import unittest
from warnings import catch_warnings
from unittest.test.testmock.support import is_instance
from unittest.mock import MagicMock, Mock, patch, sentinel, mock_open, call
something = sentinel.Something
something_else = sentinel.SomethingElse
class WithTest(unittest.TestCase):
def test_with_statement(self):
with patch('%s.something' % __name__, sentinel.Something2):
self.assertEqual(something, sentinel.Something2, "unpatched")
self.assertEqual(something, sentinel.Something)
def test_with_statement_exception(self):
try:
with patch('%s.something' % __name__, sentinel.Something2):
self.assertEqual(something, sentinel.Something2, "unpatched")
raise Exception('pow')
except Exception:
pass
else:
self.fail("patch swallowed exception")
self.assertEqual(something, sentinel.Something)
def test_with_statement_as(self):
with patch('%s.something' % __name__) as mock_something:
self.assertEqual(something, mock_something, "unpatched")
self.assertTrue(is_instance(mock_something, MagicMock),
"patching wrong type")
self.assertEqual(something, sentinel.Something)
def test_patch_object_with_statement(self):
class Foo(object):
something = 'foo'
original = Foo.something
with patch.object(Foo, 'something'):
self.assertNotEqual(Foo.something, original, "unpatched")
self.assertEqual(Foo.something, original)
def test_with_statement_nested(self):
with catch_warnings(record=True):
with patch('%s.something' % __name__) as mock_something, patch('%s.something_else' % __name__) as mock_something_else:
self.assertEqual(something, mock_something, "unpatched")
self.assertEqual(something_else, mock_something_else,
"unpatched")
self.assertEqual(something, sentinel.Something)
self.assertEqual(something_else, sentinel.SomethingElse)
def test_with_statement_specified(self):
with patch('%s.something' % __name__, sentinel.Patched) as mock_something:
self.assertEqual(something, mock_something, "unpatched")
self.assertEqual(mock_something, sentinel.Patched, "wrong patch")
self.assertEqual(something, sentinel.Something)
def testContextManagerMocking(self):
mock = Mock()
mock.__enter__ = Mock()
mock.__exit__ = Mock()
mock.__exit__.return_value = False
with mock as m:
self.assertEqual(m, mock.__enter__.return_value)
mock.__enter__.assert_called_with()
mock.__exit__.assert_called_with(None, None, None)
def test_context_manager_with_magic_mock(self):
mock = MagicMock()
with self.assertRaises(TypeError):
with mock:
'foo' + 3
mock.__enter__.assert_called_with()
self.assertTrue(mock.__exit__.called)
def test_with_statement_same_attribute(self):
with patch('%s.something' % __name__, sentinel.Patched) as mock_something:
self.assertEqual(something, mock_something, "unpatched")
with patch('%s.something' % __name__) as mock_again:
self.assertEqual(something, mock_again, "unpatched")
self.assertEqual(something, mock_something,
"restored with wrong instance")
self.assertEqual(something, sentinel.Something, "not restored")
def test_with_statement_imbricated(self):
with patch('%s.something' % __name__) as mock_something:
self.assertEqual(something, mock_something, "unpatched")
with patch('%s.something_else' % __name__) as mock_something_else:
self.assertEqual(something_else, mock_something_else,
"unpatched")
self.assertEqual(something, sentinel.Something)
self.assertEqual(something_else, sentinel.SomethingElse)
def test_dict_context_manager(self):
foo = {}
with patch.dict(foo, {'a': 'b'}):
self.assertEqual(foo, {'a': 'b'})
self.assertEqual(foo, {})
with self.assertRaises(NameError):
with patch.dict(foo, {'a': 'b'}):
self.assertEqual(foo, {'a': 'b'})
raise NameError('Konrad')
self.assertEqual(foo, {})
class TestMockOpen(unittest.TestCase):
def test_mock_open(self):
mock = mock_open()
with patch('%s.open' % __name__, mock, create=True) as patched:
self.assertIs(patched, mock)
open('foo')
mock.assert_called_once_with('foo')
def test_mock_open_context_manager(self):
mock = mock_open()
handle = mock.return_value
with patch('%s.open' % __name__, mock, create=True):
with open('foo') as f:
f.read()
expected_calls = [call('foo'), call().__enter__(), call().read(),
call().__exit__(None, None, None)]
self.assertEqual(mock.mock_calls, expected_calls)
self.assertIs(f, handle)
def test_mock_open_context_manager_multiple_times(self):
mock = mock_open()
with patch('%s.open' % __name__, mock, create=True):
with open('foo') as f:
f.read()
with open('bar') as f:
f.read()
expected_calls = [
call('foo'), call().__enter__(), call().read(),
call().__exit__(None, None, None),
call('bar'), call().__enter__(), call().read(),
call().__exit__(None, None, None)]
self.assertEqual(mock.mock_calls, expected_calls)
def test_explicit_mock(self):
mock = MagicMock()
mock_open(mock)
with patch('%s.open' % __name__, mock, create=True) as patched:
self.assertIs(patched, mock)
open('foo')
mock.assert_called_once_with('foo')
def test_read_data(self):
mock = mock_open(read_data='foo')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
result = h.read()
self.assertEqual(result, 'foo')
def test_readline_data(self):
# Check that readline will return all the lines from the fake file
mock = mock_open(read_data='foo\nbar\nbaz\n')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
line1 = h.readline()
line2 = h.readline()
line3 = h.readline()
self.assertEqual(line1, 'foo\n')
self.assertEqual(line2, 'bar\n')
self.assertEqual(line3, 'baz\n')
# Check that we properly emulate a file that doesn't end in a newline
mock = mock_open(read_data='foo')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
result = h.readline()
self.assertEqual(result, 'foo')
def test_readlines_data(self):
# Test that emulating a file that ends in a newline character works
mock = mock_open(read_data='foo\nbar\nbaz\n')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
result = h.readlines()
self.assertEqual(result, ['foo\n', 'bar\n', 'baz\n'])
# Test that files without a final newline will also be correctly
# emulated
mock = mock_open(read_data='foo\nbar\nbaz')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
result = h.readlines()
self.assertEqual(result, ['foo\n', 'bar\n', 'baz'])
def test_read_bytes(self):
mock = mock_open(read_data=b'\xc6')
with patch('%s.open' % __name__, mock, create=True):
with open('abc', 'rb') as f:
result = f.read()
self.assertEqual(result, b'\xc6')
def test_readline_bytes(self):
m = mock_open(read_data=b'abc\ndef\nghi\n')
with patch('%s.open' % __name__, m, create=True):
with open('abc', 'rb') as f:
line1 = f.readline()
line2 = f.readline()
line3 = f.readline()
self.assertEqual(line1, b'abc\n')
self.assertEqual(line2, b'def\n')
self.assertEqual(line3, b'ghi\n')
def test_readlines_bytes(self):
m = mock_open(read_data=b'abc\ndef\nghi\n')
with patch('%s.open' % __name__, m, create=True):
with open('abc', 'rb') as f:
result = f.readlines()
self.assertEqual(result, [b'abc\n', b'def\n', b'ghi\n'])
def test_mock_open_read_with_argument(self):
# At one point calling read with an argument was broken
# for mocks returned by mock_open
some_data = 'foo\nbar\nbaz'
mock = mock_open(read_data=some_data)
self.assertEqual(mock().read(10), some_data)
def test_interleaved_reads(self):
# Test that calling read, readline, and readlines pulls data
# sequentially from the data we preload with
mock = mock_open(read_data='foo\nbar\nbaz\n')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
line1 = h.readline()
rest = h.readlines()
self.assertEqual(line1, 'foo\n')
self.assertEqual(rest, ['bar\n', 'baz\n'])
mock = mock_open(read_data='foo\nbar\nbaz\n')
with patch('%s.open' % __name__, mock, create=True):
h = open('bar')
line1 = h.readline()
rest = h.read()
self.assertEqual(line1, 'foo\n')
self.assertEqual(rest, 'bar\nbaz\n')
def test_overriding_return_values(self):
mock = mock_open(read_data='foo')
handle = mock()
handle.read.return_value = 'bar'
handle.readline.return_value = 'bar'
handle.readlines.return_value = ['bar']
self.assertEqual(handle.read(), 'bar')
self.assertEqual(handle.readline(), 'bar')
self.assertEqual(handle.readlines(), ['bar'])
# call repeatedly to check that a StopIteration is not propagated
self.assertEqual(handle.readline(), 'bar')
self.assertEqual(handle.readline(), 'bar')
if __name__ == '__main__':
unittest.main()