pytest-mysql

What is this?

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

Warning

Only MySQL 5.7.6 and up are supported. For older versions, please use pytest-mysql 2.0.3 Although Pull Request to add back support for older MySQL versions are welcome.

How to use

Plugin contains two fixtures

• mysql - it's a client fixture that has functional scope. After each test drops test database from MySQL ensuring repeatability.
• mysql_proc - session scoped fixture, that starts MySQL instance at it's first use and stops at the end of the tests.
• mysql_noproc - session scoped fixtures, that allows to connect to already existing MySQL instance, and cleans the database at the end of the tests

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

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

from pytest_mysql import factories
from getpass import getuser()

mysql_my_proc = factories.mysql_proc(
    port=None, user=getuser())
mysql_my = factories.mysql('mysql_my_proc')

Note

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

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

MySQL/MariaDB option	Fixture factory argument	Command line option	pytest.ini option	Noop process fixture	Default
Path to executable	mysqld_exec	--mysql-mysqld	mysql_mysqld		mysqld
Path to safe executable	mysqld_safe	--mysql-mysqld-safe	mysql_mysqld_safe		mysqld_safe
Path to mysql_install_db for legacy installations	install_db	--mysql-install-db	mysql_install_db		mysql_install_db
Path to Admin executable	admin_executable	--mysql-admin	mysql_admin		mysqladmin
Database hostname	host	--mysql-host	mysql_host	yes	localhost
Database port	port	--mysql-port	mysql_port	yes (3306)	random
MySQL user to work with	user	--mysql-user	mysql_user		root
User's password	passwd	--mysql-passwd	mysql_passwd
Test database name	dbname	--mysql-dbname	mysql_dbname		test
Starting parameters	params	--mysql-params	mysql_params
Log directory location [DEPRECATED]	logsdir	--mysql-logsdir	mysql_logsdir		$TMPDIR

Example usage:

• pass it as an argument in your own fixture

  mysql_proc = factories.mysql_proc(
      port=8888)

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

  py.test tests --mysql-port=8888

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

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

  [pytest]
  mysql_port = 8888

Examples

Populating database for tests

With SQLAlchemy

This example shows how to populate database and create an SQLAlchemy's ORM connection:

Sample below is simplified session fixture from pyramid_fullauth tests:

from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker
from sqlalchemy.pool import NullPool
from zope.sqlalchemy import register


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

    # assumes setting, these can be obtained from pytest-mysql config or mysql_proc
    connection = f'mysql+mysqldb://root:@127.0.0.1:3307/tests?charset=utf8'

    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)


@pytest.fixture
def user(db_session):
    """Test user fixture."""
    from pyramid_fullauth.models import User
    from tests.tools import DEFAULT_USER

    new_user = User(**DEFAULT_USER)
    db_session.add(new_user)
    transaction.commit()
    return new_user


def test_remove_last_admin(db_session, user):
    """
    Sample test checks internal login, but shows usage in tests with SQLAlchemy
    """
    user = db_session.merge(user)
    user.is_admin = True
    transaction.commit()
    user = db_session.merge(user)

    with pytest.raises(AttributeError):
        user.is_admin = False

Note

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

Connecting to MySQL/MariaDB (in a docker)

To connect to a docker run MySQL and run test on it, use noproc fixtures.

docker run --name some-db -e MYSQL_ALLOW_EMPTY_PASSWORD=yes -d mysql --expose 3306

docker run --name some-db -e MARIADB_ALLOW_EMPTY_PASSWORD=yes -d mariadb --expose 3306

This will start MySQL in a docker container, however using a MySQL installed locally is not much different.

In tests, make sure that all your tests are using mysql_noproc fixture like that:

mysql_in_docker = factories.mysql_noproc()
mysql = factories.mysql("mysql_in_docker")


def test_mysql_docker(mysql):
    """Run test."""
    cur = mysql.cursor()
    cur.query("CREATE TABLE pet (name VARCHAR(20), owner VARCHAR(20), species VARCHAR(20), sex CHAR(1), birth DATE, death DATE);")
    mysql.commit()
    cur.close()

And run tests:

pytest --mysql-host=127.0.0.1

Running on Docker/as root

Unfortunately, running MySQL as root (thus by default on docker) is not possible. MySQL (and MariaDB as well) will not allow it.

USER nobody

This line should switch your docker process to run on user nobody. See this comment for example

Package resources

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

Release

Install pipenv and --dev dependencies first, Then run:

pipenv run tbump [NEW_VERSION]