This will be helpful in the upcoming changes which will make use
of this extracted function to re-create zulip_test_template after
migrating zulip_test db so that we have latest schema in tests.
This is required because the --settings=zproject.test_settings param
doesn't work with migrate or the dumpdata management commands. Thus
untill now if one ran just this tool ended up with test database not
properly setup. We never noticed this because test-backend ran this
tool again (after exporting DJANGO_SETTINGS_MODULE) thus making the
tool work this time.
This should mean that maintaining two Zulip development environments
using the same Git checkout no longer has caching problems keeping
track of the migration status.
Previously, the generate-fixtures shell script by called into Django
multiple times in order to check whether the database was in a
reasonable state. Since there's a lot of overhead to starting up
Django, this resulted in `test-backend` and `test-js-with-casper`
being quite slow to run a single small test (2.8s or so) even on my
very fast laptop.
We fix this is by moving the checks into a new Python library, so that
we can avoid paying the Django startup overhead 3 times unnecessarily.
The result saves about 1.2s (~40%) from the time required to run a
single backend test.
Fixes#1221.
When running ./tools/test-backend, the script to generate
fixtures, ./tools/setup/generate-fixtures, looks for a file
called migration-status to determine whether it can short
circuit doing database migrations. This file got moved as
part of the effort to put files in "var," but the existence
check was still looking for that file in its old location.