Infinite scroll lazy load document list in inspector

haiku_rag_slim/haiku/rag/inspector/widgets/document_list.py

@@ -7,6 +7,8 @@ from textual.widgets import ListItem, ListView, Static
 from haiku.rag.client import HaikuRAG
 from haiku.rag.store.models import Document
 
+BATCH_SIZE = 50
+
 
 class DocumentList(VerticalScroll):  # pragma: no cover
     """Widget for displaying and browsing documents."""
@@ -24,6 +26,9 @@ class DocumentList(VerticalScroll):  # pragma: no cover
         super().__init__(**kwargs)
         self.documents: list[Document] = []
         self.list_view = ListView()
+        self.has_more: bool = True
+        self._client: HaikuRAG | None = None
+        self._loading: bool = False
 
     def compose(self) -> ComposeResult:
         """Compose the document list."""
@@ -31,13 +36,29 @@ class DocumentList(VerticalScroll):  # pragma: no cover
         yield self.list_view
 
     async def load_documents(self, client: HaikuRAG) -> None:
-        """Load all documents from the database."""
-        self.documents = await client.list_documents(limit=None)
+        """Load initial batch of documents from the database."""
+        self._client = client
+        self.documents = await client.list_documents(limit=BATCH_SIZE, offset=0)
+        self.has_more = len(self.documents) >= BATCH_SIZE
         await self.list_view.clear()
         for doc in self.documents:
             title = doc.title or doc.uri or doc.id
             await self.list_view.append(ListItem(Static(f"{title}")))
 
+    async def load_more(self, client: HaikuRAG) -> None:
+        """Load the next batch of documents."""
+        if not self.has_more or self._loading:
+            return
+        self._loading = True
+        offset = len(self.documents)
+        new_docs = await client.list_documents(limit=BATCH_SIZE, offset=offset)
+        self.has_more = len(new_docs) >= BATCH_SIZE
+        self.documents.extend(new_docs)
+        for doc in new_docs:
+            title = doc.title or doc.uri or doc.id
+            await self.list_view.append(ListItem(Static(f"{title}")))
+        self._loading = False
+
     @on(ListView.Highlighted)
     @on(ListView.Selected)
     async def handle_document_selection(
@@ -49,3 +70,6 @@ class DocumentList(VerticalScroll):  # pragma: no cover
         idx = event.list_view.index
         if idx is not None and 0 <= idx < len(self.documents):
             self.post_message(self.DocumentSelected(self.documents[idx]))
+            # Infinite scroll: load more when near the end
+            if self._client and self.has_more and idx >= len(self.documents) - 10:
+                await self.load_more(self._client)

tests/test_inspector.py

@@ -1,8 +1,10 @@
-from unittest.mock import patch
+from unittest.mock import AsyncMock, patch
 
+import pytest
 from typer.testing import CliRunner
 
 from haiku.rag.cli import cli
+from haiku.rag.store.models import Document
 
 runner = CliRunner()
 
@@ -16,3 +18,115 @@ def test_inspect_command():
 
         assert result.exit_code == 0
         mock_inspector.assert_called_once()
+
+
+@pytest.mark.asyncio
+async def test_document_list_loads_initial_batch():
+    """Test that DocumentList loads only the initial batch on startup."""
+    from textual.app import App
+
+    from haiku.rag.inspector.widgets.document_list import DocumentList
+
+    # Create mock documents
+    mock_docs = [
+        Document(id=f"doc-{i}", content=f"Content {i}", title=f"Doc {i}")
+        for i in range(50)
+    ]
+
+    class TestApp(App):
+        def compose(self):
+            yield DocumentList(id="doc-list")
+
+    app = TestApp()
+    async with app.run_test():
+        doc_list = app.query_one(DocumentList)
+
+        # Create mock client
+        mock_client = AsyncMock()
+        mock_client.list_documents = AsyncMock(return_value=mock_docs)
+
+        await doc_list.load_documents(mock_client)
+
+        # Should have called list_documents with a limit (not None)
+        mock_client.list_documents.assert_called_once()
+        call_kwargs = mock_client.list_documents.call_args
+        # The limit should be set (not None) for initial load
+        assert call_kwargs.kwargs.get("limit") is not None
+
+
+@pytest.mark.asyncio
+async def test_document_list_load_more():
+    """Test that DocumentList can load more documents."""
+    from textual.app import App
+
+    from haiku.rag.inspector.widgets.document_list import DocumentList
+
+    # Create mock documents - two batches
+    batch1 = [
+        Document(id=f"doc-{i}", content=f"Content {i}", title=f"Doc {i}")
+        for i in range(50)
+    ]
+    batch2 = [
+        Document(id=f"doc-{i}", content=f"Content {i}", title=f"Doc {i}")
+        for i in range(50, 100)
+    ]
+
+    class TestApp(App):
+        def compose(self):
+            yield DocumentList(id="doc-list")
+
+    app = TestApp()
+    async with app.run_test():
+        doc_list = app.query_one(DocumentList)
+
+        mock_client = AsyncMock()
+        mock_client.list_documents = AsyncMock(side_effect=[batch1, batch2])
+
+        # Load initial batch
+        await doc_list.load_documents(mock_client)
+        assert len(doc_list.documents) == 50
+
+        # Load more
+        await doc_list.load_more(mock_client)
+        assert len(doc_list.documents) == 100
+
+        # Verify offset was used in second call
+        second_call = mock_client.list_documents.call_args_list[1]
+        assert second_call.kwargs.get("offset") == 50
+
+
+@pytest.mark.asyncio
+async def test_document_list_tracks_has_more():
+    """Test that DocumentList tracks whether more documents are available."""
+    from textual.app import App
+
+    from haiku.rag.inspector.widgets.document_list import DocumentList
+
+    # First batch returns full page, second returns partial
+    batch1 = [
+        Document(id=f"doc-{i}", content=f"Content {i}", title=f"Doc {i}")
+        for i in range(50)
+    ]
+    batch2 = [
+        Document(id=f"doc-{i}", content=f"Content {i}", title=f"Doc {i}")
+        for i in range(50, 60)
+    ]
+
+    class TestApp(App):
+        def compose(self):
+            yield DocumentList(id="doc-list")
+
+    app = TestApp()
+    async with app.run_test():
+        doc_list = app.query_one(DocumentList)
+
+        mock_client = AsyncMock()
+        mock_client.list_documents = AsyncMock(side_effect=[batch1, batch2])
+
+        await doc_list.load_documents(mock_client)
+        # After loading full batch, has_more should be True
+        assert doc_list.has_more is True
+
+        await doc_list.load_more(mock_client)
+        # After loading partial batch (<50), has_more should be False
+        assert doc_list.has_more is False