What is wrong with my code below?
I'm expecting assert call_func_once_with("b") to throw an error as call_func was passed 'a'. I confimed that the function was indeed called once and with argument 'a'.
from unittest.mock import Mock, patch
def call_func(x):
pass
@patch("__main__.call_func")
def test_call_func(call_func):
call_func("a")
assert call_func.called_once_with("b")
assert call_func.called == 1
print(call_func.call_args)
test_call_func()
Output:
call('a')
You're not the first person to notice strange things with these types of assertions (see Magic mock assert_called_once vs assert_called_once_with weird behaviour)
For what it's worth, I can only advise that you try to create a test class which inherits from unittest.TestCase and then use the assertEqual method to get more consistent test behaviour:
import unittest
from unittest.mock import patch, call
def call_func(x):
pass
class MyTests(unittest.TestCase):
@patch("__main__.call_func")
def test_call_func(self, call_func_mock):
call_func_mock("a")
# assert call_func_mock.called == 1
# assert call_func_mock.called_once_with("b")
self.assertEqual(call_func_mock.call_count, 1)
self.assertEqual(call_func_mock.call_args_list[0], call("b"))
print(call_func_mock.call_args)
unittest.main()
This gives the following (expected) results:
F
======================================================================
FAIL: test_call_func (__main__.MyTests)
----------------------------------------------------------------------
Traceback (most recent call last):
File "C:\Python36\lib\unittest\mock.py", line 1179, in patched
return func(*args, **keywargs)
File "C:/scratch.py", line 16, in test_call_func
self.assertEquals(call_func_mock.call_args_list[0], call("b"))
AssertionError: call('a') != call('b')
----------------------------------------------------------------------
Ran 1 test in 0.003s
FAILED (failures=1)
Process finished with exit code 1
