[settings] Allow tests to be sped-up by preserving the test database

README.rst

@@ -294,6 +294,17 @@ Or, to generate an HTML report::
 
   $ ./bin/coverate html
 
+.. tip::
+
+   You may significatively speed-up your testing by re-using the same test
+   database from run to run. In order to do this, just specify the flag
+   ``--keepdb`` when you run your tests::
+
+     $ ./bin/django test --settings=beat.web.settings.test -v 2 --keepdb
+
+   In this case, Django will create and keep a test database called
+   ``test.sql3`` on your current directory. You may delete it when you're done.
+
 .. _snapshot:
 
 Local Development Server

beat/web/settings/test.py

@@ -36,8 +36,10 @@ ALLOWED_HOSTS = [
     'testserver',
 ]
 
-# To always use a (in-memory) sqlite3 database for the tests
-DATABASES['default'] = { 'ENGINE': 'django.db.backends.sqlite3' }
+import sys
+if '-k' in sys.argv or '--keepdb' in sys.argv:
+    # keeps the SQLite3 database around to avoid re-running migrations
+    DATABASES['default']['TEST'] = {'NAME': 'test.sql3'}
 
 PREFIX           = os.path.join(os.getcwd(), 'test_prefix')
 ALGORITHMS_ROOT  = os.path.join(PREFIX, 'algorithms')