Ln 514 Test Log Analyzer

> **Paths:** File paths (`references/`, `../ln-*`) are relative to this skill directory.

# Test Log Analyzer

**Type:** L3 Worker
**Category:** 5XX Quality

Two-layer analysis of application logs. Node.js script handles collection and quantitative analysis; AI handles classification, quality assessment, and fix recommendations.

## Inputs

No required inputs. Runs in current project directory, auto-detects log sources.

Optional `args` — caller instructions (natural language): time window, expected errors, test context. Example: `"review logs for last 30min, auth 401 errors expected from negative tests"`.

## Purpose & Scope
- Analyze application logs (after test runs, during development, or on demand)
- Classify errors into 4 categories: Real Bug, Test Artifact, Expected Behavior, Operational Warning
- Assess log quality: noisiness, completeness, level correctness, format, structured logging
- Map stack traces to source files; provide fix recommendations
- Report findings for quality verdict (only Real Bugs block)
- **No status changes or task creation** — report only

## When to Use
- Analyze application logs in any project (default: last 1h)
- After test runs to classify errors and assess log quality
- Can be invoked with context instructions: `Skill(skill: "ln-514-test-log-analyzer", args: "review last 30min, 401 errors expected")`

## Workflow

### Phase 0: Parse Instructions

If `args` provided — extract: time window (default: 1h), expected errors list, test context.
If no `args` — use defaults (last 1h, no expected errors).

### Phase 1: Log Source Detection and Script Execution

Read target project files if they exist: `docs/project/infrastructure.md`, `docs/project/runbook.md`

1) Check if `scripts/analyze_test_logs.mjs` exists in target project. If missing, copy from `references/scripts/analyze_test_logs.mjs`.
2) Detect log source mode (auto-detection priority: docker → file → loki):

| Mode | Detection | Source |
|------|-----------|--------|
| `docker` | `docker compose ps` returns running containers | `docker compose logs --since {window}` |
| `file` | `.log` files exist, or `tests/manual/results/` has output | File paths from infrastructure.md or `*.log` glob |
| `loki` | `LOKI_URL` env var or `environment_state.json` observability section | Loki HTTP query_range API |

3) Run script: `node scripts/analyze_test_logs.mjs --mode {detected} [options]`
4) If no log sources found → return `NO_LOG_SOURCES` status, skip to Phase 5.