Add database migrations

- use Alembic to migrate the PostgreSQL database
  + create initial migration script to set up the database,
    as an alternative to db.Base.metadata.create_all()
  + integrate Alembic into the test suite; the db_engine fixture
    now has two modes:
    * create the latest version of tables all at once
    * invoke `alembic upgrade head`
    => the "e2e" tests are all run twice, once in each mode; this
       ensures that the migration scripts re-create the same database
       schema as db.Base.metadata.create_all() would
    * in both modes, a temporary PostgreSQL schema is used to create the
      tables in
    => could now run "e2e" tests against production database and still
       have isolation
- make the configuration module public (to be used by Alembic)
- adjust linting rules for Alembic

alembic.ini

@@ -0,0 +1,44 @@
+[alembic]
+file_template = rev_%%(year)d%%(month).2d%%(day).2d_%%(hour).2d_%%(rev)s_%%(slug)s
+script_location = %(here)s/migrations
+
+[post_write_hooks]
+hooks=black
+black.type=console_scripts
+black.entrypoint=black
+
+# The following is taken from the default alembic.ini file.
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

migrations/README.md

@@ -0,0 +1,4 @@
+# Database Migrations
+
+This project uses [alembic](https://alembic.sqlalchemy.org/en/latest)
+to run the database migrations

migrations/env.py

@@ -0,0 +1,45 @@
+"""Configure Alembic's migration environment."""
+
+import os
+from logging import config as log_config
+
+import sqlalchemy as sa
+from alembic import context
+
+from urban_meal_delivery import config as umd_config
+from urban_meal_delivery import db
+
+
+# Disable the --sql option, a.k.a, the "offline mode".
+if context.is_offline_mode():
+    raise NotImplementedError('The --sql option is not implemented in this project')
+
+
+# Set up the default Python logger from the alembic.ini file.
+log_config.fileConfig(context.config.config_file_name)
+
+
+def include_object(obj, _name, type_, _reflected, _compare_to):
+    """Only include the clean schema into --autogenerate migrations."""
+    if type_ in {'table', 'column'} and obj.schema != umd_config.DATABASE_SCHEMA:
+        return False
+
+    return True
+
+
+engine = sa.create_engine(umd_config.DATABASE_URI)
+
+with engine.connect() as connection:
+    context.configure(
+        connection=connection,
+        include_object=include_object,
+        target_metadata=db.Base.metadata,
+        version_table='{alembic_table}{test_schema}'.format(
+            alembic_table=umd_config.ALEMBIC_TABLE,
+            test_schema=(f'_{umd_config.CLEAN_SCHEMA}' if os.getenv('TESTING') else ''),
+        ),
+        version_table_schema=umd_config.ALEMBIC_TABLE_SCHEMA,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()

migrations/script.py.mako

@@ -0,0 +1,31 @@
+"""${message}.
+
+Revision: # ${up_revision} at ${create_date}
+Revises: # ${down_revision | comma,n}
+"""
+
+import os
+
+import sqlalchemy as sa
+from alembic import op
+${imports if imports else ""}
+
+from urban_meal_delivery import configuration
+
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+config = configuration.make_config('testing' if os.getenv('TESTING') else 'production')
+
+
+def upgrade():
+    """Upgrade to revision ${up_revision}."""
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    """Downgrade to revision ${down_revision}."""
+    ${downgrades if downgrades else "pass"}

migrations/versions/rev_20200806_23_f11cd76d2f45_create_the_database.py

@@ -0,0 +1,802 @@
+"""Create the database from scratch.
+
+Revision: #f11cd76d2f45 at 2020-08-06 23:24:32
+"""
+
+import os
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+from urban_meal_delivery import configuration
+
+
+revision = 'f11cd76d2f45'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+config = configuration.make_config('testing' if os.getenv('TESTING') else 'production')
+
+
+def upgrade():
+    """Upgrade to revision f11cd76d2f45."""
+    op.execute(f'CREATE SCHEMA {config.CLEAN_SCHEMA};')
+    op.create_table(  # noqa:ECE001
+        'cities',
+        sa.Column('id', sa.SmallInteger(), autoincrement=False, nullable=False),
+        sa.Column('name', sa.Unicode(length=10), nullable=False),
+        sa.Column('kml', sa.UnicodeText(), nullable=False),
+        sa.Column('center_latitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('center_longitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('northeast_latitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('northeast_longitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('southwest_latitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('southwest_longitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('initial_zoom', sa.SmallInteger(), nullable=False),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_cities')),
+        *(
+            [  # noqa:WPS504
+                sa.ForeignKeyConstraint(
+                    ['id'],
+                    [f'{config.ORIGINAL_SCHEMA}.cities.id'],
+                    name=op.f('pk_cities_sanity'),
+                    onupdate='RESTRICT',
+                    ondelete='RESTRICT',
+                ),
+            ]
+            if not config.TESTING
+            else []
+        ),
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_table(  # noqa:ECE001
+        'couriers',
+        sa.Column('id', sa.Integer(), autoincrement=False, nullable=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('vehicle', sa.Unicode(length=10), nullable=False),
+        sa.Column('speed', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('capacity', sa.SmallInteger(), nullable=False),
+        sa.Column('pay_per_hour', sa.SmallInteger(), nullable=False),
+        sa.Column('pay_per_order', sa.SmallInteger(), nullable=False),
+        sa.CheckConstraint(
+            "vehicle IN ('bicycle', 'motorcycle')",
+            name=op.f('ck_couriers_on_available_vehicle_types'),
+        ),
+        sa.CheckConstraint(
+            '0 <= capacity AND capacity <= 200',
+            name=op.f('ck_couriers_on_capacity_under_200_liters'),
+        ),
+        sa.CheckConstraint(
+            '0 <= pay_per_hour AND pay_per_hour <= 1500',
+            name=op.f('ck_couriers_on_realistic_pay_per_hour'),
+        ),
+        sa.CheckConstraint(
+            '0 <= pay_per_order AND pay_per_order <= 650',
+            name=op.f('ck_couriers_on_realistic_pay_per_order'),
+        ),
+        sa.CheckConstraint(
+            '0 <= speed AND speed <= 30', name=op.f('ck_couriers_on_realistic_speed'),
+        ),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_couriers')),
+        *(
+            [  # noqa:WPS504
+                sa.ForeignKeyConstraint(
+                    ['id'],
+                    [f'{config.ORIGINAL_SCHEMA}.couriers.id'],
+                    name=op.f('pk_couriers_sanity'),
+                    onupdate='RESTRICT',
+                    ondelete='RESTRICT',
+                ),
+            ]
+            if not config.TESTING
+            else []
+        ),
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_table(
+        'customers',
+        sa.Column('id', sa.Integer(), autoincrement=False, nullable=False),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_customers')),
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_table(  # noqa:ECE001
+        'addresses',
+        sa.Column('id', sa.Integer(), autoincrement=False, nullable=False),
+        sa.Column('primary_id', sa.Integer(), nullable=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('place_id', sa.Unicode(length=120), nullable=False),  # noqa:WPS432
+        sa.Column('latitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('longitude', postgresql.DOUBLE_PRECISION(), nullable=False),
+        sa.Column('city_id', sa.SmallInteger(), nullable=False),
+        sa.Column('city', sa.Unicode(length=25), nullable=False),  # noqa:WPS432
+        sa.Column('zip_code', sa.Integer(), nullable=False),
+        sa.Column('street', sa.Unicode(length=80), nullable=False),  # noqa:WPS432
+        sa.Column('floor', sa.SmallInteger(), nullable=True),
+        sa.CheckConstraint(
+            '-180 <= longitude AND longitude <= 180',
+            name=op.f('ck_addresses_on_longitude_between_180_degrees'),
+        ),
+        sa.CheckConstraint(
+            '-90 <= latitude AND latitude <= 90',
+            name=op.f('ck_addresses_on_latitude_between_90_degrees'),
+        ),
+        sa.CheckConstraint(
+            '0 <= floor AND floor <= 40', name=op.f('ck_addresses_on_realistic_floor'),
+        ),
+        sa.CheckConstraint(
+            '30000 <= zip_code AND zip_code <= 99999',
+            name=op.f('ck_addresses_on_valid_zip_code'),
+        ),
+        sa.ForeignKeyConstraint(
+            ['city_id'],
+            [f'{config.CLEAN_SCHEMA}.cities.id'],
+            name=op.f('fk_addresses_to_cities_via_city_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.ForeignKeyConstraint(
+            ['primary_id'],
+            [f'{config.CLEAN_SCHEMA}.addresses.id'],
+            name=op.f('fk_addresses_to_addresses_via_primary_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_addresses')),
+        *(
+            [  # noqa:WPS504
+                sa.ForeignKeyConstraint(
+                    ['id'],
+                    [f'{config.ORIGINAL_SCHEMA}.addresses.id'],
+                    name=op.f('pk_addresses_sanity'),
+                    onupdate='RESTRICT',
+                    ondelete='RESTRICT',
+                ),
+            ]
+            if not config.TESTING
+            else []
+        ),
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_addresses_on_city_id'),
+        'addresses',
+        ['city_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_addresses_on_place_id'),
+        'addresses',
+        ['place_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_addresses_on_primary_id'),
+        'addresses',
+        ['primary_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_addresses_on_zip_code'),
+        'addresses',
+        ['zip_code'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_table(  # noqa:ECE001
+        'restaurants',
+        sa.Column('id', sa.SmallInteger(), autoincrement=False, nullable=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('name', sa.Unicode(length=45), nullable=False),  # noqa:WPS432
+        sa.Column('address_id', sa.Integer(), nullable=False),
+        sa.Column('estimated_prep_duration', sa.SmallInteger(), nullable=False),
+        sa.CheckConstraint(
+            '0 <= estimated_prep_duration AND estimated_prep_duration <= 2400',
+            name=op.f('ck_restaurants_on_realistic_estimated_prep_duration'),
+        ),
+        sa.ForeignKeyConstraint(
+            ['address_id'],
+            [f'{config.CLEAN_SCHEMA}.addresses.id'],
+            name=op.f('fk_restaurants_to_addresses_via_address_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_restaurants')),
+        *(
+            [  # noqa:WPS504
+                sa.ForeignKeyConstraint(
+                    ['id'],
+                    [f'{config.ORIGINAL_SCHEMA}.businesses.id'],
+                    name=op.f('pk_restaurants_sanity'),
+                    onupdate='RESTRICT',
+                    ondelete='RESTRICT',
+                ),
+            ]
+            if not config.TESTING
+            else []
+        ),
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_restaurants_on_address_id'),
+        'restaurants',
+        ['address_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_table(  # noqa:ECE001
+        'orders',
+        sa.Column('id', sa.Integer(), autoincrement=False, nullable=False),
+        sa.Column('delivery_id', sa.Integer(), nullable=True),
+        sa.Column('customer_id', sa.Integer(), nullable=False),
+        sa.Column('placed_at', sa.DateTime(), nullable=False),
+        sa.Column('ad_hoc', sa.Boolean(), nullable=False),
+        sa.Column('scheduled_delivery_at', sa.DateTime(), nullable=True),
+        sa.Column('scheduled_delivery_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('first_estimated_delivery_at', sa.DateTime(), nullable=True),
+        sa.Column('cancelled', sa.Boolean(), nullable=False),
+        sa.Column('cancelled_at', sa.DateTime(), nullable=True),
+        sa.Column('cancelled_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('sub_total', sa.Integer(), nullable=False),
+        sa.Column('delivery_fee', sa.SmallInteger(), nullable=False),
+        sa.Column('total', sa.Integer(), nullable=False),
+        sa.Column('restaurant_id', sa.SmallInteger(), nullable=False),
+        sa.Column('restaurant_notified_at', sa.DateTime(), nullable=True),
+        sa.Column('restaurant_notified_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('restaurant_confirmed_at', sa.DateTime(), nullable=True),
+        sa.Column('restaurant_confirmed_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('estimated_prep_duration', sa.Integer(), nullable=True),
+        sa.Column('estimated_prep_duration_corrected', sa.Boolean(), nullable=True),
+        sa.Column('estimated_prep_buffer', sa.Integer(), nullable=False),
+        sa.Column('courier_id', sa.Integer(), nullable=True),
+        sa.Column('dispatch_at', sa.DateTime(), nullable=True),
+        sa.Column('dispatch_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('courier_notified_at', sa.DateTime(), nullable=True),
+        sa.Column('courier_notified_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('courier_accepted_at', sa.DateTime(), nullable=True),
+        sa.Column('courier_accepted_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('utilization', sa.SmallInteger(), nullable=False),
+        sa.Column('pickup_address_id', sa.Integer(), nullable=False),
+        sa.Column('reached_pickup_at', sa.DateTime(), nullable=True),
+        sa.Column('pickup_at', sa.DateTime(), nullable=True),
+        sa.Column('pickup_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('pickup_not_confirmed', sa.Boolean(), nullable=True),
+        sa.Column('left_pickup_at', sa.DateTime(), nullable=True),
+        sa.Column('left_pickup_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('delivery_address_id', sa.Integer(), nullable=False),
+        sa.Column('reached_delivery_at', sa.DateTime(), nullable=True),
+        sa.Column('delivery_at', sa.DateTime(), nullable=True),
+        sa.Column('delivery_at_corrected', sa.Boolean(), nullable=True),
+        sa.Column('delivery_not_confirmed', sa.Boolean(), nullable=True),
+        sa.Column('courier_waited_at_delivery', sa.Boolean(), nullable=True),
+        sa.Column('logged_delivery_distance', sa.SmallInteger(), nullable=True),
+        sa.Column('logged_avg_speed', postgresql.DOUBLE_PRECISION(), nullable=True),
+        sa.Column('logged_avg_speed_distance', sa.SmallInteger(), nullable=True),
+        sa.CheckConstraint(
+            '0 <= estimated_prep_buffer AND estimated_prep_buffer <= 900',
+            name=op.f('ck_orders_on_estimated_prep_buffer_between_0_and_900'),
+        ),
+        sa.CheckConstraint(
+            '0 <= estimated_prep_duration AND estimated_prep_duration <= 2700',
+            name=op.f('ck_orders_on_estimated_prep_duration_between_0_and_2700'),
+        ),
+        sa.CheckConstraint(
+            '0 <= utilization AND utilization <= 100',
+            name=op.f('ck_orders_on_utilization_between_0_and_100'),
+        ),
+        sa.CheckConstraint(
+            '(cancelled_at IS NULL AND cancelled_at_corrected IS NULL) OR (cancelled_at IS NULL AND cancelled_at_corrected IS TRUE) OR (cancelled_at IS NOT NULL AND cancelled_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_1'),
+        ),
+        sa.CheckConstraint(
+            '(courier_accepted_at IS NULL AND courier_accepted_at_corrected IS NULL) OR (courier_accepted_at IS NULL AND courier_accepted_at_corrected IS TRUE) OR (courier_accepted_at IS NOT NULL AND courier_accepted_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_7'),
+        ),
+        sa.CheckConstraint(
+            '(courier_notified_at IS NULL AND courier_notified_at_corrected IS NULL) OR (courier_notified_at IS NULL AND courier_notified_at_corrected IS TRUE) OR (courier_notified_at IS NOT NULL AND courier_notified_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_6'),
+        ),
+        sa.CheckConstraint(
+            '(delivery_at IS NULL AND delivery_at_corrected IS NULL) OR (delivery_at IS NULL AND delivery_at_corrected IS TRUE) OR (delivery_at IS NOT NULL AND delivery_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_10'),
+        ),
+        sa.CheckConstraint(
+            '(dispatch_at IS NULL AND dispatch_at_corrected IS NULL) OR (dispatch_at IS NULL AND dispatch_at_corrected IS TRUE) OR (dispatch_at IS NOT NULL AND dispatch_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_5'),
+        ),
+        sa.CheckConstraint(
+            '(estimated_prep_duration IS NULL AND estimated_prep_duration_corrected IS NULL) OR (estimated_prep_duration IS NULL AND estimated_prep_duration_corrected IS TRUE) OR (estimated_prep_duration IS NOT NULL AND estimated_prep_duration_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_4'),
+        ),
+        sa.CheckConstraint(
+            '(left_pickup_at IS NULL AND left_pickup_at_corrected IS NULL) OR (left_pickup_at IS NULL AND left_pickup_at_corrected IS TRUE) OR (left_pickup_at IS NOT NULL AND left_pickup_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_9'),
+        ),
+        sa.CheckConstraint(
+            '(pickup_at IS NULL AND pickup_at_corrected IS NULL) OR (pickup_at IS NULL AND pickup_at_corrected IS TRUE) OR (pickup_at IS NOT NULL AND pickup_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_8'),
+        ),
+        sa.CheckConstraint(
+            '(restaurant_confirmed_at IS NULL AND restaurant_confirmed_at_corrected IS NULL) OR (restaurant_confirmed_at IS NULL AND restaurant_confirmed_at_corrected IS TRUE) OR (restaurant_confirmed_at IS NOT NULL AND restaurant_confirmed_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_3'),
+        ),
+        sa.CheckConstraint(
+            '(restaurant_notified_at IS NULL AND restaurant_notified_at_corrected IS NULL) OR (restaurant_notified_at IS NULL AND restaurant_notified_at_corrected IS TRUE) OR (restaurant_notified_at IS NOT NULL AND restaurant_notified_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_2'),
+        ),
+        sa.CheckConstraint(
+            '(scheduled_delivery_at IS NULL AND scheduled_delivery_at_corrected IS NULL) OR (scheduled_delivery_at IS NULL AND scheduled_delivery_at_corrected IS TRUE) OR (scheduled_delivery_at IS NOT NULL AND scheduled_delivery_at_corrected IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_corrections_only_for_set_value_0'),
+        ),
+        sa.CheckConstraint(
+            '(ad_hoc IS TRUE AND scheduled_delivery_at IS NULL) OR (ad_hoc IS FALSE AND scheduled_delivery_at IS NOT NULL)',  # noqa:E501
+            name=op.f('ck_orders_on_either_ad_hoc_or_scheduled_order'),
+        ),
+        sa.CheckConstraint(
+            'NOT (EXTRACT(EPOCH FROM scheduled_delivery_at - placed_at) < 1800)',
+            name=op.f('ck_orders_on_scheduled_orders_not_within_30_minutes'),
+        ),
+        sa.CheckConstraint(
+            'NOT (ad_hoc IS FALSE AND ((EXTRACT(HOUR FROM scheduled_delivery_at) <= 11 AND NOT (EXTRACT(HOUR FROM scheduled_delivery_at) = 11 AND EXTRACT(MINUTE FROM scheduled_delivery_at) = 45)) OR EXTRACT(HOUR FROM scheduled_delivery_at) > 22))',  # noqa:E501
+            name=op.f('ck_orders_on_scheduled_orders_within_business_hours'),
+        ),
+        sa.CheckConstraint(
+            'NOT (ad_hoc IS TRUE AND (EXTRACT(HOUR FROM placed_at) < 11 OR EXTRACT(HOUR FROM placed_at) > 22))',  # noqa:E501
+            name=op.f('ck_orders_on_ad_hoc_orders_within_business_hours'),
+        ),
+        sa.CheckConstraint(
+            'NOT (cancelled IS FALSE AND cancelled_at IS NOT NULL)',
+            name=op.f('ck_orders_on_only_cancelled_orders_may_have_cancelled_at'),
+        ),
+        sa.CheckConstraint(
+            'NOT (cancelled IS TRUE AND delivery_at IS NOT NULL)',
+            name=op.f('ck_orders_on_cancelled_orders_must_not_be_delivered'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > courier_accepted_at',
+            name=op.f('ck_orders_on_ordered_timestamps_16'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > courier_notified_at',
+            name=op.f('ck_orders_on_ordered_timestamps_15'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_21'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > dispatch_at',
+            name=op.f('ck_orders_on_ordered_timestamps_14'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_19'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > pickup_at', name=op.f('ck_orders_on_ordered_timestamps_18'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_20'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > reached_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_17'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > restaurant_confirmed_at',
+            name=op.f('ck_orders_on_ordered_timestamps_13'),
+        ),
+        sa.CheckConstraint(
+            'cancelled_at > restaurant_notified_at',
+            name=op.f('ck_orders_on_ordered_timestamps_12'),
+        ),
+        sa.CheckConstraint(
+            'courier_accepted_at < delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_42'),
+        ),
+        sa.CheckConstraint(
+            'courier_accepted_at < left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_40'),
+        ),
+        sa.CheckConstraint(
+            'courier_accepted_at < pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_39'),
+        ),
+        sa.CheckConstraint(
+            'courier_accepted_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_41'),
+        ),
+        sa.CheckConstraint(
+            'courier_accepted_at < reached_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_38'),
+        ),
+        sa.CheckConstraint(
+            'courier_notified_at < courier_accepted_at',
+            name=op.f('ck_orders_on_ordered_timestamps_32'),
+        ),
+        sa.CheckConstraint(
+            'courier_notified_at < delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_37'),
+        ),
+        sa.CheckConstraint(
+            'courier_notified_at < left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_35'),
+        ),
+        sa.CheckConstraint(
+            'courier_notified_at < pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_34'),
+        ),
+        sa.CheckConstraint(
+            'courier_notified_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_36'),
+        ),
+        sa.CheckConstraint(
+            'courier_notified_at < reached_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_33'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < courier_accepted_at',
+            name=op.f('ck_orders_on_ordered_timestamps_26'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < courier_notified_at',
+            name=op.f('ck_orders_on_ordered_timestamps_25'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_31'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_29'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < pickup_at', name=op.f('ck_orders_on_ordered_timestamps_28'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_30'),
+        ),
+        sa.CheckConstraint(
+            'dispatch_at < reached_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_27'),
+        ),
+        sa.CheckConstraint(
+            'estimated_prep_buffer % 60 = 0',
+            name=op.f('ck_orders_on_estimated_prep_buffer_must_be_whole_minutes'),
+        ),
+        sa.CheckConstraint(
+            'estimated_prep_duration % 60 = 0',
+            name=op.f('ck_orders_on_estimated_prep_duration_must_be_whole_minutes'),
+        ),
+        sa.CheckConstraint(
+            'left_pickup_at < delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_51'),
+        ),
+        sa.CheckConstraint(
+            'left_pickup_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_50'),
+        ),
+        sa.CheckConstraint(
+            'pickup_at < delivery_at', name=op.f('ck_orders_on_ordered_timestamps_49'),
+        ),
+        sa.CheckConstraint(
+            'pickup_at < left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_47'),
+        ),
+        sa.CheckConstraint(
+            'pickup_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_48'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < cancelled_at', name=op.f('ck_orders_on_ordered_timestamps_2'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < courier_accepted_at',
+            name=op.f('ck_orders_on_ordered_timestamps_7'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < courier_notified_at',
+            name=op.f('ck_orders_on_ordered_timestamps_6'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < delivery_at', name=op.f('ck_orders_on_ordered_timestamps_11'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < dispatch_at', name=op.f('ck_orders_on_ordered_timestamps_5'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < first_estimated_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_1'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_9'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_10'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < reached_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_8'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < restaurant_confirmed_at',
+            name=op.f('ck_orders_on_ordered_timestamps_4'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < restaurant_notified_at',
+            name=op.f('ck_orders_on_ordered_timestamps_3'),
+        ),
+        sa.CheckConstraint(
+            'placed_at < scheduled_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_0'),
+        ),
+        sa.CheckConstraint(
+            'reached_delivery_at < delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_52'),
+        ),
+        sa.CheckConstraint(
+            'reached_pickup_at < delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_46'),
+        ),
+        sa.CheckConstraint(
+            'reached_pickup_at < left_pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_44'),
+        ),
+        sa.CheckConstraint(
+            'reached_pickup_at < pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_43'),
+        ),
+        sa.CheckConstraint(
+            'reached_pickup_at < reached_delivery_at',
+            name=op.f('ck_orders_on_ordered_timestamps_45'),
+        ),
+        sa.CheckConstraint(
+            'restaurant_confirmed_at < pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_24'),
+        ),
+        sa.CheckConstraint(
+            'restaurant_notified_at < pickup_at',
+            name=op.f('ck_orders_on_ordered_timestamps_23'),
+        ),
+        sa.CheckConstraint(
+            'restaurant_notified_at < restaurant_confirmed_at',
+            name=op.f('ck_orders_on_ordered_timestamps_22'),
+        ),
+        sa.CheckConstraint(
+            '(pickup_at IS NULL AND pickup_not_confirmed IS NULL) OR (pickup_at IS NOT NULL AND pickup_not_confirmed IS NOT NULL)',  # noqa:E501
+            name=op.f('pickup_not_confirmed_only_if_pickup'),
+        ),
+        sa.CheckConstraint(
+            '(delivery_at IS NULL AND delivery_not_confirmed IS NULL) OR (delivery_at IS NOT NULL AND delivery_not_confirmed IS NOT NULL)',  # noqa:E501
+            name=op.f('delivery_not_confirmed_only_if_delivery'),
+        ),
+        sa.CheckConstraint(
+            '(delivery_at IS NULL AND courier_waited_at_delivery IS NULL) OR (delivery_at IS NOT NULL AND courier_waited_at_delivery IS NOT NULL)',  # noqa:E501
+            name=op.f('courier_waited_at_delivery_only_if_delivery'),
+        ),
+        sa.ForeignKeyConstraint(
+            ['courier_id'],
+            [f'{config.CLEAN_SCHEMA}.couriers.id'],
+            name=op.f('fk_orders_to_couriers_via_courier_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.ForeignKeyConstraint(
+            ['customer_id'],
+            [f'{config.CLEAN_SCHEMA}.customers.id'],
+            name=op.f('fk_orders_to_customers_via_customer_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.ForeignKeyConstraint(
+            ['delivery_address_id'],
+            [f'{config.CLEAN_SCHEMA}.addresses.id'],
+            name=op.f('fk_orders_to_addresses_via_delivery_address_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.ForeignKeyConstraint(
+            ['pickup_address_id'],
+            [f'{config.CLEAN_SCHEMA}.addresses.id'],
+            name=op.f('fk_orders_to_addresses_via_pickup_address_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.ForeignKeyConstraint(
+            ['restaurant_id'],
+            [f'{config.CLEAN_SCHEMA}.restaurants.id'],
+            name=op.f('fk_orders_to_restaurants_via_restaurant_id'),
+            onupdate='RESTRICT',
+            ondelete='RESTRICT',
+        ),
+        sa.PrimaryKeyConstraint('id', name=op.f('pk_orders')),
+        *(
+            [  # noqa:WPS504
+                sa.ForeignKeyConstraint(
+                    ['id'],
+                    [f'{config.ORIGINAL_SCHEMA}.orders.id'],
+                    name=op.f('pk_orders_sanity'),
+                    onupdate='RESTRICT',
+                    ondelete='RESTRICT',
+                ),
+                sa.ForeignKeyConstraint(
+                    ['delivery_id'],
+                    [f'{config.ORIGINAL_SCHEMA}.deliveries.id'],
+                    name=op.f('pk_deliveries_sanity'),
+                    onupdate='RESTRICT',
+                    ondelete='RESTRICT',
+                ),
+            ]
+            if not config.TESTING
+            else []
+        ),
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_cancelled'),
+        'orders',
+        ['cancelled'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_cancelled_at_corrected'),
+        'orders',
+        ['cancelled_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_courier_accepted_at_corrected'),
+        'orders',
+        ['courier_accepted_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_courier_id'),
+        'orders',
+        ['courier_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_courier_notified_at_corrected'),
+        'orders',
+        ['courier_notified_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_customer_id'),
+        'orders',
+        ['customer_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_delivery_address_id'),
+        'orders',
+        ['delivery_address_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_delivery_at_corrected'),
+        'orders',
+        ['delivery_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_delivery_id'),
+        'orders',
+        ['delivery_id'],
+        unique=True,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_dispatch_at_corrected'),
+        'orders',
+        ['dispatch_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_estimated_prep_buffer'),
+        'orders',
+        ['estimated_prep_buffer'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_estimated_prep_duration'),
+        'orders',
+        ['estimated_prep_duration'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_estimated_prep_duration_corrected'),
+        'orders',
+        ['estimated_prep_duration_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_left_pickup_at_corrected'),
+        'orders',
+        ['left_pickup_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_pickup_address_id'),
+        'orders',
+        ['pickup_address_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_pickup_at_corrected'),
+        'orders',
+        ['pickup_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_placed_at'),
+        'orders',
+        ['placed_at'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_restaurant_confirmed_at_corrected'),
+        'orders',
+        ['restaurant_confirmed_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_restaurant_id'),
+        'orders',
+        ['restaurant_id'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_restaurant_notified_at_corrected'),
+        'orders',
+        ['restaurant_notified_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_scheduled_delivery_at'),
+        'orders',
+        ['scheduled_delivery_at'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+    op.create_index(
+        op.f('ix_orders_on_scheduled_delivery_at_corrected'),
+        'orders',
+        ['scheduled_delivery_at_corrected'],
+        unique=False,
+        schema=config.CLEAN_SCHEMA,
+    )
+
+
+def downgrade():
+    """Downgrade to revision None."""
+    op.execute(f'DROP SCHEMA {config.CLEAN_SCHEMA} CASCADE;')

noxfile.py

@@ -74,7 +74,9 @@ PYTEST_LOCATION = 'tests/'
 
 # Paths with all *.py files.
 SRC_LOCATIONS = (
-    f'{DOCS_SRC}/conf.py',
+    f'{DOCS_SRC}conf.py',
+    'migrations/env.py',
+    'migrations/versions/',
     'noxfile.py',
     PACKAGE_SOURCE_LOCATION,
     PYTEST_LOCATION,
@@ -235,7 +237,12 @@ def test(session):
     # non-develop dependencies be installed in the virtual environment.
     session.run('poetry', 'install', '--no-dev', external=True)
     _install_packages(
-        session, 'packaging', 'pytest', 'pytest-cov', 'xdoctest[optional]',
+        session,
+        'packaging',
+        'pytest',
+        'pytest-cov',
+        'pytest-env',
+        'xdoctest[optional]',
     )
 
     # Interpret extra arguments as options for pytest.

poetry.lock

@@ -6,6 +6,20 @@ optional = false
 python-versions = "*"
 version = "0.7.12"
 
+[[package]]
+category = "main"
+description = "A database migration tool for SQLAlchemy."
+name = "alembic"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+version = "1.4.2"
+
+[package.dependencies]
+Mako = "*"
+SQLAlchemy = ">=1.1.0"
+python-dateutil = "*"
+python-editor = ">=0.3"
+
 [[package]]
 category = "dev"
 description = "A small Python module for determining appropriate platform-specific dirs, e.g. a \"user data dir\"."
@@ -562,7 +576,22 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 version = "1.4.3"
 
 [[package]]
-category = "dev"
+category = "main"
+description = "A super-fast templating language that borrows the  best ideas from the existing templating languages."
+name = "mako"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+version = "1.1.3"
+
+[package.dependencies]
+MarkupSafe = ">=0.9.2"
+
+[package.extras]
+babel = ["babel"]
+lingua = ["lingua"]
+
+[[package]]
+category = "main"
 description = "Safely add untrusted strings to HTML/XML markup."
 name = "markupsafe"
 optional = false
@@ -812,6 +841,28 @@ pytest = ">=4.6"
 [package.extras]
 testing = ["fields", "hunter", "process-tests (2.0.2)", "six", "pytest-xdist", "virtualenv"]
 
+[[package]]
+category = "dev"
+description = "py.test plugin that allows you to add environment variables."
+name = "pytest-env"
+optional = false
+python-versions = "*"
+version = "0.6.2"
+
+[package.dependencies]
+pytest = ">=2.6.0"
+
+[[package]]
+category = "main"
+description = "Extensions to the standard Python datetime module"
+name = "python-dateutil"
+optional = false
+python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,>=2.7"
+version = "2.8.1"
+
+[package.dependencies]
+six = ">=1.5"
+
 [[package]]
 category = "main"
 description = "Add .env support to your django/flask apps in development and deployments"
@@ -823,6 +874,14 @@ version = "0.14.0"
 [package.extras]
 cli = ["click (>=5.0)"]
 
+[[package]]
+category = "main"
+description = "Programmatically open an editor, capture the result."
+name = "python-editor"
+optional = false
+python-versions = "*"
+version = "1.0.4"
+
 [[package]]
 category = "dev"
 description = "World timezone definitions, modern and historical"
@@ -877,7 +936,7 @@ version = "1.3.1"
 docutils = ">=0.11,<1.0"
 
 [[package]]
-category = "dev"
+category = "main"
 description = "Python 2 and 3 compatibility utilities"
 name = "six"
 optional = false
@@ -1179,7 +1238,7 @@ optional = ["pygments", "colorama"]
 tests = ["pytest", "pytest-cov", "codecov", "scikit-build", "cmake", "ninja", "pybind11"]
 
 [metadata]
-content-hash = "508cbaa3105e47cac64c68663ed8d4178ee752bf267cb24cf68264e73325e10b"
+content-hash = "3227fd9a5706b1483adc9b6cb7350515ffda05c38ab9c9a83d63594b3f4f6673"
 lock-version = "1.0"
 python-versions = "^3.8"
 
@@ -1188,6 +1247,9 @@ alabaster = [
     {file = "alabaster-0.7.12-py2.py3-none-any.whl", hash = "sha256:446438bdcca0e05bd45ea2de1668c1d9b032e1a9154c2c259092d77031ddd359"},
     {file = "alabaster-0.7.12.tar.gz", hash = "sha256:a661d72d58e6ea8a57f7a86e37d86716863ee5e92788398526d58b26a4e4dc02"},
 ]
+alembic = [
+    {file = "alembic-1.4.2.tar.gz", hash = "sha256:035ab00497217628bf5d0be82d664d8713ab13d37b630084da8e1f98facf4dbf"},
+]
 appdirs = [
     {file = "appdirs-1.4.4-py2.py3-none-any.whl", hash = "sha256:a841dacd6b99318a741b166adb07e19ee71a274450e68237b4650ca1055ab128"},
     {file = "appdirs-1.4.4.tar.gz", hash = "sha256:7d5d0167b2b1ba821647616af46a749d1c653740dd0d2415100fe26e27afdf41"},
@@ -1435,6 +1497,10 @@ lazy-object-proxy = [
     {file = "lazy_object_proxy-1.4.3-cp38-cp38-win32.whl", hash = "sha256:5541cada25cd173702dbd99f8e22434105456314462326f06dba3e180f203dfd"},
     {file = "lazy_object_proxy-1.4.3-cp38-cp38-win_amd64.whl", hash = "sha256:59f79fef100b09564bc2df42ea2d8d21a64fdcda64979c0fa3db7bdaabaf6239"},
 ]
+mako = [
+    {file = "Mako-1.1.3-py2.py3-none-any.whl", hash = "sha256:93729a258e4ff0747c876bd9e20df1b9758028946e976324ccd2d68245c7b6a9"},
+    {file = "Mako-1.1.3.tar.gz", hash = "sha256:8195c8c1400ceb53496064314c6736719c6f25e7479cd24c77be3d9361cddc27"},
+]
 markupsafe = [
     {file = "MarkupSafe-1.1.1-cp27-cp27m-macosx_10_6_intel.whl", hash = "sha256:09027a7803a62ca78792ad89403b1b7a73a01c8cb65909cd876f7fcebd79b161"},
     {file = "MarkupSafe-1.1.1-cp27-cp27m-manylinux1_i686.whl", hash = "sha256:e249096428b3ae81b08327a63a485ad0878de3fb939049038579ac0ef61e17e7"},
@@ -1580,10 +1646,24 @@ pytest-cov = [
     {file = "pytest-cov-2.10.0.tar.gz", hash = "sha256:1a629dc9f48e53512fcbfda6b07de490c374b0c83c55ff7a1720b3fccff0ac87"},
     {file = "pytest_cov-2.10.0-py2.py3-none-any.whl", hash = "sha256:6e6d18092dce6fad667cd7020deed816f858ad3b49d5b5e2b1cc1c97a4dba65c"},
 ]
+pytest-env = [
+    {file = "pytest-env-0.6.2.tar.gz", hash = "sha256:7e94956aef7f2764f3c147d216ce066bf6c42948bb9e293169b1b1c880a580c2"},
+]
+python-dateutil = [
+    {file = "python-dateutil-2.8.1.tar.gz", hash = "sha256:73ebfe9dbf22e832286dafa60473e4cd239f8592f699aa5adaf10050e6e1823c"},
+    {file = "python_dateutil-2.8.1-py2.py3-none-any.whl", hash = "sha256:75bb3f31ea686f1197762692a9ee6a7550b59fc6ca3a1f4b5d7e32fb98e2da2a"},
+]
 python-dotenv = [
     {file = "python-dotenv-0.14.0.tar.gz", hash = "sha256:8c10c99a1b25d9a68058a1ad6f90381a62ba68230ca93966882a4dbc3bc9c33d"},
     {file = "python_dotenv-0.14.0-py2.py3-none-any.whl", hash = "sha256:c10863aee750ad720f4f43436565e4c1698798d763b63234fb5021b6c616e423"},
 ]
+python-editor = [
+    {file = "python-editor-1.0.4.tar.gz", hash = "sha256:51fda6bcc5ddbbb7063b2af7509e43bd84bfc32a4ff71349ec7847713882327b"},
+    {file = "python_editor-1.0.4-py2-none-any.whl", hash = "sha256:5f98b069316ea1c2ed3f67e7f5df6c0d8f10b689964a4a811ff64f0106819ec8"},
+    {file = "python_editor-1.0.4-py2.7.egg", hash = "sha256:ea87e17f6ec459e780e4221f295411462e0d0810858e055fc514684350a2f522"},
+    {file = "python_editor-1.0.4-py3-none-any.whl", hash = "sha256:1bf6e860a8ad52a14c3ee1252d5dc25b2030618ed80c022598f00176adc8367d"},
+    {file = "python_editor-1.0.4-py3.5.egg", hash = "sha256:c3da2053dbab6b29c94e43c486ff67206eafbe7eb52dbec7390b5e2fb05aac77"},
+]
 pytz = [
     {file = "pytz-2020.1-py2.py3-none-any.whl", hash = "sha256:a494d53b6d39c3c6e44c3bec237336e14305e4f29bbf800b599253057fbb79ed"},
     {file = "pytz-2020.1.tar.gz", hash = "sha256:c35965d010ce31b23eeb663ed3cc8c906275d6be1a34393a1d73a41febf4a048"},

pyproject.toml

@@ -27,6 +27,7 @@ repository = "https://github.com/webartifex/urban-meal-delivery"
 [tool.poetry.dependencies]
 python = "^3.8"
 
+alembic = "^1.4.2"
 click = "^7.1.2"
 psycopg2 = "^2.8.5"  # adapter for PostgreSQL
 python-dotenv = "^0.14.0"
@@ -56,6 +57,7 @@ wemake-python-styleguide = "^0.14.1"  # flake8 plug-in
 packaging = "^20.4"  # used to test the packaged version
 pytest = "^6.0.1"
 pytest-cov = "^2.10.0"
+pytest-env = "^0.6.2"
 xdoctest = { version="^0.13.0", extras=["optional"] }
 
 # Documentation

setup.cfg

@@ -102,6 +102,20 @@ per-file-ignores =
     docs/conf.py:
         # Allow shadowing built-ins and reading __*__ variables.
         WPS125,WPS609,
+    migrations/env.py:
+        # Type annotations are not strictly enforced.
+        ANN0, ANN2,
+    migrations/versions/*.py:
+        # Type annotations are not strictly enforced.
+        ANN0, ANN2,
+        # File names of revisions are ok.
+        WPS114,WPS118,
+        # Revisions may have too many expressions.
+        WPS204,WPS213,
+        # No overuse of string constants (e.g., 'RESTRICT').
+        WPS226,
+        # Too many noqa's are ok.
+        WPS402,
     noxfile.py:
         # Type annotations are not strictly enforced.
         ANN0, ANN2,
@@ -111,7 +125,7 @@ per-file-ignores =
         WPS213,
         # No overuse of string constants (e.g., '--version').
         WPS226,
-    src/urban_meal_delivery/_config.py:
+    src/urban_meal_delivery/configuration.py:
         # Allow upper case class variables within classes.
         WPS115,
         # Numbers are normal in config files.
@@ -255,5 +269,7 @@ addopts =
     --strict-markers
 cache_dir = .cache/pytest
 console_output_style = count
+env =
+    TESTING=true
 markers =
     e2e: integration tests, inlc., for example, tests touching a database

src/urban_meal_delivery/__init__.py

@@ -9,7 +9,7 @@ Example:
 import os as _os
 from importlib import metadata as _metadata
 
-from urban_meal_delivery import _config  # noqa:WPS450
+from urban_meal_delivery import configuration as _configuration
 
 
 try:
@@ -26,8 +26,8 @@ else:
     __version__ = _pkg_info['version']
 
 
-# Little Hack: "Overwrites" the config module so that the environment is already set.
+# Global `config` object to be used in the package.
-config: _config.Config = _config.get_config(
+config: _configuration.Config = _configuration.make_config(
     'testing' if _os.getenv('TESTING') else 'production',
 )
 

src/urban_meal_delivery/configuration.py

@@ -1,11 +1,12 @@
 """Provide package-wide configuration.
 
-This module is "protected" so that it is only used
+This module provides utils to create new `Config` objects
-via the `config` proxy at the package's top level.
+on the fly, mainly for testing and migrating!
 
-That already loads the correct configuration
+Within this package, use the `config` proxy at the package's top level
-depending on the current environment.
+to access the current configuration!
 """
+
 import datetime
 import os
 import random
@@ -20,8 +21,10 @@ dotenv.load_dotenv()
 
 def random_schema_name() -> str:
     """Generate a random PostgreSQL schema name for testing."""
-    return ''.join(
+    return 'temp_{name}'.format(
-        random.choice(string.ascii_lowercase) for _ in range(10)  # noqa:S311
+        name=''.join(
+            (random.choice(string.ascii_lowercase) for _ in range(10)),  # noqa:S311
+        ),
     )
 
 
@@ -44,6 +47,9 @@ class Config:
     # The PostgreSQL schema that holds the tables with the cleaned data.
     CLEAN_SCHEMA = os.getenv('CLEAN_SCHEMA') or 'clean'
 
+    ALEMBIC_TABLE = 'alembic_version'
+    ALEMBIC_TABLE_SCHEMA = 'public'
+
     def __repr__(self) -> str:
         """Non-literal text representation."""
         return '<configuration>'
@@ -68,8 +74,8 @@ class TestingConfig(Config):
     CLEAN_SCHEMA = os.getenv('CLEAN_SCHEMA_TESTING') or random_schema_name()
 
 
-def get_config(env: str = 'production') -> Config:
+def make_config(env: str = 'production') -> Config:
-    """Get the configuration for the package.
+    """Create a new `Config` object.
 
     Args:
         env: either 'production' or 'testing'; defaults to the first

tests/conftest.py

@@ -0,0 +1,12 @@
+"""Utils for testing the entire package."""
+
+import os
+
+from urban_meal_delivery import config
+
+
+if not os.getenv('TESTING'):
+    raise RuntimeError('Tests must be executed with TESTING set in the environment')
+
+if not config.TESTING:
+    raise RuntimeError('The testing configuration was not loaded')

tests/db/conftest.py

@@ -3,30 +3,49 @@
 import datetime
 
 import pytest
-from sqlalchemy import schema
+from alembic import command as migrations_cmd
+from alembic import config as migrations_config
 
 from urban_meal_delivery import config
 from urban_meal_delivery import db
 
 
-@pytest.fixture(scope='session')
+@pytest.fixture(scope='session', params=['all_at_once', 'sequentially'])
-def db_engine():
+def db_engine(request):
     """Create all tables given the ORM models.
 
     The tables are put into a distinct PostgreSQL schema
     that is removed after all tests are over.
 
     The engine used to do that is yielded.
+
+    There are two modes for this fixture:
+
+    - "all_at_once": build up the tables all at once with MetaData.create_all()
+    - "sequentially": build up the tables sequentially with `alembic upgrade head`
+
+    This ensures that Alembic's migration files are consistent.
     """
     engine = db.make_engine()
-    engine.execute(schema.CreateSchema(config.CLEAN_SCHEMA))
+
-    db.Base.metadata.create_all(engine)
+    if request.param == 'all_at_once':
+        engine.execute(f'CREATE SCHEMA {config.CLEAN_SCHEMA};')
+        db.Base.metadata.create_all(engine)
+    else:
+        cfg = migrations_config.Config('alembic.ini')
+        migrations_cmd.upgrade(cfg, 'head')
 
     try:
         yield engine
 
     finally:
-        engine.execute(schema.DropSchema(config.CLEAN_SCHEMA, cascade=True))
+        engine.execute(f'DROP SCHEMA {config.CLEAN_SCHEMA} CASCADE;')
+
+        if request.param == 'sequentially':
+            tmp_alembic_version = f'{config.ALEMBIC_TABLE}_{config.CLEAN_SCHEMA}'
+            engine.execute(
+                f'DROP TABLE {config.ALEMBIC_TABLE_SCHEMA}.{tmp_alembic_version};',
+            )
 
 
 @pytest.fixture

tests/test_config.py

@@ -2,7 +2,7 @@
 
 import pytest
 
-from urban_meal_delivery import _config as config_mod  # noqa:WPS450
+from urban_meal_delivery import configuration
 
 
 envs = ['production', 'testing']
@@ -11,7 +11,7 @@ envs = ['production', 'testing']
 @pytest.mark.parametrize('env', envs)
 def test_config_repr(env):
     """Config objects have the text representation '<configuration>'."""
-    config = config_mod.get_config(env)
+    config = configuration.make_config(env)
 
     assert str(config) == '<configuration>'
 
@@ -19,18 +19,18 @@ def test_config_repr(env):
 def test_invalid_config():
     """There are only 'production' and 'testing' configurations."""
     with pytest.raises(ValueError, match="'production' or 'testing'"):
-        config_mod.get_config('invalid')
+        configuration.make_config('invalid')
 
 
 @pytest.mark.parametrize('env', envs)
 def test_database_uri_set(env, monkeypatch):
     """Package does NOT emit warning if DATABASE_URI is set."""
     uri = 'postgresql://user:password@localhost/db'
-    monkeypatch.setattr(config_mod.ProductionConfig, 'DATABASE_URI', uri)
+    monkeypatch.setattr(configuration.ProductionConfig, 'DATABASE_URI', uri)
-    monkeypatch.setattr(config_mod.TestingConfig, 'DATABASE_URI', uri)
+    monkeypatch.setattr(configuration.TestingConfig, 'DATABASE_URI', uri)
 
     with pytest.warns(None) as record:
-        config_mod.get_config(env)
+        configuration.make_config(env)
 
     assert len(record) == 0  # noqa:WPS441,WPS507
 
@@ -38,16 +38,17 @@ def test_database_uri_set(env, monkeypatch):
 @pytest.mark.parametrize('env', envs)
 def test_no_database_uri_set(env, monkeypatch):
     """Package does not work without DATABASE_URI set in the environment."""
-    monkeypatch.setattr(config_mod.ProductionConfig, 'DATABASE_URI', None)
+    monkeypatch.setattr(configuration.ProductionConfig, 'DATABASE_URI', None)
-    monkeypatch.setattr(config_mod.TestingConfig, 'DATABASE_URI', None)
+    monkeypatch.setattr(configuration.TestingConfig, 'DATABASE_URI', None)
 
     with pytest.warns(UserWarning, match='no DATABASE_URI'):
-        config_mod.get_config(env)
+        configuration.make_config(env)
 
 
 def test_random_testing_schema():
-    """CLEAN_SCHEMA is randomized if not seti explicitly."""
+    """CLEAN_SCHEMA is randomized if not set explicitly."""
-    result = config_mod.random_schema_name()
+    result = configuration.random_schema_name()
 
     assert isinstance(result, str)
-    assert len(result) <= 10
+    assert result.startswith('temp_')
+    assert len(result) == 15