Integrating Betamax with Test Frameworks¶
It’s nice to have a way to integrate libraries you use for testing into your testing frameworks. Having considered this, the authors of and contributors to Betamax have included integrations in the package. Betamax comes with integrations for py.test and unittest. (If you need an integration for another framework, please suggest it and send a patch!)
PyTest Integration¶
New in version 0.5.0.
Changed in version 0.6.0.
When you install Betamax, it now installs two py.test fixtures by default.
To use it in your tests you need only follow the instructions on pytest’s
documentation. To use the betamax_session
fixture for an entire class of
tests you would do:
# tests/test_http_integration.py
import pytest
@pytest.mark.usefixtures('betamax_session')
class TestMyHttpClient:
def test_get(self, betamax_session):
betamax_session.get('https://httpbin.org/get')
This will generate a cassette name for you, e.g.,
tests.test_http_integration.TestMyHttpClient.test_get
. After running this
test you would have a cassette file stored in your cassette library directory
named tests.test_http_integration.TestMyHttpClient.test_get.json
. To use
this fixture at the module level, you need only do
# tests/test_http_integration.py
import pytest
pytest.mark.usefixtures('betamax_session')
class TestMyHttpClient:
def test_get(self, betamax_session):
betamax_session.get('https://httpbin.org/get')
class TestMyOtherHttpClient:
def test_post(self, betamax_session):
betamax_session.post('https://httpbin.org/post')
If you need to customize the recorder object, however, you can instead use the
betamax_recorder
fixture:
# tests/test_http_integration.py
import pytest
pytest.mark.usefixtures('betamax_recorder')
class TestMyHttpClient:
def test_post(self, betamax_recorder):
betamax_recorder.current_cassette.match_options.add('json-body')
session = betamax_recorder.session
session.post('https://httpbin.org/post', json={'foo': 'bar'})
Unittest Integration¶
New in version 0.5.0.
When writing tests with unittest, a common pattern is to either import
unittest.TestCase
or subclass that and use that subclass in your
tests. When integrating Betamax with your unittest testsuite, you should do
the following:
from betamax.fixtures import unittest
class IntegrationTestCase(unittest.BetamaxTestCase):
# Add the rest of the helper methods you want for your
# integration tests
class SpecificTestCase(IntegrationTestCase):
def test_something(self):
# Test something
The unittest integration provides the following attributes on the test case instance:
session
the instance ofBetamaxTestCase.SESSION_CLASS
created for that test.recorder
the instance ofbetamax.Betamax
created.
The integration also generates a cassette name from the test case class name
and test method. So the cassette generated for the above example would be
named SpecificTestCase.test_something
. To override that behaviour, you
need to override the
generate_cassette_name()
method in
your subclass.
The default path to save cassette is ./vcr/cassettes. To override the path uses the follow code at the top of file.
with betamax.Betamax.configure() as config:
config.cassette_library_dir = 'your/path/here'
If you are subclassing requests.Session
in your application, then it
follows that you will want to use that in your tests. To facilitate this, you
can set the SESSION_CLASS
attribute. To give a fuller example, let’s say
you’re changing the default cassette name and you’re providing your own
session class, your code might look like:
from betamax.fixtures import unittest
from myapi import session
class IntegrationTestCase(unittest.BetamaxTestCase):
# Add the rest of the helper methods you want for your
# integration tests
SESSION_CLASS = session.MyApiSession
def generate_cassette_name(self):
classname = self.__class__.__name__
method = self._testMethodName
return 'integration_{0}_{1}'.format(classname, method)