Django ignores router when running tests?

Question

I have a django application that uses 2 database connections:

1. To connect to the actual data the app is to produce
2. To a reference master data system, that

Answer 1

Use the --settings flag with the test command. In the path.to.test.py module, a la python manage.py test --settings=app.settings.test. There is no need to muck around with routes, just make sure that you invoke the tests with the settings flag whenever and where ever you call it.

In app.settings.test.py, redefine your DATABASES datastructure:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': '',
        'USER': '',
        'PASSWORD': '',
    },
    'mdm_db': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': '',
        'USER': '',
        'PASSWORD': '',
    },
}

This allows you to use a separate database when running tests. Additionally, if you use sqlite3 as your engine, you'll find that tests run very fast as the database is in memory.

Using sqlite3 databases for testing means that even hundreds of tests can be run within seconds. As a result, you can run your tests very frequently. I typically map a key to save my work and run my tests with one action:

map ,t :up\|!python manage.py test --settings=app.settings.test

Hope that is is helpful!

Answer 2

I solved this by changing the DATABASES.TEST definition. I added the TEST['MIRROR'] = 'default' to the mdm_db database entry.

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.oracle',
        'NAME': '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=%s)(PORT=1521)))(CONNECT_DATA=(SID=%s)))'
                % (get_env_variable('LIMS_MIGRATION_HOST'), get_env_variable('LIMS_MIGRATION_SID')),
        'USER': 'LIMS_MIGRATION',
        'PASSWORD': get_env_variable('LIMS_MIGRATION_PASSWORD'),
    },
    'mdm_db': {
        'ENGINE': 'django.db.backends.oracle',
        'NAME': '(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=GB3P)(PORT=1521)))'
                '(CONNECT_DATA=(SID=GB3P)))',
        'USER': 'MDM',
        'PASSWORD': get_env_variable('MDM_DB_PASSWORD'),
        'TEST': {
            'MIRROR': 'default',  # Added this setting
        }
    },
}

According to the documentation this option can be abused to skip database creation:

However, the replica database has been configured as a test mirror (using the MIRROR test setting), indicating that under testing, replica should be treated as a mirror of default.

When the test environment is configured, a test version of replica will not be created. Instead the connection to replica will be redirected to point at default.

Running my tests now skips creation of the second database.

Thanks for all the input!!

Answer 3

You could try to mock out the connection to the second database using python mocks?https://pypi.python.org/pypi/mock -- now part of the stdlib in python 3.