feat: improved agent streaming

surfsense_backend/tests/unit/db/test_relax_revision_fks_migration.py

@@ -0,0 +1,83 @@
+"""Smoke test for the ``134_relax_revision_fks`` Alembic migration.
+
+A full apply/rollback test would require a live Postgres; here we verify
+the migration module's static contract:
+
+* The chain wires it as a successor of ``133_drop_documents_content_hash_unique``.
+* ``upgrade()`` declares two FK creations with ``ondelete='SET NULL'``
+  (one for ``document_revisions.document_id``, one for
+  ``folder_revisions.folder_id``).
+* ``downgrade()`` re-establishes ``ondelete='CASCADE'`` after draining
+  orphaned revisions.
+
+If any of these invariants regress the snapshot/revert pipeline silently
+loses the ability to undo ``rm`` / ``rmdir`` on environments that ran the
+migration "down" or never ran it at all.
+"""
+
+from __future__ import annotations
+
+import importlib.util
+import inspect
+from pathlib import Path
+
+import pytest
+
+pytestmark = pytest.mark.unit
+
+
+_MIGRATION_PATH = (
+    Path(__file__).resolve().parents[3]
+    / "alembic"
+    / "versions"
+    / "134_relax_revision_fks.py"
+)
+
+
+def _load_migration():
+    """Load the migration module by file path (no package import needed)."""
+    spec = importlib.util.spec_from_file_location("_migration_134", _MIGRATION_PATH)
+    assert spec and spec.loader, "could not load migration spec"
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+def test_migration_chain_revision_ids() -> None:
+    module = _load_migration()
+    # The migration file uses short numeric revision IDs to match the
+    # in-tree convention (cf. ``133`` -> ``134``); the ``134_<slug>.py``
+    # filename is documentation, not the canonical revision string.
+    assert getattr(module, "revision", None) == "134"
+    assert getattr(module, "down_revision", None) == "133"
+
+
+def test_migration_exposes_upgrade_and_downgrade() -> None:
+    module = _load_migration()
+    upgrade = getattr(module, "upgrade", None)
+    downgrade = getattr(module, "downgrade", None)
+    assert callable(upgrade), "upgrade() is required"
+    assert callable(downgrade), "downgrade() is required"
+
+
+def test_upgrade_creates_set_null_fks_for_both_revision_tables() -> None:
+    module = _load_migration()
+    src = inspect.getsource(module.upgrade)
+    assert "document_revisions" in src
+    assert "folder_revisions" in src
+    # Both new FKs MUST be ON DELETE SET NULL — that's the entire point
+    # of the migration: snapshots must outlive their parent row.
+    assert src.count('ondelete="SET NULL"') >= 2
+    # And the ``document_id`` / ``folder_id`` columns become nullable.
+    assert "nullable=True" in src
+
+
+def test_downgrade_drains_orphans_then_restores_cascade() -> None:
+    module = _load_migration()
+    src = inspect.getsource(module.downgrade)
+    # Drain orphaned rows BEFORE we can re-impose NOT NULL.
+    assert "DELETE FROM document_revisions WHERE document_id IS NULL" in src
+    assert "DELETE FROM folder_revisions WHERE folder_id IS NULL" in src
+    # Then restore the original CASCADE/NOT NULL contract.
+    assert src.count('ondelete="CASCADE"') >= 2
+    assert "nullable=False" in src