突變在動態載入模組時沒有被殺死

這個範例演示動態載入模組導致突變存活。這個案例是 Cosmic-Ray 中尚未診斷完成的問題。更多資訊請參考 Issue #157

Reproducer

$ pip install https://github.com/sixty-north/cosmic-ray/zipball/b3c57a3
$ celery -A cosmic_ray.tasks.worker worker

$ cosmic-ray run --baseline=10 example.json sandwich/ham/ham.py -- tests
$ cosmic-ray report example.json
job ID 1:Outcome.SURVIVED:sandwich.ham.ham
command: cosmic-ray worker sandwich.ham.ham number_replacer 0 unittest -- tests
--- mutation diff ---
--- a/sandwich/ham/ham.py
+++ b/sandwich/ham/ham.py
@@ -3,6 +3,6 @@

 class Ham(object):

-    def __init__(self, pieces=10):
+    def __init__(self, pieces=11):
         self.pieces = pieces


total jobs: 1
complete: 1 (100.00%)
survival rate: 100.00%

驗證測試是成功的

這個範例中 test_control.py 正確的在程式碼手動修改以及執行時，偵測到突變。要驗證這個部份，請以下面的程式碼手動編輯 sandwitch/ham/ham.py 接著執行一次：

$ python -m unittest tests/test_control.py
F
======================================================================
FAIL: test_loading_via_importlib (tests.test_control.TestControl)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "~/example_01/tests/test_control.py", line 7, in test_loading_via_importlib
    self.assertEqual(ham_in_fridge.pieces, 10)
AssertionError: 11 != 10

----------------------------------------------------------------------
Ran 1 test in 0.000s

FAILED (failures=1)

程式碼

sandwich/ham/ham.py

__all__ = ['Ham']

class Ham(object):
    def __init__(self, pieces=10):
        self.pieces = pieces

sandwich/control.py

import os
import sys
import importlib

path = os.path.dirname(__file__)
path = os.path.join(path, "ham")
if not path in sys.path:
    sys.path.append(path)

module = importlib.import_module('ham')
ham_class = module.__dict__[module.__all__[0]]

tests/test_control.py

import sandwich.control
import unittest

class TestControl(unittest.TestCase):
    def test_loading_via_importlib(self):
        ham_in_fridge = sandwich.control.ham_class()
        self.assertEqual(ham_in_fridge.pieces, 10)


if __name__ == "__main__":
    unittest.main()