slowed tests

Adding the whitenoise middleware can greatly slow down your tests. If you have processes static previously and your static directory is full of static files. Then the middleware, on each test method, process the list of files over and over. So your tests are now slowed by a function of how many static files you have.

On startup this is called:

    def update_files_dictionary(self, root, prefix):
        for directory, _, filenames in os.walk(root, followlinks=True):
            for filename in filenames:
                path = os.path.join(directory, filename)
                url = prefix + os.path.relpath(path, root).replace('\\', '/')
                self.files[url] = self.get_static_file(path, url)

And if you have thousands of static files, this will slow it down.

Perhaps this list could be lazy loaded on first call rather than init.

[edmorley]

Also perhaps mentioning in the documentation that it’s recommended to disabling file scanning during tests?

[cjerdonek]

I’m new to whitenoise and just saw this issue after running into it.

@evansd’s idea to store the result of walking the directory in a file occurred to me, too, and I think makes a lot of sense:

It ought to be possible to cache the entirety of WhiteNoise’s state by pickling the self.files attribute to a file somewhere,

It seems like this would be an especially good fit e.g. for people using Docker. The file could be generated as part of the Docker build and stored in the Docker image itself (or maybe generated on container startup).

I’m not sure if there’s already an open issue for this feature, but it does relate to the general issue #141 (“Make whitenoise faster”), which is still open.