RFL.build 1.8.0

Rackslab Foundation Library: build package

RFL: build package

Utilities to help backport builds of Python projects.

rfl.build.testing subpackage

The rfl.build.testing subpackage provides reusable helpers for writing unit tests in downstream projects. It is installable library code shipped with RFL.build.

This is distinct from rfl.tests under src/build/rfl/tests/, which contains unit tests for the build package itself.

Unittest parameterization (rfl.build.testing.params)

The params module provides the expand decorator to run the same test logic with multiple argument sets, as a maintained alternative to the unmaintained third-party parameterized library.

Import:

from rfl.build.testing.params import expand

Apply expand on a test method with a case list. Each case is passed as positional arguments to the method (a scalar is wrapped in a one-tuple):

import unittest

from rfl.build.testing.params import expand


class TestValues(unittest.TestCase):
    @expand([1, 2, 3])
    def test_is_positive(self, value):
        self.assertGreater(value, 0)

cases may be an iterable or a callable returning an iterable. At decoration time, expand injects one test method per case into the enclosing namespace. The template method is not collected by unittest (__test__ is set to False and the binding is not kept).

Generated names follow {method}_{index:03d}_{slug}, where slug is derived from all case values (for example test_is_positive_001_1 and test_is_positive_002_2).

Options:

• name_func(func, index, case) — return the generated method name. index is the 1-based case index.
• skip_on_empty=True — when cases is empty, mark the template as non-runnable instead of raising ValueError.

Example with multiple argument tuples:

class TestApi(unittest.TestCase):
    @expand([("1.0", "a"), ("2.0", "b")])
    def test_response(self, version, variant):
        ...

The result of expand(cases) is itself a decorator and may be assigned to a name to reuse the same case list on several test methods (similar to parameterized.expand):

http_verbs = expand(["get", "post"])


class TestHttpMethods(unittest.TestCase):
    @http_verbs
    def test_endpoint(self, verb):
        response = self.client.open("/resource", method=verb)
        self.assertEqual(response.status_code, 200)

A callable case source works the same way when building a shared decorator:

def version_combinations():
    return [("1.0", "a"), ("2.0", "b")]


all_versions = expand(version_combinations)


class TestApi(unittest.TestCase):
    @all_versions
    def test_response(self, version, variant):
        ...