WIP: Experimenting with h5py mocking

[matthewturk]

This is another WIP experiment. I have taken to heart what @Xarthisius has said for a while about how it would be nice to mock h5py.

This requires a file that can be generated, called mock_hdf5_structure.json that we can use. Here's code for generating a set of them:

https://gist.github.com/matthewturk/5313f6318d89763fd4282f49c654d500

I've also included a fake one in there. You'll need to search-and-replace the path to get it to match yours, but if you then have a .hierarchy and a parameter file next to it, you should be set. Then, interactively,

from conftest import patch_h5py
patch_h5py(None)

import yt
ds = yt.load("Whatever/galaxy0030/galaxy0030")

Right now it'll generate a field list, but I need to properly implement MockH5pyH5d.open and MockH5pyH5d.read before it'll do anything else. I'll give that a go.

This would dramatically reduce the amount of data we'd need. I think with some additional coding we could mock up some other readers, too.

[neutrinoceros]

quick note: conftest.py shouldn't be used as a module to import stuff from, please use a dedicated module for that

[matthewturk]

Fair point! The import of the mock will need to go in there eventually though, right? So that pytest can pick it up?

Where should I put it to avoid importing yt.whatever -- i.e., having the h5py mock exist outside of it?

(Also that's just in my example script, not planning on having that be used anywhere other than testing the test :) )