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.
• 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

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.

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
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

Package resources

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