terminal_commands_warn_but_never_halt():
# A diagnostic sweep: grep with no matches, missing binaries, red builds.
c = _HARD()
for i in range(12):
args = {"command": f"grep -q needle{i} haystack.txt"}
d = c.after_call("terminal", args, _RED, failed=True)
assert not d.should_halt, f"same_tool halt on distinct command #{i + 1}"
assert c.halt_decision is None
# ...while a non-tolerant tool failing 8 distinct ways still halts.
c2 = _HARD()
last = None
for i in range(8):
last = c2.after_call("send_message", {"to": f"u{i}"}, '{"error": "no route"}', failed=True)
assert last.should_halt and last.code == "same_tool_failure_halt"
def test_browser_retry_after_action_is_not_a_replay():
c = _HARD()
nav = {"url": "https://example.test/app"}
for _ in range(8):
assert c.before_call("browser_navigate", nav).allows_execution
c.after_call("browser_navigate", nav, '{"error": "timeout"}', failed=True)
c.after_call("browser_click", {"selector": "#retry"}, '{"ok": true}', failed=False)
assert c.halt_decision is None
def test_supervised_task_platforms_keep_warning_only_default():
for platform in ("subagent", "api_server", "cli"):
cfg = ToolCallGuardrailConfig.from_mapping({}, platform=platform)
assert cfg.hard_stop_enabled is False, platform
for platform in ("telegram", "discord", "cron", "kanban"):
cfg = ToolCallGuardrailConfig.from_mapping({}, platform=platform)
assert cfg.hard_stop_enabled is True, platform
def test_harness_refusals_are_not_tool_failures_on_either_classifier(tmp_path):
"""Every loop refusal the file tools emit (read dedup block, consecutive-read block,
repeated-search block) carries `"error"` for the model's benefit -- exactly what the
substring tests key on. Neither `classify_tool_failure` nor the executor's live seam
`_detect_tool_failure` may count them, or the cheap refusal feeds the streak that
fires `repeated_exact_failure_block` over calls that never failed."""
from agent.display import _detect_tool_failure
from tools.file_tools import _dedup_stub_or_block, read_file_tool, search_tool
target = tmp_path / "responses.ts"
target.write_text("export const x = 1;\n" * 30, encoding="utf-8")
task = {"dedup_hits": {}}
for _ in range(3):
dedup_block = _dedup_stub_or_block(task, (str(target), 1, 999), str(target))
consecutive_block = [read_file_tool(str(target), offset=1, limit=5, task_id="t-read") for _ in range(4)][-1]
search_block = [search_tool("const x", path=str(tmp_path), task_id="t-search") for _ in range(4)][-1]
for refusal in (dedup_block, consecutive_block, search_block):
assert json.loads(refusal)["error"].startswith("BLOCKED"), refusal
assert classify_tool_failure("read_file", refusal) == (False, ""), refusal
assert _detect_tool_failure("read_file", refusal) == (False, ""), refusal
def test_a_real_tool_error_is_still_a_failure():
"""The exemption is keyed on the marker, not on the word: a body that
genuinely failed still counts, or the streak that stops a real loop is gone."""
from agent.display import _detect_tool_failure
real = '{"error": "ENOENT: no such file"}'
assert classify_tool_failure("read_file", real)[0] is True
assert _detect_tool_failure("read_file", real)[0] is True
# The marker is only honoured as the literal boolean, never as truthy prose.
assert classify_tool_failure("read_file", '{"error": "x", "guardrail_refusal": "yes"}')[0] is True
def test_identical_streak_ignores_volatile_execution_metadata():
# execute_code results carry per-call metadata (execution_count, duration_seconds) that
# changes on every run. Hashing it made each empty replay look "new", so a model re-ran
# the same empty probe 147 times without the identical-call halt ever firing.
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(hard_stop_enabled=True, no_progress_block_after=5)
)
args = {"code": "import subprocess\nprint(subprocess.run(['true']).returncode) if False else None"}
def result(n):
return json.dumps({
"status": "success", "output": "", "exit_code": 0, "tool_calls_made": 0,
"duration_seconds": 1.0 + n / 100,
"kernel": {"mode": "session", "reused": True, "execution_count": 100 + n, "state_reset": False},
"stdout_truncated": False, "stdout_bytes_captured": 0,
})
for i in range(4):
controller.observe_call("execute_code", args, result(i), failed=False)
assert controller.halt_decision is None, f"halted early at {i}"
controller.observe_call("execute_code", args, result(4), failed=False)
halt = controller.halt_decision
assert halt is not None, "volatile metadata defeated the identical-call streak"
assert halt.code == "identical_call_streak_halt"
def test_identical_streak_still_resets_when_real_output_changes():
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(hard_stop_enabled=True, no_progress_block_after=3)
)
args = {"code": "print(1)"}
for i in range(6):
out = json.dumps({"status": "success", "output": f"line {i}", "duration_seconds": 1.0,
"kernel": {"execution_count": i}})
controller.observe_call("execute_code", args, out, failed=False)
assert controller.halt_decision is None, "different real output must not count as a replay"
def test_other_tools_keep_duration_and_execution_count_as_real_output():
# Only execute_code's known metadata locations are volatile. For any other tool these keys
# can be the actual answer (e.g. a job-status tool reporting how long a job ran), so results
# that differ only there are different results and must not form an identical streak.
controller = ToolCallGuardrailController(
ToolCallGuardrailConfig(hard_stop_enabled=True, no_progress_block_after=3)
)
args = {"job": "build-42"}
for i in range(6):
out = json.dumps({"status": "done", "duration_seconds": 10 + i,
"stats": {"execution_count": 100 + i}})
controller.observe_call("mcp_ci_job_status", args, out, failed=False)
assert controller.halt_decision is None, "a real change in duration_seconds/execution_count was treated as a replay"
def test_execute_code_replay_streak_notice_fires_on_warn_only_desktop_config():
# #124072: on an interactive surface hard stops are off, so the appended notice is
# the only signal the model gets. 186 no-op print("...") cells whose results differed
# only in kernel.execution_count / duration_seconds produced zero notices.
controller = ToolCallGuardrailController(ToolCallGuardrailConfig.from_mapping({}, platform="desktop"))
args = {"code": 'print("...")'}
def result(n):
return json.dumps({
"status": "success", "output": "...\n", "exit_code": 0, "tool_calls_made": 0,
"duration_seconds": 0.001 * n,
"kernel": {"mode": "session", "reused": True, "execution_count": n, "state_reset": False},
"stdout_truncated": False, "stdout_bytes_captured": 4, "stdout_bytes_total": 4,
"stdout_bytes_omitted": 0,
})
notices = [
controller.observe_call("execute_code", args, result(i), tool_call_id=f"c{i}").notice
for i in range(1, 7)
]
assert notices[:2] == [None, None]
assert all(n is not None and "consecutive identical call to execute_code" in n for n in notices[2:]), notices
assert controller.halt_decision is None, "warn-only surfaces must not halt"