Merge remote-tracking branch 'origin/master' into fix/chunk-context-indexed-lookup

# Conflicts:
#	nextcloud_mcp_server/api/visualization.py
#	nextcloud_mcp_server/auth/viz_routes.py

tests/unit/providers/test_mistral.py

@@ -0,0 +1,269 @@
+"""Unit tests for Mistral provider."""
+
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+from mistralai.client.errors import SDKError
+
+from nextcloud_mcp_server.providers.mistral import (
+    BATCH_SIZE,
+    MISTRAL_EMBEDDING_DIMENSIONS,
+    MistralProvider,
+    _is_rate_limit,
+)
+
+
+def _make_data(embedding: list[float], index: int) -> MagicMock:
+    """Build a mock EmbeddingResponseData entry."""
+    item = MagicMock()
+    item.embedding = embedding
+    item.index = index
+    return item
+
+
+def _make_response(embeddings: list[list[float]]) -> MagicMock:
+    """Build a mock EmbeddingResponse with `embeddings` indexed in order."""
+    response = MagicMock()
+    response.data = [_make_data(emb, i) for i, emb in enumerate(embeddings)]
+    return response
+
+
+@pytest.fixture
+def mock_mistral_client(mocker):
+    """Mock the Mistral SDK constructor."""
+    mock_client = MagicMock()
+    mock_client.embeddings = MagicMock()
+    mocker.patch(
+        "nextcloud_mcp_server.providers.mistral.Mistral", return_value=mock_client
+    )
+    return mock_client
+
+
+@pytest.mark.unit
+async def test_mistral_embedding_single(mock_mistral_client):
+    """Single text embed: round-trip through SDK with correct kwargs."""
+    mock_mistral_client.embeddings.create_async = AsyncMock(
+        return_value=_make_response([[0.1, 0.2, 0.3]])
+    )
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    embedding = await provider.embed("hello world")
+
+    assert embedding == [0.1, 0.2, 0.3]
+    mock_mistral_client.embeddings.create_async.assert_awaited_once_with(
+        model="mistral-embed",
+        inputs=["hello world"],
+    )
+
+
+@pytest.mark.unit
+async def test_mistral_embedding_batch_single_call(mock_mistral_client):
+    """Batch smaller than BATCH_SIZE issues a single API call."""
+    mock_mistral_client.embeddings.create_async = AsyncMock(
+        return_value=_make_response([[0.1, 0.2], [0.3, 0.4], [0.5, 0.6]])
+    )
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    embeddings = await provider.embed_batch(["a", "b", "c"])
+
+    assert embeddings == [[0.1, 0.2], [0.3, 0.4], [0.5, 0.6]]
+    assert mock_mistral_client.embeddings.create_async.await_count == 1
+
+
+@pytest.mark.unit
+async def test_mistral_embedding_batch_chunking(mock_mistral_client):
+    """Batches exceeding BATCH_SIZE are split into multiple API calls."""
+
+    # Each call returns one embedding per input it received; capture by side
+    # effect so we can inspect lengths per chunk.
+    def _side_effect(*, model, inputs, **_kwargs):
+        return _make_response([[float(i)] for i in range(len(inputs))])
+
+    mock_mistral_client.embeddings.create_async = AsyncMock(side_effect=_side_effect)
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    total = BATCH_SIZE * 2 + 5  # forces three chunks: 64, 64, 5 (with default)
+    embeddings = await provider.embed_batch([f"text-{i}" for i in range(total)])
+
+    assert len(embeddings) == total
+    assert mock_mistral_client.embeddings.create_async.await_count == 3
+    # Verify the chunk sizes the SDK was actually called with.
+    chunk_sizes = [
+        len(call.kwargs["inputs"])
+        for call in mock_mistral_client.embeddings.create_async.await_args_list
+    ]
+    assert chunk_sizes == [BATCH_SIZE, BATCH_SIZE, 5]
+
+
+@pytest.mark.unit
+async def test_mistral_embedding_batch_order_preserved(mock_mistral_client):
+    """Out-of-order index in response data is sorted before returning."""
+    response = MagicMock()
+    response.data = [
+        _make_data([0.3, 0.3], 2),
+        _make_data([0.1, 0.1], 0),
+        _make_data([0.2, 0.2], 1),
+    ]
+    mock_mistral_client.embeddings.create_async = AsyncMock(return_value=response)
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    embeddings = await provider.embed_batch(["x", "y", "z"])
+
+    assert embeddings == [[0.1, 0.1], [0.2, 0.2], [0.3, 0.3]]
+
+
+@pytest.mark.unit
+async def test_mistral_supports_capabilities(mock_mistral_client):
+    """Mistral provider advertises embeddings only."""
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    assert provider.supports_embeddings is True
+    assert provider.supports_generation is False
+
+
+@pytest.mark.unit
+async def test_mistral_generate_not_implemented(mock_mistral_client):
+    """generate() always raises NotImplementedError."""
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    with pytest.raises(NotImplementedError, match="does not support generation"):
+        await provider.generate("test prompt")
+
+
+@pytest.mark.unit
+async def test_mistral_get_dimension_known_model(mock_mistral_client):
+    """Known model: dimension available without an API call."""
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    assert provider.get_dimension() == MISTRAL_EMBEDDING_DIMENSIONS["mistral-embed"]
+    mock_mistral_client.embeddings.create_async.assert_not_called()
+
+
+@pytest.mark.unit
+async def test_mistral_get_dimension_unknown_model_detected(mock_mistral_client):
+    """Unknown model: dimension detected on first embed() call."""
+    mock_mistral_client.embeddings.create_async = AsyncMock(
+        return_value=_make_response([[0.1] * 768])
+    )
+
+    provider = MistralProvider(api_key="test-key", embedding_model="custom-mistral")
+
+    with pytest.raises(RuntimeError, match="not detected yet"):
+        provider.get_dimension()
+
+    await provider.embed("test")
+    assert provider.get_dimension() == 768
+
+
+@pytest.mark.unit
+async def test_mistral_no_embeddings_disabled(mock_mistral_client):
+    """Setting embedding_model=None disables the embedding capability."""
+    provider = MistralProvider(api_key="test-key", embedding_model=None)
+    assert provider.supports_embeddings is False
+
+    with pytest.raises(NotImplementedError, match="no embedding_model configured"):
+        await provider.embed("test")
+    with pytest.raises(NotImplementedError, match="no embedding_model configured"):
+        await provider.embed_batch(["test"])
+    with pytest.raises(NotImplementedError, match="no embedding_model configured"):
+        provider.get_dimension()
+
+
+@pytest.mark.unit
+async def test_mistral_empty_batch(mock_mistral_client):
+    """An empty batch returns [] without calling the API."""
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    assert await provider.embed_batch([]) == []
+    mock_mistral_client.embeddings.create_async.assert_not_called()
+
+
+@pytest.mark.unit
+async def test_mistral_close_no_error(mock_mistral_client):
+    """close() is best-effort and does not raise."""
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    # No __aexit__ on the mock by default → close() should silently no-op.
+    await provider.close()
+
+
+@pytest.mark.unit
+async def test_mistral_base_url_passed_to_sdk(mocker):
+    """base_url is forwarded as server_url to the Mistral SDK constructor."""
+    mock_ctor = mocker.patch(
+        "nextcloud_mcp_server.providers.mistral.Mistral", return_value=MagicMock()
+    )
+
+    MistralProvider(
+        api_key="test-key",
+        embedding_model="mistral-embed",
+        base_url="https://example.com/mistral",
+    )
+    mock_ctor.assert_called_once_with(
+        api_key="test-key",
+        server_url="https://example.com/mistral",
+    )
+
+
+@pytest.mark.unit
+async def test_mistral_embed_raises_on_empty_response_data(mock_mistral_client):
+    """embed(): empty response.data triggers the defensive RuntimeError guard."""
+    empty_response = MagicMock()
+    empty_response.data = []
+    mock_mistral_client.embeddings.create_async = AsyncMock(return_value=empty_response)
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    with pytest.raises(RuntimeError, match="returned no embedding"):
+        await provider.embed("test")
+
+
+@pytest.mark.unit
+async def test_mistral_embed_raises_on_null_embedding(mock_mistral_client):
+    """embed(): a single response item with embedding=None is rejected."""
+    null_item = MagicMock()
+    null_item.embedding = None
+    null_item.index = 0
+    null_response = MagicMock()
+    null_response.data = [null_item]
+    mock_mistral_client.embeddings.create_async = AsyncMock(return_value=null_response)
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    with pytest.raises(RuntimeError, match="returned no embedding"):
+        await provider.embed("test")
+
+
+@pytest.mark.unit
+async def test_mistral_batch_raises_on_null_embedding(mock_mistral_client):
+    """_embed_batch_request: a null embedding inside a batch raises explicitly."""
+    good = _make_data([0.1, 0.2], 0)
+    bad = MagicMock()
+    bad.embedding = None
+    bad.index = 1
+    response = MagicMock()
+    response.data = [good, bad]
+    mock_mistral_client.embeddings.create_async = AsyncMock(return_value=response)
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    with pytest.raises(RuntimeError, match="null embedding"):
+        await provider.embed_batch(["a", "b"])
+
+
+@pytest.mark.unit
+async def test_mistral_batch_raises_on_count_mismatch(mock_mistral_client):
+    """_embed_batch_request: fewer embeddings returned than inputs sent."""
+    # Two inputs sent, one embedding returned.
+    response = _make_response([[0.1, 0.2]])
+    mock_mistral_client.embeddings.create_async = AsyncMock(return_value=response)
+
+    provider = MistralProvider(api_key="test-key", embedding_model="mistral-embed")
+    with pytest.raises(RuntimeError, match="returned 1 embeddings for 2 inputs"):
+        await provider.embed_batch(["a", "b"])
+
+
+@pytest.mark.unit
+def test_mistral_is_rate_limit_predicate():
+    """_is_rate_limit returns True only for SDKErrors with status_code == 429."""
+    err_429 = MagicMock(spec=SDKError)
+    err_429.status_code = 429
+    err_500 = MagicMock(spec=SDKError)
+    err_500.status_code = 500
+
+    assert _is_rate_limit(err_429) is True
+    assert _is_rate_limit(err_500) is False
+    # ValueError has no status_code attr → getattr returns None → False.
+    assert _is_rate_limit(ValueError()) is False

tests/unit/providers/test_registry.py

@@ -0,0 +1,136 @@
+"""Unit tests for ProviderRegistry — dynaconf-driven auto-detection."""
+
+import pytest
+
+from nextcloud_mcp_server.config import _reload_config
+from nextcloud_mcp_server.providers import (
+    BedrockProvider,
+    MistralProvider,
+    OllamaProvider,
+    OpenAIProvider,
+    SimpleProvider,
+    get_provider,
+    reset_provider,
+)
+from nextcloud_mcp_server.providers.bedrock import BOTO3_AVAILABLE
+
+
+def _clear_provider_envs(monkeypatch: pytest.MonkeyPatch) -> None:
+    """Strip every provider-selection env var so each test starts clean."""
+    for name in (
+        "AWS_REGION",
+        "AWS_ACCESS_KEY_ID",
+        "AWS_SECRET_ACCESS_KEY",
+        "BEDROCK_EMBEDDING_MODEL",
+        "BEDROCK_GENERATION_MODEL",
+        "OPENAI_API_KEY",
+        "OPENAI_BASE_URL",
+        "OPENAI_EMBEDDING_MODEL",
+        "OPENAI_GENERATION_MODEL",
+        "MISTRAL_API_KEY",
+        "MISTRAL_BASE_URL",
+        "MISTRAL_EMBEDDING_MODEL",
+        "OLLAMA_BASE_URL",
+        "OLLAMA_EMBEDDING_MODEL",
+        "OLLAMA_GENERATION_MODEL",
+        "OLLAMA_VERIFY_SSL",
+        "SIMPLE_EMBEDDING_DIMENSION",
+    ):
+        monkeypatch.delenv(name, raising=False)
+
+
+@pytest.fixture
+def clean_provider_env(monkeypatch):
+    """Reset provider singleton + dynaconf cache around each test."""
+    _clear_provider_envs(monkeypatch)
+    reset_provider()
+    _reload_config()
+    yield monkeypatch
+    reset_provider()
+
+
+@pytest.mark.unit
+def test_registry_falls_back_to_simple(clean_provider_env):
+    """No provider env set → SimpleProvider (with default dimension)."""
+    provider = get_provider()
+    assert isinstance(provider, SimpleProvider)
+    assert provider.get_dimension() == 384
+
+
+@pytest.mark.unit
+def test_registry_picks_simple_with_custom_dimension(clean_provider_env):
+    """SIMPLE_EMBEDDING_DIMENSION flows through dynaconf to SimpleProvider."""
+    clean_provider_env.setenv("SIMPLE_EMBEDDING_DIMENSION", "512")
+    _reload_config()
+
+    provider = get_provider()
+    assert isinstance(provider, SimpleProvider)
+    assert provider.get_dimension() == 512
+
+
+@pytest.mark.unit
+def test_registry_picks_mistral_when_api_key_set(clean_provider_env, mocker):
+    """MISTRAL_API_KEY alone is enough to select MistralProvider."""
+    # MistralProvider eagerly constructs the SDK client in __init__; stub it
+    # so the test doesn't depend on the SDK accepting arbitrary keys.
+    mocker.patch("nextcloud_mcp_server.providers.mistral.Mistral")
+    clean_provider_env.setenv("MISTRAL_API_KEY", "test-key")
+    _reload_config()
+
+    provider = get_provider()
+    assert isinstance(provider, MistralProvider)
+
+
+@pytest.mark.unit
+def test_registry_picks_ollama_when_base_url_set(clean_provider_env, mocker):
+    """OLLAMA_BASE_URL selects OllamaProvider."""
+    # OllamaProvider eagerly probes /api/tags in __init__; stub it out.
+    mocker.patch(
+        "nextcloud_mcp_server.providers.ollama.OllamaProvider._check_model_is_loaded"
+    )
+    clean_provider_env.setenv("OLLAMA_BASE_URL", "http://localhost:11434")
+    _reload_config()
+
+    provider = get_provider()
+    assert isinstance(provider, OllamaProvider)
+
+
+@pytest.mark.unit
+def test_registry_openai_wins_over_mistral_and_ollama(clean_provider_env):
+    """OpenAI takes priority when multiple provider env vars are set."""
+    clean_provider_env.setenv("OPENAI_API_KEY", "openai-key")
+    clean_provider_env.setenv("MISTRAL_API_KEY", "mistral-key")
+    clean_provider_env.setenv("OLLAMA_BASE_URL", "http://localhost:11434")
+    _reload_config()
+
+    provider = get_provider()
+    assert isinstance(provider, OpenAIProvider)
+
+
+@pytest.mark.unit
+def test_registry_mistral_wins_over_ollama(clean_provider_env, mocker):
+    """Mistral takes priority over Ollama when both are configured."""
+    # Stub the Mistral SDK constructor for the same reason as the sibling
+    # picker test — keeps the registry test independent of SDK key validation.
+    mocker.patch("nextcloud_mcp_server.providers.mistral.Mistral")
+    clean_provider_env.setenv("MISTRAL_API_KEY", "mistral-key")
+    clean_provider_env.setenv("OLLAMA_BASE_URL", "http://localhost:11434")
+    _reload_config()
+
+    provider = get_provider()
+    assert isinstance(provider, MistralProvider)
+
+
+@pytest.mark.unit
+def test_registry_bedrock_wins_when_aws_region_set(clean_provider_env):
+    """AWS_REGION alone routes to Bedrock, even with other providers configured."""
+    if not BOTO3_AVAILABLE:
+        pytest.skip("boto3 not installed")
+
+    clean_provider_env.setenv("AWS_REGION", "us-east-1")
+    clean_provider_env.setenv("OPENAI_API_KEY", "openai-key")
+    clean_provider_env.setenv("MISTRAL_API_KEY", "mistral-key")
+    _reload_config()
+
+    provider = get_provider()
+    assert isinstance(provider, BedrockProvider)

tests/unit/providers/test_retry.py

@@ -0,0 +1,103 @@
+"""Unit tests for the shared rate-limit retry decorator."""
+
+from unittest.mock import AsyncMock
+
+import pytest
+
+from nextcloud_mcp_server.providers import _retry
+
+
+class _FakeError(Exception):
+    """Stand-in for an SDK exception with an HTTP status code attached."""
+
+    def __init__(self, status_code: int):
+        super().__init__(f"status {status_code}")
+        self.status_code = status_code
+
+
+@pytest.fixture(autouse=True)
+def _no_real_sleep(monkeypatch):
+    """Replace anyio.sleep with an awaitable no-op so retries don't waste time."""
+    monkeypatch.setattr(_retry.anyio, "sleep", AsyncMock(return_value=None))
+
+
+@pytest.mark.unit
+async def test_retry_succeeds_after_429():
+    """A 429 followed by success returns the success value."""
+    calls = {"n": 0}
+
+    @_retry.retry_on_rate_limit(
+        _FakeError, is_rate_limit=lambda e: e.status_code == 429
+    )
+    async def flaky():
+        calls["n"] += 1
+        if calls["n"] < 3:
+            raise _FakeError(429)
+        return "ok"
+
+    result = await flaky()
+    assert result == "ok"
+    assert calls["n"] == 3
+
+
+@pytest.mark.unit
+async def test_retry_reraises_non_rate_limit_immediately():
+    """A non-rate-limit error of the same class is re-raised on first hit."""
+    calls = {"n": 0}
+
+    @_retry.retry_on_rate_limit(
+        _FakeError, is_rate_limit=lambda e: e.status_code == 429
+    )
+    async def boom():
+        calls["n"] += 1
+        raise _FakeError(500)
+
+    with pytest.raises(_FakeError, match="status 500"):
+        await boom()
+    assert calls["n"] == 1  # No retries on non-429.
+
+
+@pytest.mark.unit
+async def test_retry_gives_up_after_max_retries():
+    """After MAX_RETRIES failed attempts the last error is re-raised."""
+    calls = {"n": 0}
+
+    @_retry.retry_on_rate_limit(
+        _FakeError, is_rate_limit=lambda e: e.status_code == 429
+    )
+    async def always_429():
+        calls["n"] += 1
+        raise _FakeError(429)
+
+    with pytest.raises(_FakeError, match="status 429"):
+        await always_429()
+    assert calls["n"] == _retry.MAX_RETRIES
+
+
+@pytest.mark.unit
+async def test_retry_default_predicate_treats_all_as_rate_limit():
+    """Default predicate (`lambda _: True`) retries every caught exception."""
+    calls = {"n": 0}
+
+    @_retry.retry_on_rate_limit(_FakeError)
+    async def fail_once():
+        calls["n"] += 1
+        if calls["n"] < 2:
+            raise _FakeError(503)
+        return "recovered"
+
+    result = await fail_once()
+    assert result == "recovered"
+    assert calls["n"] == 2
+
+
+@pytest.mark.unit
+async def test_retry_does_not_catch_unrelated_exceptions():
+    """Exceptions of a different class bypass the decorator entirely."""
+
+    @_retry.retry_on_rate_limit(_FakeError)
+    async def value_error():
+        raise ValueError("nope")
+
+    with pytest.raises(ValueError, match="nope"):
+        await value_error()

tests/unit/search/test_pdf_highlighter_bbox.py

@@ -0,0 +1,232 @@
+"""Unit tests for PDFHighlighter.compute_chunk_bboxes_batch (Deck #76).
+
+Replaces the legacy `highlight_chunks_batch`-+-base64 pipeline that inflated
+Qdrant payloads with per-chunk PNG screenshots. The new path returns
+normalized bounding boxes only.
+"""
+
+from __future__ import annotations
+
+import pymupdf
+import pytest
+
+from nextcloud_mcp_server.search.pdf_highlighter import PDFHighlighter
+
+
+def _make_pdf(pages: list[str]) -> bytes:
+    """Build an in-memory PDF whose pages contain the given text."""
+    doc = pymupdf.open()
+    for body in pages:
+        page = doc.new_page(width=595, height=842)  # A4
+        page.insert_text((50, 50), body)
+    pdf_bytes = doc.tobytes()
+    doc.close()
+    return pdf_bytes
+
+
+def _page_boundaries(pages: list[str]) -> tuple[list[dict], str]:
+    """Build (page_boundaries, full_text) compatible with the highlighter API."""
+    boundaries: list[dict] = []
+    cursor = 0
+    parts: list[str] = []
+    for i, body in enumerate(pages, start=1):
+        end = cursor + len(body)
+        boundaries.append({"page": i, "start_offset": cursor, "end_offset": end})
+        parts.append(body)
+        cursor = end
+    return boundaries, "".join(parts)
+
+
+@pytest.mark.unit
+def test_compute_chunk_bboxes_returns_normalized_rects():
+    """Each returned bbox should be 4 floats in [0, 1] tagged with the page."""
+    pages = [
+        "Chapter 1: Introduction. Nextcloud is a self-hosted collaboration platform "
+        "covering installation, configuration and maintenance topics.",
+        "Chapter 2: Installation. Download the package, extract it to the web "
+        "server directory, and configure the database connection.",
+    ]
+    pdf_bytes = _make_pdf(pages)
+    boundaries, full_text = _page_boundaries(pages)
+
+    chunks = [
+        (
+            0,
+            0,
+            len(pages[0]),
+            1,
+            "Chapter 1: Introduction. Nextcloud is a self-hosted collaboration platform.",
+        ),
+        (
+            1,
+            len(pages[0]),
+            len(pages[0]) + len(pages[1]),
+            2,
+            "Chapter 2: Installation. Download the package.",
+        ),
+    ]
+
+    results = PDFHighlighter.compute_chunk_bboxes_batch(
+        pdf_bytes=pdf_bytes,
+        chunks=chunks,
+        page_boundaries=boundaries,
+        full_text=full_text,
+    )
+
+    assert set(results) == {0, 1}
+
+    bboxes_p1, page_p1 = results[0]
+    bboxes_p2, page_p2 = results[1]
+
+    assert page_p1 == 1
+    assert page_p2 == 2
+
+    for rects in (bboxes_p1, bboxes_p2):
+        assert len(rects) >= 1
+        for rect in rects:
+            assert len(rect) == 4
+            x0, y0, x1, y1 = rect
+            assert 0.0 <= x0 < x1 <= 1.0
+            assert 0.0 <= y0 < y1 <= 1.0
+
+
+@pytest.mark.unit
+def test_compute_chunk_bboxes_empty_input():
+    assert (
+        PDFHighlighter.compute_chunk_bboxes_batch(
+            pdf_bytes=b"",
+            chunks=[],
+            page_boundaries=[],
+            full_text="",
+        )
+        == {}
+    )
+
+
+@pytest.mark.unit
+def test_compute_chunk_bboxes_omits_when_offsets_out_of_range():
+    """Chunks whose offsets fall outside every page boundary are omitted.
+
+    Verifies the docstring contract: *"Chunks whose bbox cannot be located
+    are omitted from the result."* (path: ``find_chunk_page`` returns None).
+    """
+    pages = ["Page one body text content here for the test."]
+    pdf_bytes = _make_pdf(pages)
+    boundaries, full_text = _page_boundaries(pages)
+
+    # Offsets way beyond the document end — no page boundary matches.
+    out_of_range_start = len(full_text) + 1000
+    out_of_range_end = out_of_range_start + 50
+    chunks = [(0, out_of_range_start, out_of_range_end, 1, "irrelevant")]
+
+    results = PDFHighlighter.compute_chunk_bboxes_batch(
+        pdf_bytes=pdf_bytes,
+        chunks=chunks,
+        page_boundaries=boundaries,
+        full_text=full_text,
+    )
+
+    assert results == {}
+
+
+@pytest.mark.unit
+def test_compute_chunk_bboxes_omits_when_text_not_in_pdf():
+    """Chunks whose page-relative text isn't on the page are omitted.
+
+    Verifies the second omission path: ``_find_chunk_bbox`` returns None
+    when the supplied text cannot be located on the rendered page.
+    """
+    pages = ["Hello world."]
+    pdf_bytes = _make_pdf(pages)
+    # Build boundaries from the real text but pass a *different* full_text
+    # so the page-relative slice is content that does not exist in the PDF.
+    boundaries, _ = _page_boundaries(pages)
+    bogus_full_text = "Z" * len(pages[0])
+
+    chunks = [(0, 0, len(pages[0]), 1, "ignored")]
+
+    results = PDFHighlighter.compute_chunk_bboxes_batch(
+        pdf_bytes=pdf_bytes,
+        chunks=chunks,
+        page_boundaries=boundaries,
+        full_text=bogus_full_text,
+    )
+
+    assert results == {}
+
+
+@pytest.mark.unit
+@pytest.mark.parametrize("page_index", [0, 1])
+def test_compute_chunk_bboxes_assigns_correct_page(page_index: int):
+    """Verify the page number returned matches the page the chunk lives on."""
+    pages = [
+        "Page one talks about apples and oranges in detail.",
+        "Page two discusses bananas and grapes thoroughly.",
+    ]
+    pdf_bytes = _make_pdf(pages)
+    boundaries, full_text = _page_boundaries(pages)
+
+    if page_index == 0:
+        chunk_text = "apples and oranges"
+        offsets = (0, len(pages[0]))
+    else:
+        chunk_text = "bananas and grapes"
+        offsets = (len(pages[0]), len(pages[0]) + len(pages[1]))
+
+    chunks = [(0, offsets[0], offsets[1], page_index + 1, chunk_text)]
+
+    results = PDFHighlighter.compute_chunk_bboxes_batch(
+        pdf_bytes=pdf_bytes,
+        chunks=chunks,
+        page_boundaries=boundaries,
+        full_text=full_text,
+    )
+
+    assert results, "expected a bbox for the chunk"
+    _, page_num = results[0]
+    assert page_num == page_index + 1
+
+
+@pytest.mark.unit
+def test_compute_chunk_bboxes_handles_unordered_page_boundaries():
+    """Page lookup must match by ``page`` key, not by list position.
+
+    Regression guard: an earlier implementation indexed
+    ``page_boundaries[page_num - 1]``, which silently produces a wrong
+    bbox if boundaries are passed out of order. Reverse the boundaries
+    and assert the result is identical to the in-order case.
+    """
+    pages = [
+        "Page one talks about apples and oranges in detail.",
+        "Page two discusses bananas and grapes thoroughly.",
+    ]
+    pdf_bytes = _make_pdf(pages)
+    boundaries, full_text = _page_boundaries(pages)
+
+    chunks = [
+        (0, 0, len(pages[0]), 1, "apples and oranges"),
+        (
+            1,
+            len(pages[0]),
+            len(pages[0]) + len(pages[1]),
+            2,
+            "bananas and grapes",
+        ),
+    ]
+
+    in_order = PDFHighlighter.compute_chunk_bboxes_batch(
+        pdf_bytes=pdf_bytes,
+        chunks=chunks,
+        page_boundaries=boundaries,
+        full_text=full_text,
+    )
+    reversed_order = PDFHighlighter.compute_chunk_bboxes_batch(
+        pdf_bytes=pdf_bytes,
+        chunks=chunks,
+        page_boundaries=list(reversed(boundaries)),
+        full_text=full_text,
+    )
+
+    assert in_order == reversed_order
+    assert reversed_order[0][1] == 1
+    assert reversed_order[1][1] == 2