I've been pulling my hair out trying to figure out how to mock the sqlite3.Cursor
class specifically the fetchall
method.
Consider the following code sample
import sqlite3
from mock import Mock, patch
from nose.tools import assert_false
class Foo:
def check_name(name):
conn = sqlite3.connect('temp.db')
c = conn.cursor()
c.execute('SELECT * FROM foo where name = ?', name)
if len(c.fetchall()) > 0:
return True
return False
@patch('sqlite3.Cursor.fetchall', Mock(return_value=['John', 'Bob']))
def test_foo():
foo = Foo()
assert_false(foo.check_name('Cane'))
Running nosetests
results in no fun error
E
======================================================================
ERROR: temp.test_foo
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/koddsson/.virtualenvs/temp/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
self.test(*self.arg)
File "/home/koddsson/.virtualenvs/temp/lib/python2.7/site-packages/mock.py", line 1214, in patched
patching.__exit__(*exc_info)
File "/home/koddsson/.virtualenvs/temp/lib/python2.7/site-packages/mock.py", line 1379, in __exit__
setattr(self.target, self.attribute, self.temp_original)
TypeError: can't set attributes of built-in/extension type 'sqlite3.Cursor'
----------------------------------------------------------------------
Ran 1 test in 0.002s
FAILED (errors=1)
Should I not be able to mock the fetchall
method or am I doing something horribly wrong?