feat: scaffold cosma-log-analyzer with 5 deterministic rules + fake MCAP e2e test

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/test_e2e.py

@@ -0,0 +1,73 @@
+from __future__ import annotations
+
+import io
+import json
+from pathlib import Path
+
+from cosma_log_analyzer.bus import StdoutPublisher
+from cosma_log_analyzer.main import analyze_mcap, emit
+
+
+EXPECTED_RULES = {
+    "imu_outliers",
+    "watchdog_imu",
+    "usbl_snr_low",
+    "usbl_distance_spike",
+    "battery_low",
+}
+
+
+def test_analyze_fake_mcap_produces_all_rule_types(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    fired = {a.rule for a in anomalies}
+    assert EXPECTED_RULES <= fired, f"missing rules: {EXPECTED_RULES - fired}"
+
+
+def test_analyze_fake_mcap_subject_propagated(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    assert anomalies
+    assert all(a.subject == "AUV206" for a in anomalies)
+
+
+def test_watchdog_detects_the_gap(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    watchdog = [a for a in anomalies if a.rule == "watchdog_imu"]
+    # The fixture inserts exactly one 3s gap.
+    assert len(watchdog) == 1
+    assert watchdog[0].context["gap_s"] > 2.9
+
+
+def test_battery_low_fires_once(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    bat = [a for a in anomalies if a.rule == "battery_low"]
+    assert len(bat) == 1
+    assert bat[0].severity == "critical"
+    assert bat[0].value < 13.5
+
+
+def test_usbl_distance_spike_fires_once(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    spikes = [a for a in anomalies if a.rule == "usbl_distance_spike"]
+    assert len(spikes) == 1
+    assert spikes[0].context["delta_m"] > 50.0
+
+
+def test_usbl_snr_low_fires(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    snr = [a for a in anomalies if a.rule == "usbl_snr_low"]
+    assert len(snr) >= 1
+    assert all(a.value < 5.0 for a in snr)
+
+
+def test_stdout_publisher_emits_json_lines(fake_mcap: Path) -> None:
+    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
+    buf = io.StringIO()
+    publisher = StdoutPublisher(stream=buf)
+    n = emit(anomalies, publisher)
+    publisher.close()
+    lines = [ln for ln in buf.getvalue().splitlines() if ln]
+    assert n == len(lines) == len(anomalies)
+    for line in lines:
+        obj = json.loads(line)
+        assert obj["subject"] == "AUV206"
+        assert obj["rule"] in EXPECTED_RULES