LedgerLine/tests/test_no_observability.py

"""G10 -- no observability tooling is present yet.

This test module guards the Phase 0 "before" state. It is expected to be
DELETED at the start of Phase 2, not maintained -- once real instrumentation
is added, every assertion here becomes actively wrong on purpose.
"""
import json
import re
import subprocess
from datetime import datetime, timedelta, timezone

import httpx
import pytest

from harness.config import HTTP_SERVICES, REPO_ROOT, SERVICE_URLS

pytestmark = pytest.mark.guard

FORBIDDEN_IMPORTS = ("opentelemetry", "prometheus_client", "structlog", "sentry_sdk", "elasticapm")


def _python_files():
    files = []
    for name in ("services", "common"):
        base = REPO_ROOT / name
        if base.is_dir():
            files.extend(base.rglob("*.py"))
    return files


def test_application_code_exists():
    """G10 (vacuous-pass guard): this module must not pass vacuously against
    an empty repo -- there must be application code for the import check
    below to actually inspect."""
    files = _python_files()
    assert files, (
        "no .py files found under services/ or common/ -- either the app hasn't "
        "been implemented yet, or the guard tests below would pass vacuously"
    )


def test_no_file_imports_observability_libraries():
    """G10: no file under services/ or common/ imports an observability library."""
    offenders = []
    for path in _python_files():
        text = path.read_text(errors="ignore")
        for lib in FORBIDDEN_IMPORTS:
            if re.search(rf"^\s*(import|from)\s+{re.escape(lib)}\b", text, re.MULTILINE):
                offenders.append((str(path.relative_to(REPO_ROOT)), lib))
    assert not offenders, offenders


def test_dependency_files_do_not_list_observability_libraries():
    """G10: neither requirements*.txt (excluding requirements-test.txt) nor
    pyproject.toml lists an observability library."""
    candidates = [p for p in REPO_ROOT.glob("requirements*.txt") if p.name != "requirements-test.txt"]
    pyproject = REPO_ROOT / "pyproject.toml"
    if pyproject.is_file():
        candidates.append(pyproject)

    offenders = []
    for path in candidates:
        text = path.read_text(errors="ignore").lower()
        for lib in FORBIDDEN_IMPORTS:
            if lib in text:
                offenders.append((str(path.relative_to(REPO_ROOT)), lib))
    assert not offenders, offenders


@pytest.mark.parametrize("service", HTTP_SERVICES)
async def test_no_service_exposes_metrics_endpoint(service):
    """G10: no service exposes /metrics."""
    async with httpx.AsyncClient(timeout=5.0) as client:
        resp = await client.get(f"{SERVICE_URLS[service]}/metrics")
    assert resp.status_code == 404


async def test_gateway_logs_are_plain_text_not_json():
    """G10: docker compose logs gateway emits plain text, not JSON: sample 20
    lines and assert none parse as a JSON object."""
    async with httpx.AsyncClient(timeout=5.0) as client:
        for _ in range(3):
            await client.get(f"{SERVICE_URLS['gateway']}/healthz")

    since = (datetime.now(timezone.utc) - timedelta(minutes=10)).isoformat()
    result = subprocess.run(
        ["docker", "compose", "logs", "gateway", "--since", since, "--no-color", "--no-log-prefix", "--tail", "20"],
        cwd=REPO_ROOT, capture_output=True, text=True, timeout=15,
    )
    lines = [l for l in result.stdout.splitlines() if l.strip()][-20:]
    assert lines, "no recent gateway log lines found"

    json_lines = 0
    for line in lines:
        try:
            json.loads(line)
            json_lines += 1
        except (json.JSONDecodeError, ValueError):
            pass
    assert json_lines == 0, f"{json_lines}/{len(lines)} gateway log lines parsed as JSON"