brain-of-reese/tests/e2e/test_sources_midstream_bug.py

"""Phase 20 E2E (Playwright): navigating away mid-turn keeps the answer.

Story: ``.agent/user_stories/sources-midstream.md``
Bug report (TODO.md L3): *"Clicking "sources" while chat is generating
clears chat and result will never show up."*
Run in isolation (DB must be up: ``podman compose up -d db``):

    uv run pytest tests/e2e/test_sources_midstream_bug.py -v --no-cov

The bug: the brain message persisted only on ``done``, so leaving the
chat page while a turn was in flight aborted the stream and dropped
whatever had already streamed — the user came back to their own question
with no result, ever. The fix (phase 20, owner-confirmed A1): a single
``pagehide`` save point in app.js persists the partial raw answer (via
the existing ``rememberBrainTurn`` helper) when navigation hits a turn
that is in flight and has already streamed text.

Timing is deterministic by construction:

* scenario 1 keys off the mock's ``write a long answer`` trigger — a
  ~5400-char / ~450-frame / ~9s content stream, so the navigation lands
  mid-stream with a wide margin;
* scenario 2 keys off the mock's ``think out loud then hesitate``
  trigger — the phase-17 thinking stream followed by a 4s silence before
  the first content frame, so the navigation lands inside pure thinking;
* scenarios 3 and 4 settle the turn fully (send button re-enabled)
  before any navigation.

Test → story mapping (Playwright Mapping Rule):
1. ``test_partial_answer_survives_sources_nav_midstream``
2. ``test_no_orphan_brain_message_when_navigated_before_first_token``
3. ``test_completed_turn_unaffected``
4. ``test_new_chat_still_clears_conversation``
"""
from __future__ import annotations

import asyncio
import json
import re
from collections.abc import Iterator
from pathlib import Path
from threading import Thread
from typing import Any

import pytest
from playwright.sync_api import Page, expect
from sqlalchemy import text

from app.config import Settings
from app.db import SessionLocal
from app.rag.importer import ImportSummary, import_sources
from app.rag.llm import LLMClient
from e2e.auth_helpers import login
from e2e.mock_llm import long_answer

REPO = Path(__file__).resolve().parents[2]
FIXTURES = REPO / "tests" / "fixtures" / "docs"
QUESTION = "How is my Kubernetes cluster set up?"
MOCK_ANSWER_MARKER = "Deterministic mock answer for E2E"
STORAGE_KEY = "bor.chat.v1"

# --- scenario 1: a turn that is guaranteed to still be in flight --------
#: The mock's long-answer trigger (~9s content stream at 0.02s/frame).
LONG_QUESTION = "write a long answer about how my kubernetes cluster is set up"
FULL_LONG = long_answer()
#: The mock's first 12-char content slice (the same cut ``_sse_stream``
#: makes) — the stored partial must START with it (raw text, pre-render).
FIRST_CHUNK_RAW = re.findall(r".{1,12}", FULL_LONG, re.S)[0]
#: The rendered form of those first frames: the shared escape-first
#: markdown renderer converts the "1. " numbered line into a list item,
#: dropping the marker (pinned by test_long_answers).
FIRST_LINE_DOM = "Step 1: configure node-1"

# --- scenario 2: navigation during pure thinking (no answer tokens) -----
HESITATE_QUESTION = (
    "think out loud then hesitate — how is my kubernetes cluster set up?"
)
#: Tail of the mock's deterministic scratchpad (mock_llm.compose_thinking)
#: — when it is rendered, the thinking stream has just ended and the 4s
#: pre-content pause (SLOW_PRETOKEN_TRIGGER) is running.
THINKING_TAIL = "nothing is invented"

#: Phase-10 viewer URL + phase-13 back=/ (byte-identical to the chip the
#: persistence suite pins — grounded-turn sources are unchanged by 20).
CHIP_HREF = "/document.html?source=docs&path=homelab%2Fkubernetes.md&back=%2F"


async def _import_fixtures(mock_port: int) -> ImportSummary:
    kwargs: dict[str, Any] = {"_env_file": None, "llm_base_url": f"http://127.0.0.1:{mock_port}/v1"}
    settings = Settings(**kwargs)  # pyright: ignore[reportCallIssue]
    return await import_sources([FIXTURES], LLMClient(settings))


def _run_in_thread(coro: Any) -> Any:
    """Run a coroutine on a worker thread.

    Playwright's sync API keeps an asyncio loop running on the test thread,
    so ``asyncio.run`` cannot be called directly from a test body.
    """
    box: dict[str, Any] = {}

    def runner() -> None:
        try:
            box["value"] = asyncio.run(coro)
        except BaseException as e:  # noqa: BLE001 — re-raised on the test thread
            box["error"] = e

    t = Thread(target=runner)
    t.start()
    t.join()
    if "error" in box:
        raise box["error"]
    return box["value"]


def _reset_db(mock_port: int, seed: bool) -> ImportSummary | None:
    """Truncate the KB (and query log), then optionally re-import fixtures."""
    with SessionLocal() as db:
        db.execute(text("TRUNCATE chunks, documents, query_log"))
        db.commit()
    if not seed:
        return None
    return _run_in_thread(_import_fixtures(mock_port))


def _stored(page: Page) -> str | None:
    """Raw localStorage payload for the chat (None when the key is absent)."""
    return page.evaluate(f"() => localStorage.getItem('{STORAGE_KEY}')")


def _stored_parsed(page: Page) -> dict[str, Any]:
    raw = _stored(page)
    assert raw is not None, "the conversation key must exist in localStorage"
    return json.loads(raw)


def _ask(page: Page, question: str) -> None:
    """Send one turn and wait until the grounded answer has fully landed."""
    page.fill("#message-input", question)
    page.click("#send-btn")
    expect(page.locator(".msg.user .bubble").last).to_contain_text(question)
    expect(page.locator(".msg.brain .bubble").last).to_contain_text(
        MOCK_ANSWER_MARKER, timeout=30_000
    )
    expect(page.locator("#send-btn")).to_be_enabled()
    expect(page.locator("#send-label")).to_have_text("Send")


def _no_error_banner(page: Page) -> None:
    """The never-stale contract: a restored/partial state must never
    present an error banner (role=alert) — the turn is simply partial."""
    expect(page.locator('[role="alert"]')).to_have_count(0)


@pytest.fixture()
def seeded_kb(mock_llm: int, db_ready: None) -> Iterator[None]:
    """A fresh KB seeded from ``tests/fixtures/docs`` (13 docs since phase
    47, A9 formats), truncated again on teardown. ``db_ready`` (conftest)
    skips with clear instructions when Postgres is down."""
    summary = _reset_db(mock_llm, seed=True)
    assert summary is not None and summary.added == 13
    yield
    _reset_db(mock_llm, seed=False)


# ---------------------------------------------------------------------------
# 1. Mid-stream navigation via the Sources nav link: the partial answer
#    that had already streamed is persisted and restored
# ---------------------------------------------------------------------------


def test_partial_answer_survives_sources_nav_midstream(
    page: Page, app_url: str, seeded_kb: None
) -> None:
    page.set_default_timeout(30_000)
    # Admin (phase 16/19): only the admin sees the #nav-sources link the
    # bug report clicks.
    login(page, app_url, next="/")
    expect(page.locator("#nav-sources")).to_be_visible()

    # Start the ~9s long answer.
    page.fill("#message-input", LONG_QUESTION)
    page.click("#send-btn")
    expect(page.locator(".msg.user .bubble").last).to_contain_text(LONG_QUESTION)

    # Wait until the first streamed frames have rendered (the first line,
    # in its list-rendered form) — the turn is now provably mid-stream.
    bubble = page.locator(".msg.brain .bubble").last
    expect(bubble).to_contain_text(FIRST_LINE_DOM, timeout=30_000)
    # The turn is still in flight (the stream runs ~9s; navigation takes
    # well under that).
    expect(page.locator("#send-btn")).to_be_disabled()

    # THE BUG REPORT, VERBATIM: click "Sources" while chat is generating.
    page.click("#nav-sources")
    expect(page).to_have_url(app_url + "/sources.html")
    # The navigation really landed on the admin catalog (mid-stream state
    # of the stream itself does not matter to the page — the fetch is
    # aborted by the unload, which is the point).
    expect(page.locator("#docs-tbody tr").first).to_be_visible(timeout=15_000)

    # Return to the chat.
    page.goto(app_url + "/")

    # The question AND the already-streamed partial answer are both
    # rendered — no empty state, no error banner.
    expect(page.locator("#empty-state")).to_be_hidden()
    expect(page.locator(".msg.user .bubble")).to_have_count(1)
    expect(page.locator(".msg.user .bubble").first).to_contain_text(LONG_QUESTION)
    restored = page.locator(".msg.brain .bubble")
    expect(restored).to_have_count(1)
    expect(restored.first).to_contain_text(FIRST_LINE_DOM)
    _no_error_banner(page)

    # Storage holds the partial as a plain brain message: raw text starting
    # with the first streamed chunk — and SHORTER than the full answer
    # (navigation landed mid-stream), with no done metadata (no
    # sources/deflected/suggestions/thinking: this turn had none and a
    # partial never carries the done fields).
    msgs = _stored_parsed(page)["messages"]
    assert [m["who"] for m in msgs] == ["user", "brain"]
    assert msgs[0]["text"] == LONG_QUESTION
    brain = msgs[1]
    assert brain["text"].startswith(FIRST_CHUNK_RAW)
    assert len(brain["text"]) < len(FULL_LONG), "the stored answer must be partial"
    assert brain["text"] != FULL_LONG
    assert "sources" not in brain
    assert "deflected" not in brain
    assert "suggestions" not in brain
    assert "thinking" not in brain

    # The partial renders like any brain message (the existing
    # bubble contract — no new surface) and is tunable like one.
    expect(page.locator("details.thinking")).to_have_count(0)
    expect(page.locator(".msg.brain .source-chip")).to_have_count(0)


# ---------------------------------------------------------------------------
# 2. Navigation BEFORE the first answer token (pure thinking): nothing
#    brain-side is persisted — the question comes back alone
# ---------------------------------------------------------------------------


def test_no_orphan_brain_message_when_navigated_before_first_token(
    page: Page, app_url: str, seeded_kb: None
) -> None:
    page.set_default_timeout(30_000)
    page.goto(app_url)
    page.fill("#message-input", HESITATE_QUESTION)
    page.click("#send-btn")
    expect(page.locator(".msg.user .bubble").last).to_contain_text(HESITATE_QUESTION)

    # Wait until the scratchpad's tail is rendered (phase-17 thinking body,
    # ~2 700 chars / ≈4.5s, lengthened in phase 21) — the 4s pre-content
    # pause (SLOW_PRETOKEN_TRIGGER) is now running, so the navigation below
    # lands inside pure thinking with a wide margin.
    thinking = page.locator(".msg.brain").last.locator("details.thinking")
    thinking.wait_for(state="attached", timeout=10_000)
    expect(thinking.locator(".thinking-text")).to_contain_text(THINKING_TAIL)
    # Still pre-token: the button is busy with the Thinking state.
    expect(page.locator("#send-btn")).to_be_disabled()
    expect(page.locator("#send-label")).to_have_text("Thinking…")

    # Leave during the pause (no answer token has streamed — acc is empty,
    # so the pagehide save point must persist nothing brain-side).
    page.goto(app_url + "/sources.html")

    # Return to the chat.
    page.goto(app_url + "/")

    # The question is restored — with NO brain message behind it: no empty
    # bubble, no partial, no thinking block (owner-confirmed A1.2).
    expect(page.locator("#empty-state")).to_be_hidden()
    expect(page.locator(".msg.user .bubble")).to_have_count(1)
    expect(page.locator(".msg.user .bubble").first).to_contain_text(HESITATE_QUESTION)
    expect(page.locator(".msg")).to_have_count(1)
    expect(page.locator(".msg.brain")).to_have_count(0)
    expect(page.locator("details.thinking")).to_have_count(0)
    _no_error_banner(page)

    # Storage agrees: exactly the user message, nothing brain-side.
    msgs = _stored_parsed(page)["messages"]
    assert len(msgs) == 1
    assert msgs[0] == {"who": "user", "text": HESITATE_QUESTION}


# ---------------------------------------------------------------------------
# 3. Completed turn: the done save point is byte-identical to before —
#    the new pagehide save point must not duplicate or alter it
# ---------------------------------------------------------------------------


def test_completed_turn_unaffected(
    page: Page, app_url: str, seeded_kb: None
) -> None:
    page.set_default_timeout(30_000)
    page.goto(app_url)
    _ask(page, QUESTION)

    # The done save point: full answer + metadata, exactly as phase 14.
    before = _stored_parsed(page)
    assert [m["who"] for m in before["messages"]] == ["user", "brain"]
    brain = before["messages"][1]
    assert MOCK_ANSWER_MARKER in brain["text"]
    assert brain["deflected"] is False
    assert any(s["path"] == "homelab/kubernetes.md" for s in brain["sources"])

    # A trip to Sources and back (the turn finished long ago — uiState is
    # idle, so the pagehide save point must be a no-op).
    page.goto(app_url + "/sources.html")
    page.goto(app_url + "/")

    # Full answer + source chip rendered; no error banner.
    expect(page.locator("#empty-state")).to_be_hidden()
    expect(page.locator(".msg.user .bubble")).to_contain_text(QUESTION)
    bubble = page.locator(".msg.brain .bubble")
    expect(bubble).to_have_count(1)
    expect(bubble.first).to_contain_text(MOCK_ANSWER_MARKER)
    chip = page.locator(".msg.brain .source-chip", has_text="kubernetes.md")
    expect(chip).to_have_count(1)
    expect(chip.first).to_have_attribute("href", CHIP_HREF)
    _no_error_banner(page)

    # Storage is byte-identical to the pre-navigation payload — the
    # completed turn persisted exactly as before (one brain message, done
    # metadata intact; no duplicate from the pagehide path).
    assert _stored_parsed(page) == before


# ---------------------------------------------------------------------------
# 4. The DELIBERATE clear is untouched: New Chat from the sources page
#    still clears the conversation (phase 14/19 contract)
# ---------------------------------------------------------------------------


def test_new_chat_still_clears_conversation(
    page: Page, app_url: str, seeded_kb: None
) -> None:
    page.set_default_timeout(30_000)
    page.goto(app_url)
    _ask(page, QUESTION)
    assert _stored(page) is not None

    # To the sources page (anonymous is fine — the shared bar carries the
    # New Chat control regardless of auth, phase 19).
    page.goto(app_url + "/sources.html")
    new_chat = page.locator("#new-chat-btn")
    expect(new_chat).to_be_visible()
    new_chat.click()

    # "New chat" on a non-chat page means "go to the chat, fresh": the
    # land page shows the empty state and the conversation key is GONE —
    # the deliberate clearChatStorage() is unaffected by the phase-20
    # pagehide save point.
    expect(page).to_have_url(app_url + "/")
    expect(page.locator("#empty-state")).to_be_visible()
    expect(page.locator(".msg")).to_have_count(0)
    assert _stored(page) is None, "New Chat must clear the localStorage key"
    _no_error_banner(page)