feat: add PageIndex SDK with local/cloud dual-mode support (#207)

tests/test_local_backend.py

@@ -0,0 +1,50 @@
+# tests/sdk/test_local_backend.py
+import pytest
+from pathlib import Path
+from pageindex.backend.local import LocalBackend
+from pageindex.storage.sqlite import SQLiteStorage
+from pageindex.errors import FileTypeError
+
+
+@pytest.fixture
+def backend(tmp_path):
+    storage = SQLiteStorage(str(tmp_path / "test.db"))
+    files_dir = tmp_path / "files"
+    return LocalBackend(storage=storage, files_dir=str(files_dir), model="gpt-4o")
+
+
+def test_collection_lifecycle(backend):
+    backend.get_or_create_collection("papers")
+    assert "papers" in backend.list_collections()
+    backend.delete_collection("papers")
+    assert "papers" not in backend.list_collections()
+
+
+def test_list_documents_empty(backend):
+    backend.get_or_create_collection("papers")
+    assert backend.list_documents("papers") == []
+
+
+def test_unsupported_file_type_raises(backend, tmp_path):
+    backend.get_or_create_collection("papers")
+    bad_file = tmp_path / "test.xyz"
+    bad_file.write_text("hello")
+    with pytest.raises(FileTypeError):
+        backend.add_document("papers", str(bad_file))
+
+
+def test_register_custom_parser(backend):
+    from pageindex.parser.protocol import ParsedDocument, ContentNode
+
+    class TxtParser:
+        def supported_extensions(self):
+            return [".txt"]
+        def parse(self, file_path, **kwargs):
+            text = Path(file_path).read_text()
+            return ParsedDocument(doc_name="test", nodes=[
+                ContentNode(content=text, tokens=len(text.split()), title="Content", index=1, level=1)
+            ])
+
+    backend.register_parser(TxtParser())
+    # Now .txt should be supported (won't raise FileTypeError)
+    assert backend._resolve_parser("test.txt") is not None