gistfile1.txt

def copy_to_temp(file_upload):
    tmp = tempfile.NamedTemporaryFile(delete=False)
    while True:
        data = file_upload.read(8192)
        tmp.write(data)
        if not data:
            break
    tmp.flush()
    return tmp

# I want to assert that
# - NamedTemporaryFile is called with delete=False
# - file_upload.read(8192) is called and returns ''
# - tmp.write is called with ''
# - tmp.flush is called
# - tmp is returned


=== Result

from nose.tools import *
from mock import Mock, patch

@patch('tempfile.NamedTemporaryFile')
def test_copy_to_temp(MockTempFile):
    tmp = MockTempFile.return_value
    file_upload = Mock()
    file_upload.read.return_value = ""

    result = copy_to_temp(file_upload)

    MockTempFile.assert_called_with(delete=False)
    tmp.write.assert_called_with("")
    assert tmp.flush.called
    assert tmp == result