test: cover by-chunk span and line-range resolve

surfsense_backend/tests/integration/test_documents_by_chunk_route.py

@@ -0,0 +1,127 @@
+"""Phase E.1 contract: the by-chunk resolve API exposes chunk char spans and
+derives the cited chunk's line range from source_markdown."""
+
+import pytest
+import pytest_asyncio
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.db import Chunk, Document, DocumentStatus, DocumentType, SearchSpace, User
+
+pytestmark = pytest.mark.integration
+
+_BODY = "alpha\nbravo\ncharlie\ndelta"
+
+
+async def _make_document(
+    session: AsyncSession,
+    search_space: SearchSpace,
+    user: User,
+    *,
+    source_markdown: str = _BODY,
+) -> Document:
+    doc = Document(
+        title="Doc",
+        document_type=DocumentType.FILE,
+        document_metadata={},
+        content=source_markdown,
+        content_hash="hash-by-chunk",
+        source_markdown=source_markdown,
+        search_space_id=search_space.id,
+        created_by_id=user.id,
+        status=DocumentStatus.ready(),
+    )
+    session.add(doc)
+    await session.flush()
+    return doc
+
+
+async def _add_chunk(
+    session: AsyncSession,
+    document: Document,
+    *,
+    content: str,
+    position: int,
+    start_char: int | None,
+    end_char: int | None,
+) -> Chunk:
+    chunk = Chunk(
+        content=content,
+        position=position,
+        document_id=document.id,
+        start_char=start_char,
+        end_char=end_char,
+    )
+    session.add(chunk)
+    await session.flush()
+    return chunk
+
+
+@pytest_asyncio.fixture
+async def make_document(db_session, db_search_space, db_user):
+    async def _make(**overrides):
+        return await _make_document(db_session, db_search_space, db_user, **overrides)
+
+    return _make
+
+
+async def test_cited_line_range_derived_from_spans(
+    db_session, db_search_space, db_user, make_document
+):
+    from app.routes.documents_routes import get_document_by_chunk_id
+
+    doc = await make_document()
+    await _add_chunk(
+        db_session, doc, content="alpha\nbravo\n", position=0, start_char=0, end_char=12
+    )
+    cited = await _add_chunk(
+        db_session,
+        doc,
+        content="charlie\ndelta",
+        position=1,
+        start_char=12,
+        end_char=len(_BODY),
+    )
+
+    result = await get_document_by_chunk_id(
+        cited.id, chunk_window=5, session=db_session, user=db_user
+    )
+
+    assert result.cited_start_line == 3
+    assert result.cited_end_line == 4
+
+
+async def test_chunk_spans_exposed_in_response(
+    db_session, db_search_space, db_user, make_document
+):
+    from app.routes.documents_routes import get_document_by_chunk_id
+
+    doc = await make_document()
+    cited = await _add_chunk(
+        db_session, doc, content="alpha\nbravo\n", position=0, start_char=0, end_char=12
+    )
+
+    result = await get_document_by_chunk_id(
+        cited.id, chunk_window=5, session=db_session, user=db_user
+    )
+
+    chunk = next(c for c in result.chunks if c.id == cited.id)
+    assert chunk.start_char == 0
+    assert chunk.end_char == 12
+
+
+async def test_cited_line_range_null_without_spans(
+    db_session, db_search_space, db_user, make_document
+):
+    from app.routes.documents_routes import get_document_by_chunk_id
+
+    doc = await make_document()
+    cited = await _add_chunk(
+        db_session, doc, content="alpha", position=0, start_char=None, end_char=None
+    )
+
+    result = await get_document_by_chunk_id(
+        cited.id, chunk_window=5, session=db_session, user=db_user
+    )
+
+    assert result.cited_start_line is None
+    assert result.cited_end_line is None