send_from_directory unclosed file error about flask HOT 3 CLOSED

Call response.close() at the end. See Flask itself for examples of this in tests.

from flask.

Call response.close() at the end. See Flask itself for examples of this in tests.

@davidism, I assume you are referring to the call to rv.close() in the test_send_from_directory code.

Unfortunately, the call to send_from_directory and the associated close both happen in the test code proper. When called by production code the call to response.close() cannot be done without error. When I modify download_resources to the following it causes additional errors:

@app.route('/<path:name>')
def download_resources(name):
    response = send_from_directory('resources', name)
    response.close()
    return response

Error:

self = <werkzeug.wsgi.FileWrapper object at 0x10c061150>

    def __next__(self) -> bytes:
>       data = self.file.read(self.buffer_size)
E       ValueError: read of closed file

venv/lib/python3.11/site-packages/werkzeug/wsgi.py:332: ValueError

The documentation does not mention a call to response.close().

Other documentation similarly does not call response.close().

It seems to me that the rv.close() in Flask's test case masks the unclosed file error, as you are not using send_from_directory via an external call like a Flask app would.

Thoughts?

from flask.

You don't call it in your application, only in your test. WSGI servers close the response automatically, the test client cannot.

from flask.