test(render): этап 0 — golden-эталоны фидов как оракул эквивалентности (#27)

Первый этап эпика рефакторинга рендер-пайплайна (#34): снимает полные
snapshot'ы выходов generate_channel_rss (RSS XML) и generate_channel_html
(HTML) на записанном РЕАЛЬНОМ корпусе (4 канала: bladerunnerblues, embedoka,
meow_design, theyforcedme) и закрепляет тестом сравнения. Оракул для всех
последующих этапов: изменение байтов фида без ссылки на пункт реестра §3
спеки = регрессия. Никакой продакшн рендер-код не тронут — только тест-инфра.

- tests/golden_replay.py: реплей-загрузчик (распикливает recorded/*.cache|
  *.chatinfo, monkeypatch tg_cache.cached_get_chat_history/cached_get_chat —
  буквально прод-путь cache-hit) + генератор goldens + нормализаторы.
- tests/test_stage0_golden.py: оракул (11 тестов — RSS×4, HTML×4 + guards).
- tests/test_data/golden/: 8 замороженных snapshot'ов (~1.9 МБ).
- tests/conftest.py: пин TZ=UTC (naive-даты kurigram интерпретируются в
  локальной tz → без пина pubDate дрейфует между машинами).

Нормализации (симметрично golden+actual, минимальные, каждая с источником
недетерминизма): strip <lastBuildDate> (feedgen now()), strip <generator>
(страховка), сортировка <div class="message-flags"> (merged-флаги —
list(set(...)), hash-порядок; убирается коммитом этапа 2 по §3.8).

Детерминизм подтверждён 3 способами: двойной in-process захват, разные
PYTHONHASHSEED, регенерация в отдельном процессе — нормализованный вывод
байт-идентичен. Полный сюит 332 passed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/conftest.py

@@ -7,6 +7,7 @@ suite order-independent regardless of collection order or invocation directory.
 """
 import os
 import sys
+import time
 
 ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
 if ROOT not in sys.path:
@@ -15,3 +16,9 @@ if ROOT not in sys.path:
 import tests.mock_config as _mock_config
 
 sys.modules['config'] = _mock_config
+
+# Pin the runner timezone to UTC (stage-0 golden determinism, issue #27).
+# Naive kurigram dates are interpreted by datetime.timestamp() in the LOCAL tz, so
+# without this pin RSS <pubDate> values drift between machines (this sandbox is MSK).
+os.environ['TZ'] = 'UTC'
+time.tzset()

tests/golden_replay.py

@@ -0,0 +1,187 @@
+# flake8: noqa
+# pylint: disable=import-outside-toplevel, missing-function-docstring, line-too-long
+"""Stage-0 golden-baseline replay helpers (render-pipeline refactor epic, issue #27/#34).
+
+Replays the frozen recorded corpus (tests/test_data/recorded/) through the REAL
+cache-hit path and captures the full generate_channel_rss / generate_channel_html
+output as an equivalence oracle for every later refactor stage. NO production render
+code is touched here — only a test loader + determinism pins.
+
+The recorded corpus was written by the prod bridge cache (tg_cache._save_*_to_cache):
+  {channel}.cache    -> {'timestamp', 'limit', 'messages': List[Message]}
+  {channel}.chatinfo -> {'timestamp', 'data': {'id', 'title', 'username'}}
+`timestamp` / `limit` are ignored (no freshness check) — this is literally the prod
+cache-hit payload the renderer sees in production.
+
+Run `python -m tests.golden_replay` from the repo root to (re)generate the goldens.
+"""
+import os
+import re
+import time
+import pickle
+from types import SimpleNamespace
+
+TESTS_DIR = os.path.dirname(os.path.abspath(__file__))
+ROOT = os.path.dirname(TESTS_DIR)
+RECORDED_DIR = os.path.join(TESTS_DIR, "test_data", "recorded")
+GOLDEN_DIR = os.path.join(TESTS_DIR, "test_data", "golden")
+
+# Corpus channels frozen on `main` (spec "Этап 0"). exclude_flags / exclude_text
+# scenarios are intentionally NOT in golden: filters do not change the bytes of the
+# surviving posts; their membership/regex semantics are covered by dedicated unit tests.
+CORPUS_CHANNELS = ["bladerunnerblues", "embedoka", "meow_design", "theyforcedme"]
+
+# Recorded corpus is 100 messages/channel; the feed cap is 200. limit=100 exercises the
+# whole corpus (grouping only reduces the post count below the message count).
+GOLDEN_LIMIT = 100
+
+# Fixed media-URL signing key so a golden captured on any machine/checkout reproduces on
+# regeneration (a fresh checkout otherwise mints a new secrets.token_hex and every URL
+# digest changes). Used identically by the generator and the comparison test.
+GOLDEN_SIGNING_KEY = "stage0-golden-fixed-signing-key-0000000000000000"
+
+
+# --------------------------------------------------------------------------- #
+# Replay loader — the literal prod cache-hit path.
+# --------------------------------------------------------------------------- #
+def load_recorded(channel):
+    """Unpickle a recorded {channel}.cache / {channel}.chatinfo pair.
+
+    Returns (messages: List[Message], chatinfo_data: dict). timestamp/limit ignored."""
+    with open(os.path.join(RECORDED_DIR, f"{channel}.cache"), "rb") as f:
+        cache = pickle.load(f)
+    with open(os.path.join(RECORDED_DIR, f"{channel}.chatinfo"), "rb") as f:
+        chatinfo = pickle.load(f)
+    return cache["messages"], chatinfo["data"]
+
+
+def patch_tg_cache(monkeypatch, channel):
+    """Monkeypatch tg_cache.cached_get_chat_history / cached_get_chat to return the
+    recorded objects for `channel`. The feed functions lazy-import tg_cache, so patching
+    the module resolves late and works (mirrors test_stage4_eventloop.py)."""
+    messages, chatinfo = load_recorded(channel)
+
+    async def fake_get_chat_history(client, channel_id, limit=20):
+        return messages
+
+    async def fake_get_chat(client, channel_id):
+        # cached_get_chat returns SimpleNamespace(**data) with .id/.title/.username.
+        return SimpleNamespace(**chatinfo)
+
+    monkeypatch.setattr("tg_cache.cached_get_chat_history", fake_get_chat_history, raising=False)
+    monkeypatch.setattr("tg_cache.cached_get_chat", fake_get_chat, raising=False)
+
+
+def pin_environment(monkeypatch):
+    """Apply the spec's non-TZ determinism pins (TZ=UTC is pinned globally in conftest /
+    the __main__ bootstrap so both the test runner and the generator agree)."""
+    import post_parser
+    import rss_generator
+    from url_signer import KeyManager
+
+    # Pin the media-URL signing key (see GOLDEN_SIGNING_KEY).
+    monkeypatch.setattr(KeyManager, "signing_key", GOLDEN_SIGNING_KEY)
+
+    # time_based_merge=True so the meow_design time-cluster core is actually exercised.
+    # The flag is read from rss_generator.Config at call time; post_parser.Config is a
+    # sibling dict from the same get_settings() — pin both (cheap insurance vs. drift).
+    monkeypatch.setitem(rss_generator.Config, "time_based_merge", True)
+    monkeypatch.setitem(post_parser.Config, "time_based_merge", True)
+
+    # No media-id DB side effect outside tests/ (byte-neutral for the feed, but the write
+    # to ./data/media_file_ids.db is a forbidden side effect). upsert is imported INTO the
+    # post_parser namespace, so patch it there.
+    monkeypatch.setattr(post_parser, "upsert_media_file_ids_bulk_sync", lambda *a, **k: None)
+
+
+# --------------------------------------------------------------------------- #
+# Capture.
+# --------------------------------------------------------------------------- #
+def capture_rss(channel):
+    import asyncio
+    from rss_generator import generate_channel_rss
+    return asyncio.run(generate_channel_rss(channel, client=SimpleNamespace(), limit=GOLDEN_LIMIT))
+
+
+def capture_html(channel):
+    import asyncio
+    from rss_generator import generate_channel_html
+    return asyncio.run(generate_channel_html(channel, client=SimpleNamespace(), limit=GOLDEN_LIMIT))
+
+
+# --------------------------------------------------------------------------- #
+# Normalizations (applied SYMMETRICALLY to golden and actual before comparison).
+# Only the spec-sanctioned set — over-normalizing is exactly how a regression hides.
+# --------------------------------------------------------------------------- #
+# feedgen sets <lastBuildDate> to now() once in the FeedGenerator constructor: stable
+# within a process, but changes between capture runs — regex it out on both sides.
+_LASTBUILDDATE_RE = re.compile(r"<lastBuildDate>.*?</lastBuildDate>", re.DOTALL)
+# feedgen 1.0.0 emits no <generator>; normalized anyway as cheap insurance vs. a lib upgrade.
+_GENERATOR_RE = re.compile(r"<generator>.*?</generator>", re.DOTALL)
+# Merged-post flags are built as list(set(...)) (rss_generator.py:260-265): order depends on
+# PYTHONHASHSEED, which conftest cannot pin. Sort the flag tokens inside each flags div.
+# (This normalization is removed by the stage-2 commit referencing §3.8.)
+_FLAGS_DIV_RE = re.compile(r'<div class="message-flags">(.*?)</div>', re.DOTALL)
+
+
+def _sort_flags_div(match):
+    flags = sorted(p.strip() for p in match.group(1).split("🏷") if p.strip())
+    inner = " ".join("🏷 " + f for f in flags)
+    return f'<div class="message-flags"> {inner} </div>'
+
+
+def normalize_rss(xml):
+    xml = _LASTBUILDDATE_RE.sub("<lastBuildDate/>", xml)
+    xml = _GENERATOR_RE.sub("<generator/>", xml)
+    xml = _FLAGS_DIV_RE.sub(_sort_flags_div, xml)
+    return xml
+
+
+def normalize_html(html):
+    return _FLAGS_DIV_RE.sub(_sort_flags_div, html)
+
+
+def golden_path(channel, kind):
+    ext = {"rss": "rss.xml", "html": "feed.html"}[kind]
+    return os.path.join(GOLDEN_DIR, f"{channel}.{ext}")
+
+
+# --------------------------------------------------------------------------- #
+# Generator entry point: `python -m tests.golden_replay`
+# --------------------------------------------------------------------------- #
+def _bootstrap_standalone():
+    """Reproduce the conftest bootstrap for the standalone generator: repo root on the
+    path, mocked config, UTC timezone."""
+    import sys
+    if ROOT not in sys.path:
+        sys.path.insert(0, ROOT)
+    import tests.mock_config as _mock_config
+    sys.modules["config"] = _mock_config
+    os.environ["TZ"] = "UTC"
+    time.tzset()
+
+
+def generate_all():
+    from _pytest.monkeypatch import MonkeyPatch
+
+    os.makedirs(GOLDEN_DIR, exist_ok=True)
+    for channel in CORPUS_CHANNELS:
+        mp = MonkeyPatch()
+        try:
+            pin_environment(mp)
+            patch_tg_cache(mp, channel)
+            rss = capture_rss(channel)
+            html = capture_html(channel)
+        finally:
+            mp.undo()
+        with open(golden_path(channel, "rss"), "w", encoding="utf-8") as f:
+            f.write(rss)
+        with open(golden_path(channel, "html"), "w", encoding="utf-8") as f:
+            f.write(html)
+        print(f"{channel}: rss={len(rss)}B items={rss.count('<item>')} "
+              f"html={len(html)}B posts={html.count('message-body') if html else 0}")
+
+
+if __name__ == "__main__":
+    _bootstrap_standalone()
+    generate_all()

tests/test_stage0_golden.py

@@ -0,0 +1,77 @@
+# flake8: noqa
+# pylint: disable=missing-function-docstring, redefined-outer-name, line-too-long
+"""Stage-0 golden oracle (render-pipeline refactor epic, issue #27/#34).
+
+Regenerates the RSS + HTML feeds for the frozen recorded corpus and asserts
+byte-equality against the committed goldens after the spec's declared normalizations
+(strip volatile <lastBuildDate>, sort the hash-ordered merged-flags div). Any other
+byte change = a render regression, and this test must catch it.
+
+Guardrails: this stage only ADDS a loader + goldens + this test. No render/pipeline
+production code is touched; the goldens freeze CURRENT behavior including known bugs
+(fixed in later stages, each referencing a §3 registry item).
+
+Regenerate goldens with:  python -m tests.golden_replay
+"""
+import pytest
+
+from tests import golden_replay as gr
+
+
+@pytest.fixture
+def golden_env(monkeypatch):
+    """Apply the determinism pins (signing key, time_based_merge, DB no-op). TZ=UTC is
+    pinned process-wide in conftest."""
+    gr.pin_environment(monkeypatch)
+    return monkeypatch
+
+
+def _read_golden(channel, kind):
+    with open(gr.golden_path(channel, kind), encoding="utf-8") as f:
+        return f.read()
+
+
+@pytest.mark.parametrize("channel", gr.CORPUS_CHANNELS)
+def test_rss_golden(channel, golden_env):
+    gr.patch_tg_cache(golden_env, channel)
+    actual = gr.capture_rss(channel)
+    expected = _read_golden(channel, "rss")
+    assert gr.normalize_rss(actual) == gr.normalize_rss(expected), \
+        f"RSS feed for {channel} diverged from the golden (render regression)"
+
+
+@pytest.mark.parametrize("channel", gr.CORPUS_CHANNELS)
+def test_html_golden(channel, golden_env):
+    gr.patch_tg_cache(golden_env, channel)
+    actual = gr.capture_html(channel)
+    expected = _read_golden(channel, "html")
+    assert gr.normalize_html(actual) == gr.normalize_html(expected), \
+        f"HTML feed for {channel} diverged from the golden (render regression)"
+
+
+def test_all_goldens_present_and_nonempty():
+    """The corpus and its goldens must stay in lockstep — a missing/empty golden would
+    silently pass the parametrized tests only if a channel were also dropped."""
+    import os
+    for channel in gr.CORPUS_CHANNELS:
+        for kind in ("rss", "html"):
+            path = gr.golden_path(channel, kind)
+            assert os.path.exists(path), f"missing golden: {path}"
+            assert os.path.getsize(path) > 0, f"empty golden: {path}"
+
+
+def test_normalization_sorts_merged_flags():
+    """Guard the load-bearing flag-sort normalization itself: merged-post flags are emitted
+    as list(set(...)) (hash-ordered), so the normalizer must canonicalize their order."""
+    unsorted = '<div class="message-flags"> 🏷 video 🏷 fwd 🏷 link </div>'
+    resorted = '<div class="message-flags"> 🏷 link 🏷 fwd 🏷 video </div>'
+    assert gr.normalize_html(unsorted) == gr.normalize_html(resorted)
+    # ...and it is not a no-op that would let a real reordering slip through undetected.
+    assert gr.normalize_html(unsorted) == '<div class="message-flags"> 🏷 fwd 🏷 link 🏷 video </div>'
+
+
+def test_normalization_strips_lastbuilddate():
+    """<lastBuildDate> is the one volatile RSS field (feedgen now() in the constructor)."""
+    a = "<x><lastBuildDate>Mon, 06 Jul 2026 07:32:04 +0000</lastBuildDate><y/></x>"
+    b = "<x><lastBuildDate>Mon, 06 Jul 2026 09:15:59 +0000</lastBuildDate><y/></x>"
+    assert gr.normalize_rss(a) == gr.normalize_rss(b)