pytest 与来自命令行和装置的数据库详细信息

Question

I am trying to initialize the db for pytest through values passed from command line. I cannot specify the values in a different test setting.py, nor can I specify it in TEST option in settings.py; it is only available through command line.

I have setup extra command line options in confttest.py, to get the db details:

def pytest_addoption(parser):
    parser.addoption(
        "--dbconnection", action="store", default = "novalue", help="test db value"
    )

Is there any way I can access these values in conftest.py? AFAIK, I can use fixtures to get the value in the test, but I would like to override django_db_modify_db_settings to change the database, with these command line arguments.

Is this possible? Is the database initialized before the command line is processed? I tried some experiments and it does look so. Is there any other workaround to getting this working?

Answer 1

Is there any way I can access these values in conftest.py?

You can access the command line arguments in all fixtures (via request.config ) and (most) hook impls.

Is the database initialized before the command line is processed?

No, the database is initialized a lot later after the command line was parsed. The command line args become accessible in pytest_configure hooks, and the database connection is not initialized before the django_db_setup fixture, so not before the first invocation of pytest_runtest_setup hooks.

Example, extended from your addopt hook:

import pytest


def pytest_addoption(parser):
    parser.addoption(
        "--dbconnection", action="store", default = "novalue", help="test db value"
    )


@pytest.fixture(scope='session')
def django_db_modify_db_settings(request):
    from django.conf import settings
    testdb_settings = settings.DATABASES['default']['TEST']
    dbconn = request.config.getoption('--dbconnection')
    if dbconn == 'infile':
        testdb_settings['NAME'] = '/tmp/testdb.sqlite'
    elif dbconn == 'inmem':
        testdb_settings['NAME'] = ':memory:'
    else:
        raise RuntimeError('Unknown option value.')

Running pytest --dbconnection=inmem will use the in-memory db, running pytest --dbconnection=infile will use the file (you can rerun with --reuse-db to verify the db file is created).