pytest-postgresql 2.5.1

Postgresql fixtures and fixture factories for Pytest.

pytest-postgresql

Package status

What is this?

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.

How to use

Warning

Tested on PostgreSQL versions > 9.x. See tests for more details.

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')

Note

Each PostgreSQL process fixture can be configured in a different way than the others through the fixture factory arguments.

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'])

Note

The database will still be dropped each time.

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

Connecting to already existing postgresql database

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:

Configuration

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

Configuration options

PostgreSQL option	Fixture factory argument	Command line option	pytest.ini option	Noop process fixture	Default
Path to executable	executable	–postgresql-exec	postgresql_exec		/usr/lib/postgresql/9.1/bin/pg_ctl
host	host	–postgresql-host	postgresql_host	yes	127.0.0.1
port	port	–postgresql-port	postgresql_port	yes (5432)	random
postgresql user	user	–postgresql-user	postgresql_user	yes	postgres
password	password	–postgresql-password	postgresql_password	yes
Starting parameters	startparams	–postgresql-startparams	postgresql_startparams		-w
Log filename’s prefix	logsprefix	–postgresql-logsprefix	postgresql_logsprefix
Location for unixsockets	unixsocket	–postgresql-unixsocketdir	postgresql_unixsocketdir		$TMPDIR
Database name	db_name	–postgresql-dbname	postgresql_dbname		test
Default Schema	load	–postgresql-load	postgresql_load
PostgreSQL connection options	options	–postgresql-options	postgresql_options	yes

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

Maintaining database state outside of the fixtures

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

Note

DatabaseJanitor manages the state of the database, but you’ll have to create connection to use in test code yourself.

Package resources

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

CHANGELOG

2.5.1

• [fix] Added LC_* env vars to running initdb and other utilities. Now all tools and server are using same, C locale

2.5.0

• [feature] Ability to define default schema to initialize database with

• [docs] Added more examples to readme on how to use the plugin

2.4.1

• [enhancement] extract NoopExecutor into it’s own submodule

• [bugfix] Ignore occasional ProcessFinishedWithError error on executor exit.

• [bugfix] Fixed setting custom password for process fixture

• [bugfix] Fix version detection, to allow for two-digit minor version part

2.4.0

• [feature] Drop support for pyhon 3.5

• [enhancement] require at least mirakuru 2.3.0 (executor’s stop method parameter’s change)

• [bug] pass password to DatabaseJanitor in client’s factory

2.3.0

• [feature] Allow to set password for postgresql. Use it throughout the flow.

• [bugfix] Default Janitor’s connections to postgres database. When using custom users, postgres attempts to use user’s database and it might not exist.

• [bugfix] NoopExecutor connects to read version by context manager to properly handle cases where it can’t connect to the server.

2.2.1

• [bugfix] Fix drop_postgresql_database to actually use DatabaseJanitor.drop instead of an init

2.2.0

• [feature] ability to properly connect to already existing postgresql server using postgresql_nooproc fixture.

2.1.0

• [enhancement] Gather helper functions maintaining postgresql database in DatabaseJanitor class.

• [deprecate] Deprecate init_postgresql_database in favour of DatabaseJanitor.init

• [deprecate] Deprecate drop_postgresql_database in favour of DatabaseJanitor.drop

2.0.0

• [feature] Drop support for python 2.7. From now on, only support python 3.5 and up

• [feature] Ability to configure database name through plugin options

• [enhancement] Use tmpdir_factory. Drop logsdir parameter

• [ehnancement] Support only Postgresql 9.0 and up

• [bugfix] Always start postgresql with LC_ALL, LC_TYPE and LANG set to C.UTF-8. It makes postgresql start in english.

1.4.1

• [bugfix] Allow creating test databse with hyphens

1.4.0

• [enhancements] Ability to configure additional options for postgresql process and connection

• [bugfix] - removed hard dependency on psycopg2, allowing any of its alternative packages, like psycopg2-binary, to be used.

• [maintenance] Drop support for python 3.4 and use 3.7 instead

1.3.4

• [bugfix] properly detect if executor running and clean after executor is being stopped

  Note

  Previously if a test failed, there was a possibility of the executor being removed when python was closing, causing it to print ignored errors on already unloaded modules.

1.3.3

• [enhancement] use executor’s context manager to start/stop postrgesql server in a fixture

1.3.2

• [bugfix] version regexp to correctly catch postgresql 10

1.3.1

• [enhancement] explicitly turn off logging_collector

1.3.0

• [feature] pypy compatibility

1.2.0

• [bugfix] - disallow connection to database before it gets dropped.

  Note

  Otherwise it caused random test subprocess to connect again and this the drop was unsucessfull which resulted in many more test failes on setup.

• [cleanup] - removed path.py dependency

1.1.1

• [bugfix] - Fixing the default pg_ctl path creation

1.1.0

• [feature] - migrate usage of getfuncargvalue to getfixturevalue. require at least pytest 3.0.0

1.0.0

• create command line and pytest.ini configuration options for postgresql starting parameters

• create command line and pytest.ini configuration options for postgresql username

• make the port random by default

• create command line and pytest.ini configuration options for executable

• create command line and pytest.ini configuration options for host

• create command line and pytest.ini configuration options for port

• Extracted code from pytest-dbfixtures