feat(search): add whoosh-compat, the shared field table and the field registry

src/documents/tests/search/test_schema_version.py

@@ -0,0 +1,164 @@
+"""SCHEMA_VERSION must change whenever build_schema()'s field list or order does.
+
+tantivy compares schemas by *ordered* field list. ``Index.open()`` loads the
+schema from the index's own ``meta.json``, so reads against an index built by an
+older release keep working after a field reorder. Writes do not:
+``WriteBatch.__enter__`` calls ``tantivy.Index(build_schema(), path=...)``, an
+open-or-create that raises ``ValueError`` on any schema difference. Nothing
+catches that ValueError, so consumption, index_document and bulk edit all
+hard-fail while ``/api/status/`` still reports the index healthy.
+
+The only thing that saves such an install is ``needs_rebuild()`` noticing the
+version stamped in ``.index_settings.json`` is stale.
+"""
+
+from __future__ import annotations
+
+import json
+from typing import TYPE_CHECKING
+
+import pytest
+import tantivy
+from django.conf import settings as django_settings
+
+from documents.search._schema import build_schema
+from documents.search._schema import needs_rebuild
+from documents.search._schema import open_or_rebuild_index
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+pytestmark = [pytest.mark.search]
+
+RELEASED_V1_SCHEMA_VERSION = 1
+
+
+def _build_released_v1_schema() -> tantivy.Schema:
+    """Frozen copy of build_schema() as shipped in v3.0.x (schema version 1).
+
+    Deliberately duplicated rather than imported: it must keep describing the
+    on-disk layout of already-deployed indexes even as build_schema() evolves.
+    """
+    sb = tantivy.SchemaBuilder()
+
+    sb.add_unsigned_field("id", stored=True, indexed=True, fast=True)
+    sb.add_text_field("checksum", stored=True, tokenizer_name="raw")
+
+    for field in (
+        "title",
+        "correspondent",
+        "document_type",
+        "storage_path",
+        "original_filename",
+        "content",
+    ):
+        sb.add_text_field(field, stored=True, tokenizer_name="paperless_text")
+
+    for field in ("title_sort", "correspondent_sort", "type_sort"):
+        sb.add_text_field(
+            field,
+            stored=False,
+            tokenizer_name="simple_analyzer",
+            fast=True,
+        )
+
+    for field in (
+        "bigram_content",
+        "bigram_title",
+        "bigram_correspondent",
+        "bigram_document_type",
+        "bigram_tag",
+    ):
+        sb.add_text_field(field, stored=False, tokenizer_name="bigram_analyzer")
+
+    for field in ("simple_title", "simple_content"):
+        sb.add_text_field(field, stored=False, tokenizer_name="simple_search_analyzer")
+
+    sb.add_text_field("autocomplete_word", stored=False, tokenizer_name="raw")
+    sb.add_text_field("tag", stored=True, tokenizer_name="paperless_text")
+
+    sb.add_json_field("notes", stored=True, tokenizer_name="paperless_text")
+    sb.add_text_field("notes_text", stored=True, tokenizer_name="paperless_text")
+    sb.add_json_field("custom_fields", stored=True, tokenizer_name="paperless_text")
+
+    for field in (
+        "correspondent_id",
+        "document_type_id",
+        "storage_path_id",
+        "tag_id",
+        "owner_id",
+        "viewer_id",
+        "viewer_group_id",
+    ):
+        sb.add_unsigned_field(field, stored=False, indexed=True, fast=True)
+
+    for field in ("created", "modified", "added"):
+        sb.add_date_field(field, stored=True, indexed=True, fast=True)
+
+    for field in ("asn", "page_count", "num_notes"):
+        sb.add_unsigned_field(field, stored=True, indexed=True, fast=True)
+
+    return sb.build()
+
+
+@pytest.fixture
+def released_v1_index(tmp_path: Path) -> Path:
+    """An index directory as a v3.0.x install would leave it on disk."""
+    index_dir = tmp_path / "index"
+    index_dir.mkdir()
+    tantivy.Index(_build_released_v1_schema(), path=str(index_dir))
+    (index_dir / ".index_settings.json").write_text(
+        json.dumps(
+            {
+                "schema_version": RELEASED_V1_SCHEMA_VERSION,
+                "language": django_settings.SEARCH_LANGUAGE,
+            },
+        ),
+    )
+    return index_dir
+
+
+class TestUpgradeFromReleasedV1Index:
+    def test_released_v1_index_is_flagged_for_rebuild(
+        self,
+        released_v1_index: Path,
+    ) -> None:
+        """The current schema differs from v1's, so the sentinel must be stale.
+
+        If this fails, `document_index reindex --if-needed` prints "Search index
+        is up to date" and skips, leaving the mismatched index in place.
+        """
+        assert needs_rebuild(released_v1_index) is True
+
+    def test_v1_index_rejects_writes_against_the_current_schema(
+        self,
+        released_v1_index: Path,
+    ) -> None:
+        """The failure mode the version bump exists to prevent.
+
+        This is exactly what WriteBatch.__enter__ does on every index write.
+        """
+        with pytest.raises(ValueError, match="schema does not match"):
+            tantivy.Index(build_schema(), path=str(released_v1_index))
+
+    def test_opening_a_v1_index_leaves_it_writable(
+        self,
+        released_v1_index: Path,
+    ) -> None:
+        """End to end: open_or_rebuild_index must hand back an index that the
+        write path can reopen. Before the version bump, needs_rebuild() returned
+        False here, the stale directory survived untouched, and every subsequent
+        write raised the ValueError above."""
+        open_or_rebuild_index(released_v1_index)
+
+        tantivy.Index(build_schema(), path=str(released_v1_index))
+
+    def test_rebuilt_index_is_not_rebuilt_again(
+        self,
+        released_v1_index: Path,
+    ) -> None:
+        """The rebuild must stamp the version it actually wrote, otherwise every
+        startup wipes and reindexes the whole corpus."""
+        open_or_rebuild_index(released_v1_index)
+
+        assert needs_rebuild(released_v1_index) is False