Testify - A Testing Framework
PLEASE NOTE: Yelp is in the process of switching to py.test. We recommend you use it instead of Testify.
Testify is a replacement for Python's unittest module and nose. It is modeled after unittest, and existing unittest classes are fully supported.
However, Testify has features above and beyond unittest:
Class-level setup and teardown fixture methods, which are run only once for an entire class of test methods.
A decorator-based approach to fixture methods, enabling features like lazily-evaluated attributes and context managers for tests.
Enhanced test discovery. Testify can drill down into packages to find test cases (similiar to nose).
Support for detecting and running test suites, grouped by modules, classes, or individual test methods.
Support for splitting up tests into buckets for multiprocessing.
Pretty test runner output (hooray color!).
Extensible plugin system for adding additional functionality around reporting.
Comes complete with other handy testing utilities, including turtle (for mocking), code coverage integration, profiling, and numerous common assertion helpers for easier debugging.
More Pythonic naming conventions.
Example Test Case
from testify import * class AdditionTestCase(TestCase): @class_setup def init_the_variable(self): self.variable = 0 @setup def increment_the_variable(self): self.variable += 1 def test_the_variable(self): assert_equal(self.variable, 1) @suite('disabled', reason='ticket #123, not equal to 2 places') def test_broken(self): # raises 'AssertionError: 1 !~= 1.01' assert_almost_equal(1, 1.01, threshold=2) @teardown def decrement_the_variable(self): self.variable -= 1 @class_teardown def get_rid_of_the_variable(self): self.variable = None if __name__ == "__main__": run()
Testify will discover and run
unittests without any code changes, just
point it to a directory containing your tests:
$ testify my_unittests/foo_test.py
To take advantage of more advanced Testify features, just replace
Testify provides the following fixtures for your enjoyment:
@setup: Run before each individual test method on the
TestCase(that is, all methods that begin with 'test').
setup, but run after each test completes (regardless of success or failure).
@class_setup: Run before a
TestCasebegins executing its tests. Note that this not a class method; you still have access to the same
TestCaseinstance as your tests.
class_setup, but run after all tests complete (regardless of success or failure).
@setup_teardown: A context manager for individual tests, where test execution occurs during the yield. For example:
@setup_teardown def mock_something(self): with mock.patch('foo') as foo_mock: self.foo_mock = foo_mock yield # this is where you would do teardown things
setup_teardown, but all of the
TestCase's methods are run when this yields.
@let: This declares a lazily-evaluated attribute of the
TestCase. When accessed, this attribute will be computed and cached for the life of the test (including setup and teardown). For example:
@let def expensive_attribute(self): return expensive_function_call() def test_something(self): assert self.expensive_attribute def test_something_else(self): # no expensive call assert True
Order of Execution
In pseudo code, Testify follows this schedule when running your tests:
Run all 'class_setup' methods Enter all 'class_setup_teardown' context managers For each method beginning with 'test': Run all 'setup' methods Enter all 'setup_teardown' context managers Run the method and record failure or success Exit all 'setup_teardown' context managers Run all 'teardown' methods Exit all 'class_setup_teardown' context managers Run all 'class_teardown' methods
Your fixtures are just decorated methods, so they can be inherited and overloaded as expected. When you introduce subclasses and mixins into the... mix, things can get a little crazy. For this reason, Testify makes a couple guarantees about how your fixtures are run:
A subclass's fixture context is always contained within its parent's fixture context (as determined by the usual MRO). That is, fixture context is pushed and popped in FILO order.
Fixtures of the same type (and defined at the same level in the class heirarchy) will be run in the order they are defined on the class.