This is a pytest plugin, that enables you to test your code that relies on a running PostgreSQL Database. It allows you to specify fixtures for PostgreSQL process and client.

Install with:

pip install pytest-postgresql

You will also need to install psycopg2, or one of its alternative packagings such as psycopg2-binary (pre-compiled wheels) or psycopg2cffi (CFFI based, useful on PyPy).

Plugin contains three fixtures:

• postgresql - it's a client fixture that has functional scope. After each test it ends all leftover connections, and drops test database from PostgreSQL ensuring repeatability. This fixture returns already connected psycopg2 connection.
• postgresql_proc - session scoped fixture, that starts PostgreSQL instance at it's first use and stops at the end of the tests.
• postgresql_nooproc - a nooprocess fixture, that's connecting to already running postgresql instance. For example on dockerized test environments, or CI providing postgresql services

Simply include one of these fixtures into your tests fixture list.

You can also create additional postgresql client and process fixtures if you'd need to:

from pytest_postgresql import factories

postgresql_my_proc = factories.postgresql_proc(
    port=None, unixsocketdir='/var/run')
postgresql_my = factories.postgresql('postgresql_my_proc')

Sample test

def test_example_postgres(postgresql):
    """Check main postgresql fixture."""
    cur = postgresql.cursor()
    cur.execute("CREATE TABLE test (id serial PRIMARY KEY, num integer, data varchar);")
    postgresql.commit()
    cur.close()

If you want the database fixture to be automatically populated with your schema:

postgresql_my_with_schema = factories.postgresql('postgresql_my_proc', load=['schemafile.sql', 'otherschema.sql'])

If you've got other programmatic ways to populate the database, you would need an additional fixture, that will take care of that:

@pytest.fixture(scope='function')
def db_session(postgresql):
    """Session for SQLAlchemy."""
    from pyramid_fullauth.models import Base  # pylint:disable=import-outside-toplevel

    # NOTE: this fstring assumes that psycopg2 >= 2.8 is used. Not sure about it's support in psycopg2cffi (PyPy)
    connection = f'postgresql+psycopg2://{postgres.info.user}:@{postgres.info.host}:{postgres.info.port}/{postgres.info.dbname}'

    engine = create_engine(connection, echo=False, poolclass=NullPool)
    pyramid_basemodel.Session = scoped_session(sessionmaker(extension=ZopeTransactionExtension()))
    pyramid_basemodel.bind_engine(
        engine, pyramid_basemodel.Session, should_create=True, should_drop=True)

    yield pyramid_basemodel.Session

    transaction.commit()
    Base.metadata.drop_all(engine)

See the original code at pyramid_fullauth. Depending on your needs, that in between code can fire alembic migrations in case of sqlalchemy stack or any other code

Some projects are using already running postgresql servers (ie on docker instances). In order to connect to them, one would be using the postgresql_nooproc fixture.

postgresql_external = factories.postgresql('postgresql_nooproc')

By default the postgresql_nooproc fixture would connect to postgresql instance using 5432 port. Standard configuration options apply to it.

These are the configuration options that are working on all levels with the postgresql_nooproc fixture:

You can define your settings in three ways, it's fixture factory argument, command line option and pytest.ini configuration option. You can pick which you prefer, but remember that these settings are handled in the following order:

• Fixture factory argument
• Command line option
• Configuration option in your pytest.ini file

Example usage:

• pass it as an argument in your own fixture

  postgresql_proc = factories.postgresql_proc(
      port=8888)

• use --postgresql-port command line option when you run your tests

  py.test tests --postgresql-port=8888

• specify your port as postgresql_port in your pytest.ini file.

  To do so, put a line like the following under the [pytest] section of your pytest.ini:

  [pytest]
  postgresql_port = 8888

It is possible and appears it's used in other libraries for tests, to maintain database state with the use of the pytest-postgresql database managing functionality:

For this import DatabaseJanitor and use its init and drop methods:

from pytest_postgresql.factories import DatabaseJanitor

# variable definition

janitor = DatabaseJanitor(user, host, port, db_name, version)
janitor.init()
# your code, or yield
janitor.drop()
# at this moment you'll have clean database step

or use it as a context manager:

from pytest_postgresql.factories import DatabaseJanitor

# variable definition

with DatabaseJanitor(user, host, port, db_name, version):
    # do something here

• Bug tracker: https://github.com/ClearcodeHQ/pytest-postgresql/issues