tracker-sandbox.py and UI tests

[Pranav Kant <pranav913 gmail com>]

I have been working on UI tests for gnome-photos. There are few things
that makes testing these content application different from others.
Testing these applications cannot be completed with just using 1 or 2
images as test data, it requires enough images, so that functionality
like adding to collections, selecting multiple images and then
deleting them etc. all can be tested. My WIP patches[1] are currently
making use of Adwaita icons as test data. It would copy few of the
Adwaita icons from /usr/share/icons/ into a tmp test directory and
insert their entry in tracker DB. However, we don't want the usual
stuff that might or might not be in the user's tracker DB to show up
during the tests.

I have been using tracker-sandbox.py[2] to keep the test data separate
from user's test data. But there is a problem here, tracker-sandbox.py
runs tracker-miner-fs and mines all the content that you want it to
mine for us; I am able to see all the image entries in tracker DB but
they are detected as application/octet-stream, not as image mimetype
which means they won't show up in gnome-photos.

Upon some investigation, it seems that `xdg-mime` is returning a wrong
mimetype for image files inside sandboxed shell. However, it returns a
valid mimetype outside tracker sandboxed shell. Here is the result of
running `tracker-extract` on one of the image files :
http://fpaste.org/169097/21161511/ from which it appears that it GIO
can't recognise the mimetype of the file.

Can you please have a look and show some pointers where I could have messed up ?


[1] https://bugzilla.gnome.org/show_bug.cgi?id=742732
[2] http://www.lanedo.com/sandboxing-your-data/
-- 
Regards,
Pranav Kant,
Department of Computer Science
National Institute of Technology Hamirpur
http://pricked.in/