VCR

Provides Mixins and TestCases for snapshot testing outgoing HTTP requests with VCR.

Depends on vcrpy and requests, but is also usable with other HTTP libraries than requests.

Note

The sub-dependencies will come automatically with the vcr extras: maykin-common[vcr]. Because this is a test tool, only include it in your CI and dev dependencies. Don’t include the vcr extra in the base dependencies of your project.

class maykin_common.vcr.SimpleVCRTestCase(*args: Any, **kwargs: Any)

A Django SimpleTestCase with the VCRMixin and a vcr tag.

Use this for testing “client code”.

class maykin_common.vcr.TransactionVCRTestCase(*args: Any, **kwargs: Any)

A Django TestCase with the VCRMixin and a vcr tag.

Use this only if you really need it. i.e when you’re actually testing the transactional behaviour of your app.

class maykin_common.vcr.VCRMixin(*args: Any, **kwargs: Any)

Mixin to use VCR cassettes to record HTTP requests/responses.

VCR_FILTER_HEADERS: ClassVar[Collection[str]] = frozenset({'Authorization', 'x-api-key'})

Default set of request headers to filter out.

Passed to the filter_headers kwarg of VCR by default.

VCR_RECORD_MODE: vcr.config.RecordMode

Defaults to VCR_RECORD_MODE env variable or RecordMode.NONE. To (re-)record throw away the cassettes and set to RecordMode.ONCE

VCR_TEST_FILES: Path | None = None

Cassettes will be stored in

VCR_TEST_FILES/vcr_cassettes/{test class name}/{test method name}.yaml

If left None, a files directory at the same level as the test class file will be used.

vcr_enabled: bool

Easy toggle to temporarily turn vcr off during development or debugging. So True does not enable recording “episodes” that would otherwise not be recorded.

vcr_raises(exception: Callable[[], Exception]=<class 'requests.exceptions.RequestException'>) → AbstractContextManager[vcr.cassette.Cassette]

Simulate occurrence of an error during HTTP request.

Example:

from requests.exceptions import SSLError, Timeout

# sometimes people let certificates expire
with self.vcr_raises(SSLError):
    response = function_under_test_that_uses_requests()

# or services/connections are down
with self.vcr_raises(Timeout):
    response = function_under_test_that_uses_requests()

Note

Instead of performing and recording a request, this raises an exception. So there will be no request nor cassette!

class maykin_common.vcr.VCRTestCase(*args: Any, **kwargs: Any)

A Django TestCase with the VCRMixin and a vcr tag.

Use this if your Model may do HTTP requests.