タプルを返すメソッドを単体テストしようとすると、コードが正しいタプル インデックスにアクセスするかどうかを確認しようとすると、python は予想される呼び出しを評価して文字列に変換しようとします。
call().methodA().__getitem__(0)
'().methodA'
アサーションのために私のexpected_calls
リストに変換されてしまいます。
提供されているサンプル コードでは、出力とトレースバックが生成されます。
expected_calls=[call().methodA(), '().methodA']
result_calls=[call().methodA(), call().methodA().__getitem__(0)]
======================================================================
ERROR: test_methodB (badMockCalls.Test_UsingToBeMocked_methods)
----------------------------------------------------------------------
Traceback (most recent call last):
File "C:\dev\workspace\TestCode\src\badMockCalls.py", line 43, in test_methodB
self.assertListEqual(expected_calls, self.result_calls)
File "C:\Python33\lib\unittest\case.py", line 844, in assertListEqual
self.assertSequenceEqual(list1, list2, msg, seq_type=list)
File "C:\Python33\lib\unittest\case.py", line 764, in assertSequenceEqual
if seq1 == seq2:
File "C:\Python33\lib\unittest\mock.py", line 1927, in __eq__
first, second = other
ValueError: too many values to unpack (expected 2)
----------------------------------------------------------------------
Ran 1 test in 0.006s
FAILED (errors=1)
methodB が self.tbm.methodA()[0] を適切に呼び出していることを主張するにはどうすればよいですか?
コード例 (Python 3.3.2):
import unittest
from unittest.mock import call, patch
import logging
log = logging.getLogger(__name__)
log.setLevel(logging.DEBUG)
_ch = logging.StreamHandler()
_ch.setLevel(logging.DEBUG)
log.addHandler(_ch)
class ToBeMocked(): # external resource that can't be changed
def methodA(self):
return (1,)
class UsingToBeMocked(): # project code
def __init__(self):
self.tbm = ToBeMocked()
def methodB(self):
value = self.tbm.methodA()[0]
return value
class Test_UsingToBeMocked_methods(unittest.TestCase):
def setUp(self):
self.patcher = patch(__name__ + '.ToBeMocked')
self.mock_ToBeMocked = self.patcher.start()
self.utbm = UsingToBeMocked()
# clear out the mock_calls list from the constructor calls
self.mock_ToBeMocked.mock_calls = []
# set result to always point to the mock_calls that we are testing
self.result_calls = self.mock_ToBeMocked.mock_calls
def tearDown(self):
self.patcher.stop()
def test_methodB(self):
self.utbm.methodB()
# make sure the correct sequence of calls is made with correct parameters
expected_calls = [call().methodA(),
call().methodA().__getitem__(0)]
log.debug('expected_calls=' + str(expected_calls))
log.debug(' result_calls=' + str(self.result_calls))
self.assertListEqual(expected_calls, self.result_calls)
if __name__ == "__main__":
unittest.main()