prepare: warn but don't fail on initialised db (bug 1956987)

phabricatoremails/alembic/versions/3fc2902fe464_.py

@@ -9,6 +9,7 @@
 Create Date: 2020-04-09 09:57:09.401710
 
 """
+
 import sqlalchemy as sa
 from alembic import op
 

phabricatoremails/db.py

@@ -12,10 +12,6 @@
 from sqlalchemy.orm import sessionmaker
 
 
-class DBInitializedError(Exception):
-    pass
-
-
 class DBNotInitializedError(Exception):
     pass
 

phabricatoremails/prepare.py

@@ -1,7 +1,6 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
-from phabricatoremails.db import DBInitializedError
 from phabricatoremails.query_position_store import DBQueryPositionStore
 from phabricatoremails.settings import Settings
 
@@ -20,11 +19,12 @@ def prepare(settings: Settings):
     # want to invoke multiple times. This check asserts that "prepare" isn't
     # run more than one time.
     if db.is_initialized():
-        raise DBInitializedError(
+        settings.logger.warning(
             "Database has already been initialized! Run "
             "`phabricator-emails migrate` to upgrade an existing "
             "database"
         )
+        return
 
     # We fetch the end key at the beginning here so that we fail early if
     # we can't successfully communicate with Phabricator

setup.cfg

@@ -4,6 +4,7 @@
 
 [flake8]
 max-line-length = 88
+ignore = W503
 
 # [mypy] section is now required in setup.cfg due to this issue:
 # https://github.com/python/mypy/issues/9940

tests/test_prepare.py

@@ -2,23 +2,21 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-import pytest
 from kgb import spy_on
 
-from phabricatoremails.db import DBInitializedError
 from phabricatoremails.prepare import prepare
 from tests.mock_db import MockDB
 from tests.mock_settings import MockSettings
 from tests.mock_source import MockSource
 from tests.mock_worker import MockWorker
 
 
-def test_prepare_doesnt_upgrade_schema_if_already_initialized():
+def test_prepare_doesnt_upgrade_schema_if_already_initialized(caplog):
     db = MockDB(is_initialized=True)
     settings = MockSettings(db=db)
     with spy_on(db.upgrade_schema) as spy:
-        with pytest.raises(DBInitializedError):
-            prepare(settings)
+        prepare(settings)
+        assert "already been initialized!" in caplog.text
         assert not spy.called