File size: 23,730 Bytes
3fbbaab 0bcc198 3fbbaab 0bcc198 3fbbaab 0bcc198 3fbbaab 7609903 0bcc198 7609903 0bcc198 7609903 3fbbaab | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 | """
tests/test_context_monitor.py -- pytest suite for context_monitor module.
Covers:
- extract_signals (keyword match, extension match, Bash tool signals, empty input)
- load_manifest_skills (happy, missing file, bad json)
- append_intent_log (creates file, appends)
- count_recent_unmatched (matched vs unmatched)
- write_pending_skills (creates file, content)
- load_recent_unmatched_count (happy path, missing file, skips bad lines)
- _parse_stdin_payload (valid JSON, empty stdin, non-dict, bad JSON)
- main() (--tool/--input flags, --from-stdin flag, no signals exit-0)
"""
import io
import json
import sys
from datetime import datetime, timezone
from pathlib import Path
import pytest
sys.path.insert(0, str(Path(__file__).parents[1]))
from ctx.adapters.claude_code.hooks import context_monitor as _cm
from ctx.adapters.claude_code.hooks.context_monitor import (
_parse_stdin_payload,
append_intent_log,
count_recent_unmatched,
extract_signals,
load_manifest_skills,
load_recent_unmatched_count,
write_pending_skills,
)
TODAY = datetime.now(timezone.utc).strftime("%Y-%m-%d")
# ---------------------------------------------------------------------------
# extract_signals
# ---------------------------------------------------------------------------
class TestExtractSignals:
def test_keyword_match_react(self):
signals = extract_signals("Read", {"file_path": "src/App.tsx"})
assert "react" in signals
def test_keyword_match_docker(self):
signals = extract_signals("Read", {"file_path": "Dockerfile"})
assert "docker" in signals
def test_extension_tsx_triggers_react(self):
signals = extract_signals("Read", {"file_path": "component.tsx"})
assert "react" in signals
def test_extension_tf_triggers_terraform(self):
signals = extract_signals("Write", {"file_path": "main.tf"})
assert "terraform" in signals
def test_bash_pip_install_triggers_python(self):
signals = extract_signals("Bash", {"command": "pip install fastapi"})
assert "python" in signals
def test_bash_npm_install_triggers_javascript(self):
signals = extract_signals("Bash", {"command": "npm install react"})
assert "javascript" in signals
def test_empty_input_returns_empty(self):
signals = extract_signals("Read", {})
assert signals == []
def test_no_match_returns_empty(self):
signals = extract_signals("Read", {"file_path": "README.md"})
assert signals == []
def test_multiple_signals_deduped(self):
signals = extract_signals("Read", {"content": "react jsx tsx"})
# react should appear only once despite 3 matching keywords
assert signals.count("react") == 1
def test_signals_sorted(self):
signals = extract_signals("Bash", {"command": "docker-compose up"})
assert signals == sorted(signals)
def test_anthropic_keyword_maps_to_sdk(self):
signals = extract_signals("Read", {"content": "from anthropic import Anthropic"})
assert "anthropic-sdk" in signals
def test_kubernetes_keyword_match(self):
signals = extract_signals("Bash", {"command": "kubectl apply -f deployment.yaml"})
assert "kubernetes" in signals
def test_case_insensitive_match(self):
signals = extract_signals("Read", {"content": "FASTAPI app = FastAPI()"})
assert "fastapi" in signals
# ---------------------------------------------------------------------------
# load_manifest_skills
# ---------------------------------------------------------------------------
class TestLoadManifestSkills:
def test_happy_path(self, tmp_path, monkeypatch):
manifest = {"load": [{"skill": "react"}, {"skill": "docker"}]}
mpath = tmp_path / "manifest.json"
mpath.write_text(json.dumps(manifest))
monkeypatch.setattr(_cm, "MANIFEST_PATH", mpath)
result = load_manifest_skills()
assert result == {"react", "docker"}
def test_missing_file_returns_empty_set(self, tmp_path, monkeypatch):
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "no-such.json")
assert load_manifest_skills() == set()
def test_bad_json_returns_empty_set(self, tmp_path, monkeypatch):
mpath = tmp_path / "manifest.json"
mpath.write_text("not-json")
monkeypatch.setattr(_cm, "MANIFEST_PATH", mpath)
assert load_manifest_skills() == set()
def test_empty_load_list(self, tmp_path, monkeypatch):
mpath = tmp_path / "manifest.json"
mpath.write_text(json.dumps({"load": []}))
monkeypatch.setattr(_cm, "MANIFEST_PATH", mpath)
assert load_manifest_skills() == set()
# ---------------------------------------------------------------------------
# append_intent_log
# ---------------------------------------------------------------------------
class TestAppendIntentLog:
def test_creates_file_and_appends(self, tmp_path, monkeypatch):
log = tmp_path / "intent.jsonl"
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
monkeypatch.setattr(_cm, "INTENT_LOG", log)
entry = {"date": TODAY, "signals": ["react"]}
append_intent_log(entry)
lines = [line for line in log.read_text().strip().split("\n") if line]
assert len(lines) == 1
assert json.loads(lines[0])["signals"] == ["react"]
def test_appends_multiple_entries(self, tmp_path, monkeypatch):
log = tmp_path / "intent.jsonl"
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
monkeypatch.setattr(_cm, "INTENT_LOG", log)
append_intent_log({"date": TODAY, "signals": ["react"]})
append_intent_log({"date": TODAY, "signals": ["docker"]})
lines = [line for line in log.read_text().strip().split("\n") if line]
assert len(lines) == 2
# ---------------------------------------------------------------------------
# count_recent_unmatched
# ---------------------------------------------------------------------------
class TestCountRecentUnmatched:
def test_all_matched(self):
unmatched = count_recent_unmatched(["react", "docker"], {"react", "docker"})
assert unmatched == []
def test_none_matched(self):
unmatched = count_recent_unmatched(["react", "docker"], set())
assert set(unmatched) == {"react", "docker"}
def test_partial_match(self):
unmatched = count_recent_unmatched(["react", "docker"], {"react"})
assert unmatched == ["docker"]
def test_empty_signals(self):
assert count_recent_unmatched([], {"react"}) == []
# ---------------------------------------------------------------------------
# write_pending_skills
# ---------------------------------------------------------------------------
class TestWritePendingSkills:
def test_writes_pending_skills_file(self, tmp_path, monkeypatch):
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(_cm, "graph_suggest", lambda unmatched: [])
write_pending_skills(["react", "docker"])
pending = json.loads((tmp_path / "pending.json").read_text())
assert pending["unmatched_signals"] == ["react", "docker"]
assert "suggestion" in pending
def test_suggestion_mentions_signals(self, tmp_path, monkeypatch):
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(_cm, "graph_suggest", lambda unmatched: [])
write_pending_skills(["fastapi"])
pending = json.loads((tmp_path / "pending.json").read_text())
assert "fastapi" in pending["suggestion"]
def test_empty_unmatched(self, tmp_path, monkeypatch):
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(_cm, "graph_suggest", lambda unmatched: [])
write_pending_skills([])
pending = json.loads((tmp_path / "pending.json").read_text())
assert pending["unmatched_signals"] == []
def test_graph_suggestions_list_present(self, tmp_path, monkeypatch):
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(
_cm,
"graph_suggest",
lambda unmatched: [{"name": "fastapi-pro", "type": "skill"}],
)
write_pending_skills(["unknown-signal"])
pending = json.loads((tmp_path / "pending.json").read_text())
assert pending["graph_suggestions"] == [{"name": "fastapi-pro", "type": "skill"}]
def test_graph_suggest_filters_to_execution_bundle_types(self, tmp_path, monkeypatch):
graph_path = tmp_path / "skill-wiki" / "graphify-out" / "graph.json"
graph_path.parent.mkdir(parents=True)
graph_path.write_text("{}", encoding="utf-8")
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
calls = {}
class FakeGraph:
def number_of_nodes(self):
return 1
fake_graph_module = type(
"FakeGraphModule",
(),
{"load_graph": staticmethod(lambda _path=None: FakeGraph())},
)
def fake_recommend_by_tags(graph, tags, **kwargs):
calls["entity_types"] = kwargs.get("entity_types")
return [{"name": "fastapi-pro", "type": "skill"}]
fake_recommend_module = type(
"FakeRecommendModule",
(),
{"recommend_by_tags": staticmethod(fake_recommend_by_tags)},
)
monkeypatch.setitem(sys.modules, "ctx.core.graph.resolve_graph", fake_graph_module)
monkeypatch.setitem(
sys.modules,
"ctx.core.resolve.recommendations",
fake_recommend_module,
)
assert _cm.graph_suggest(["fastapi"]) == [{"name": "fastapi-pro", "type": "skill"}]
assert calls["entity_types"] == ("skill", "agent", "mcp-server")
# ---------------------------------------------------------------------------
# load_recent_unmatched_count
# ---------------------------------------------------------------------------
class TestLoadRecentUnmatchedCount:
def _write_log(self, path: Path, entries: list[dict]) -> None:
path.write_text("\n".join(json.dumps(e) for e in entries) + "\n")
def test_happy_path_counts_distinct(self, tmp_path, monkeypatch):
log = tmp_path / "intent.jsonl"
self._write_log(log, [
{"date": TODAY, "unmatched": ["react", "docker"]},
{"date": TODAY, "unmatched": ["react"]}, # react already counted
])
monkeypatch.setattr(_cm, "INTENT_LOG", log)
count = load_recent_unmatched_count()
assert count == 2 # react + docker distinct
def test_missing_file_returns_0(self, tmp_path, monkeypatch):
monkeypatch.setattr(_cm, "INTENT_LOG", tmp_path / "nope.jsonl")
assert load_recent_unmatched_count() == 0
def test_skips_bad_lines(self, tmp_path, monkeypatch):
log = tmp_path / "intent.jsonl"
log.write_text(f'not-json\n{json.dumps({"date": TODAY, "unmatched": ["react"]})}\n')
monkeypatch.setattr(_cm, "INTENT_LOG", log)
assert load_recent_unmatched_count() == 1
def test_other_dates_not_counted(self, tmp_path, monkeypatch):
log = tmp_path / "intent.jsonl"
self._write_log(log, [{"date": "2000-01-01", "unmatched": ["react"]}])
monkeypatch.setattr(_cm, "INTENT_LOG", log)
assert load_recent_unmatched_count() == 0
# ---------------------------------------------------------------------------
# _parse_stdin_payload
# ---------------------------------------------------------------------------
class TestParseStdinPayload:
def test_valid_payload(self, monkeypatch):
payload = json.dumps({"tool_name": "Read", "tool_input": {"file_path": "foo.py"}})
monkeypatch.setattr(sys, "stdin", io.StringIO(payload))
tool_name, tool_input = _parse_stdin_payload()
assert tool_name == "Read"
assert tool_input == {"file_path": "foo.py"}
def test_empty_stdin(self, monkeypatch):
monkeypatch.setattr(sys, "stdin", io.StringIO(""))
tool_name, tool_input = _parse_stdin_payload()
assert tool_name == "unknown"
assert tool_input == {}
def test_non_dict_json(self, monkeypatch):
monkeypatch.setattr(sys, "stdin", io.StringIO(json.dumps([1, 2, 3])))
tool_name, tool_input = _parse_stdin_payload()
assert tool_name == "unknown"
def test_bad_json(self, monkeypatch):
monkeypatch.setattr(sys, "stdin", io.StringIO("not-json"))
tool_name, tool_input = _parse_stdin_payload()
assert tool_name == "unknown"
assert tool_input == {}
def test_missing_tool_input_defaults_to_empty(self, monkeypatch):
payload = json.dumps({"tool_name": "Bash"})
monkeypatch.setattr(sys, "stdin", io.StringIO(payload))
_, tool_input = _parse_stdin_payload()
assert tool_input == {}
def test_non_dict_tool_input_defaults_to_empty(self, monkeypatch):
payload = json.dumps({"tool_name": "Bash", "tool_input": "not-a-dict"})
monkeypatch.setattr(sys, "stdin", io.StringIO(payload))
_, tool_input = _parse_stdin_payload()
assert tool_input == {}
# ---------------------------------------------------------------------------
# main()
# ---------------------------------------------------------------------------
class TestMain:
def test_no_signals_exits_0(self, tmp_path, monkeypatch):
"""When tool input produces no signals, main exits 0."""
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
monkeypatch.setattr(_cm, "INTENT_LOG", tmp_path / "intent.jsonl")
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "manifest.json")
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(sys, "argv", ["context_monitor.py", "--tool", "Read", "--input", "{}"])
with pytest.raises(SystemExit) as exc:
_cm.main()
assert exc.value.code == 0
def test_signals_appended_to_log(self, tmp_path, monkeypatch):
"""Signals from --input are written to the intent log."""
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
log = tmp_path / "intent.jsonl"
monkeypatch.setattr(_cm, "INTENT_LOG", log)
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "manifest.json")
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(_cm, "_THRESHOLD", 999) # prevent pending write
tool_input = json.dumps({"file_path": "Dockerfile"})
monkeypatch.setattr(sys, "argv", ["context_monitor.py", "--tool", "Read", "--input", tool_input])
_cm.main()
lines = [line for line in log.read_text().strip().split("\n") if line]
assert len(lines) == 1
entry = json.loads(lines[0])
assert "docker" in entry["signals"]
def test_from_stdin_flag(self, tmp_path, monkeypatch):
"""--from-stdin reads tool payload from stdin."""
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
log = tmp_path / "intent.jsonl"
monkeypatch.setattr(_cm, "INTENT_LOG", log)
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "manifest.json")
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(_cm, "_THRESHOLD", 999)
payload = json.dumps({"tool_name": "Read", "tool_input": {"file_path": "Dockerfile"}})
monkeypatch.setattr(sys, "stdin", io.StringIO(payload))
monkeypatch.setattr(sys, "argv", ["context_monitor.py", "--from-stdin"])
_cm.main()
lines = [line for line in log.read_text().strip().split("\n") if line]
assert len(lines) == 1
entry = json.loads(lines[0])
assert "docker" in entry["signals"]
def test_bad_json_input_falls_back_to_raw(self, tmp_path, monkeypatch):
"""Malformed --input falls back to {'raw': value} and may produce no signals."""
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
log = tmp_path / "intent.jsonl"
monkeypatch.setattr(_cm, "INTENT_LOG", log)
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "manifest.json")
monkeypatch.setattr(_cm, "PENDING_SKILLS", tmp_path / "pending.json")
monkeypatch.setattr(sys, "argv", ["context_monitor.py", "--tool", "Read", "--input", "not-json"])
# Should not crash
try:
_cm.main()
except SystemExit as e:
assert e.code == 0 # exits 0 when no signals
def test_threshold_triggers_pending_write(self, tmp_path, monkeypatch):
"""When unmatched count >= threshold, pending-skills.json is written."""
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
log = tmp_path / "intent.jsonl"
pending = tmp_path / "pending.json"
monkeypatch.setattr(_cm, "INTENT_LOG", log)
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "manifest.json")
monkeypatch.setattr(_cm, "PENDING_SKILLS", pending)
monkeypatch.setattr(_cm, "_THRESHOLD", 1) # trigger on 1 unmatched
tool_input = json.dumps({"file_path": "Dockerfile"})
monkeypatch.setattr(sys, "argv", ["context_monitor.py", "--tool", "Read", "--input", tool_input])
_cm.main()
assert pending.exists()
# ---------------------------------------------------------------------------
# Cumulative-threshold regression (code-reviewer finding BLOCKER)
# ---------------------------------------------------------------------------
#
# Prior impl used ``len(unmatched) >= THRESHOLD`` where ``unmatched`` is the
# per-invocation list. A single tool call almost never surfaces 3 unmatched
# signals alone, so the default threshold=3 meant pending-skills.json was
# essentially never written — silently killing the suggestion arm of the
# alive loop. The fix walks the intent log and checks the cumulative
# (per-day, across all invocations) unmatched count against the threshold.
class TestCumulativeThreshold:
"""The threshold must fire on cumulative unmatched across today's log,
not just on a single invocation's count.
"""
def _setup_paths(self, tmp_path, monkeypatch):
log = tmp_path / "intent.jsonl"
pending = tmp_path / "pending.json"
monkeypatch.setattr(_cm, "CLAUDE_DIR", tmp_path)
monkeypatch.setattr(_cm, "INTENT_LOG", log)
monkeypatch.setattr(_cm, "MANIFEST_PATH", tmp_path / "manifest.json")
monkeypatch.setattr(_cm, "PENDING_SKILLS", pending)
return log, pending
def _run_main(self, monkeypatch, tool_name: str, tool_input: dict):
monkeypatch.setattr(
sys, "argv",
["context_monitor.py", "--tool", tool_name, "--input", json.dumps(tool_input)],
)
_cm.main()
def test_fires_on_cumulative_across_three_invocations(
self, tmp_path, monkeypatch,
):
"""Three invocations each surfacing ONE unmatched signal should
trigger pending-skills write when THRESHOLD=3.
This is the case the old len(unmatched)>=THRESHOLD check missed.
The user types a react file, then opens a Dockerfile, then edits
terraform — three separate tool calls, three different unmatched
signals, cumulatively at threshold.
"""
_, pending = self._setup_paths(tmp_path, monkeypatch)
monkeypatch.setattr(_cm, "_THRESHOLD", 3)
# Three invocations, one unique unmatched signal each.
self._run_main(monkeypatch, "Read", {"file_path": "App.tsx"}) # react
assert not pending.exists(), "fired after 1 cumulative unmatched"
self._run_main(monkeypatch, "Read", {"file_path": "Dockerfile"}) # docker
assert not pending.exists(), "fired after 2 cumulative unmatched"
self._run_main(monkeypatch, "Read", {"file_path": "main.tf"}) # terraform
assert pending.exists(), (
"did NOT fire after 3 cumulative unmatched — "
"the per-invocation threshold bug regressed"
)
def test_does_not_fire_below_cumulative_threshold(
self, tmp_path, monkeypatch,
):
"""Below-threshold cumulative count must NOT trigger.
Otherwise every first-keystroke would spam pending-skills.json.
"""
_, pending = self._setup_paths(tmp_path, monkeypatch)
monkeypatch.setattr(_cm, "_THRESHOLD", 3)
self._run_main(monkeypatch, "Read", {"file_path": "App.tsx"})
self._run_main(monkeypatch, "Read", {"file_path": "Dockerfile"})
# Only 2 unique signals accumulated; THRESHOLD=3 => no write.
assert not pending.exists()
def test_fires_when_single_invocation_surfaces_multiple(
self, tmp_path, monkeypatch,
):
"""Backward-compat: a single invocation carrying threshold-worth of
new signals on its own still fires (the old happy path)."""
_, pending = self._setup_paths(tmp_path, monkeypatch)
monkeypatch.setattr(_cm, "_THRESHOLD", 2)
# A Bash pip install surfaces multiple signals in one invocation.
self._run_main(
monkeypatch, "Bash",
{"command": "pip install fastapi django"},
)
assert pending.exists()
def test_pending_contains_cumulative_union(
self, tmp_path, monkeypatch,
):
"""When the threshold fires, pending-skills.json lists ALL of today's
unmatched signals, not just the current invocation's."""
_, pending = self._setup_paths(tmp_path, monkeypatch)
monkeypatch.setattr(_cm, "_THRESHOLD", 2)
self._run_main(monkeypatch, "Read", {"file_path": "App.tsx"})
self._run_main(monkeypatch, "Read", {"file_path": "Dockerfile"})
assert pending.exists()
payload = json.loads(pending.read_text())
unmatched = set(payload.get("unmatched_signals", []))
# Both react (from App.tsx) and docker (from Dockerfile) must be
# present — a fix that only reports the current invocation's
# signals would miss react.
assert {"react", "docker"}.issubset(unmatched), (
f"pending does not include cumulative signals: {unmatched}"
)
def test_duplicate_signals_across_invocations_count_once(
self, tmp_path, monkeypatch,
):
"""Unique-set cumulative count — repeated signals don't inflate.
The same file edited twice should not double-count toward the
threshold; otherwise a tight edit-save-edit-save loop would
auto-trigger suggestions on a single concept.
"""
_, pending = self._setup_paths(tmp_path, monkeypatch)
monkeypatch.setattr(_cm, "_THRESHOLD", 2)
self._run_main(monkeypatch, "Read", {"file_path": "App.tsx"}) # react
self._run_main(monkeypatch, "Read", {"file_path": "index.tsx"}) # react (dup)
# Only 1 unique unmatched concept; THRESHOLD=2 => no write.
assert not pending.exists()
|