How to properly open / close files in pytest?-CodePudding

I have the following test case:

@pytest.mark.parametrize('filename', [
    ('test.pdf'),
    ('t est.pdf')
])
def test_should_work(filename: str):
    # given
    content_type = 'application/pdf'
    file = prepare_file_with_fixed_size(filename, MAX_FILE_SIZE)
    files = [('file', (filename, file, 'application/pdf'))]
    file_id = requests.post('my_url', files=files).json()['id']

    # when
    result = requests.get(f"{'my__url'}/{file_id}/raw")

    # then
    assert ...

    # finally
    file.close()
    os.remove(file.name)

def prepare_file_with_fixed_size(filename: str, size: int) -> BinaryIO:
    with open(filename, 'wb') as file:
        file.truncate(size)
    return open(filename, 'rb')

I am creating file for each test case and trying to remove it after its done in finally section. This works fine but... When test fail then file is not removed. I think it is not closed too. Simply my finally section is not executed.

Could someone help me to improve this test? I want some kind of "after all close and delete file" mechanism which gonna work independent of test results.

CodePudding user response：

You almost have the answer... you should read more about exception in python.

You have to add a try/catch/finally section:

def test_should_work(filename: str):
    # given
    content_type = 'application/pdf'
    try:
        file = prepare_file_with_fixed_size(filename, MAX_FILE_SIZE)
        files = [('file', (filename, file, 'application/pdf'))]
        file_id = requests.post('my_url', files=files).json()['id']

        # when
        result = requests.get(f"{'my__url'}/{file_id}/raw")

        # then
        assert ...

   except AssertionError as e:
       pass  # your exception will be caught here (only AssertionError)


   # finally
   finally: 
       # This section will always be executed
       file.close()
       os.remove(file.name)