How to stop all tests from inside a test or setUp using unittest?

Question

I'm extending the python 2.7 unittest framework to do some function testing. One of the things I would like to do is to stop all the tests from running inside of a test, and inside of a setUpClass() method. Sometimes if a test fails, the program is so broken it is no longer of any use to keep testing, so I want to stop the tests from running.

I noticed that a TestResult has a shouldStop attribute, and a stop() method, but I'm not sure how to get access to that inside of a test.

Does anyone have any ideas? Is there a better way?

Answer 1

In case you are interested, here is a simple example how you could make a decision yourself about exiting a test suite cleanly with py.test:

# content of test_module.py
import pytest
counter = 0
def setup_function(func):
    global counter
    counter += 1
    if counter >=3:
        pytest.exit("decided to stop the test run")

def test_one():
    pass
def test_two():
    pass
def test_three():
    pass

and if you run this you get:

$ pytest test_module.py 
============== test session starts =================
platform linux2 -- Python 2.6.5 -- pytest-1.4.0a1
test path 1: test_module.py

test_module.py ..

!!!! Exit: decided to stop the test run !!!!!!!!!!!!
============= 2 passed in 0.08 seconds =============

You can also put the py.test.exit() call inside a test or into a project-specific plugin.

Sidenote: py.test natively supports py.test --maxfail=NUM to implement stopping after NUM failures.

Sidenote2: py.test has only limited support for running tests in the traditional unittest.TestCase style.