Qfyilyi

I installed pytest-mock and am trying to try using mocker to function as patch does, but I get "Type Error: Need a valid target to patch. You supplied 'return a + b'"

   # test_capitalize.py

   import time





 def sum( a, b):

    time.sleep(10)

    return a + b



 def test_sum(mocker):

    mocker.patch('return a + b');

    assertEqual(sum(2,3), 9)

patch requires a path to the function being patched. You could do something like this:

import pytest





def sum(a, b):

    return a + b





def test_sum1(mocker):

    mocker.patch(__name__ + ".sum", return_value=9)

    assert sum(2, 3) == 9





def test_sum2(mocker):

    def crazy_sum(a, b):

        return b + b



    mocker.patch(__name__ + ".sum", side_effect=crazy_sum)

    assert sum(2, 3) == 6

Result:

$ pytest -v patch_test.py

============= test session starts ==============

platform cygwin -- Python 3.6.4, pytest-3.10.1, py-1.7.0, pluggy-0.8.0 -- /usr/bin/python3

cachedir: .pytest_cache

rootdir: /home/xyz/temp, inifile:

plugins: mock-1.10.0, cov-2.6.0

collected 2 items



patch_test.py::test_sum1 PASSED          [ 50%]

patch_test.py::test_sum2 PASSED          [100%]



=========== 2 passed in 0.02 seconds ===========