Fixed #11398 - Added a pre_syncdb signal

tests/syncdb_signals/tests.py

@@ -0,0 +1,79 @@
+from django.db import connections
+from django.db.models import signals
+from django.test import TestCase
+from django.core import management
+from django.utils import six
+
+from shared_models import models
+
+
+PRE_SYNCDB_ARGS = ['app', 'create_models', 'verbosity', 'interactive', 'db']
+SYNCDB_DATABASE = 'default'
+SYNCDB_VERBOSITY = 1
+SYNCDB_INTERACTIVE = False
+
+
+class PreSyncdbReceiver(object):
+    def __init__(self):
+        self.call_counter = 0
+        self.call_args = None
+
+    def __call__(self, signal, sender, **kwargs):
+        self.call_counter = self.call_counter + 1
+        self.call_args = kwargs
+
+
+class OneTimeReceiver(object):
+    """
+    Special receiver for handle the fact that test runner calls syncdb for
+    several databases and several times for some of them.
+    """
+
+    def __init__(self):
+        self.call_counter = 0
+        self.call_args = None
+        self.tables = None  # list of tables at the time of the call
+
+    def __call__(self, signal, sender, **kwargs):
+        # Although test runner calls syncdb for several databases,
+        # testing for only one of them is quite sufficient.
+        if kwargs['db'] == SYNCDB_DATABASE:
+            self.call_counter = self.call_counter + 1
+            self.call_args = kwargs
+            connection = connections[SYNCDB_DATABASE]
+            self.tables = connection.introspection.table_names()
+            # we need to test only one call of syncdb
+            signals.pre_syncdb.disconnect(pre_syncdb_receiver, sender=models)
+
+
+# We connect receiver here and not in unit test code because we need to
+# connect receiver before test runner creates database.  That is, sequence of
+# actions would be:
+#
+#   1. Test runner imports this module.
+#   2. We connect receiver.
+#   3. Test runner calls syncdb for create default database.
+#   4. Test runner execute our unit test code.
+pre_syncdb_receiver = OneTimeReceiver()
+signals.pre_syncdb.connect(pre_syncdb_receiver, sender=models)
+
+
+class SyncdbSignalTests(TestCase):
+    def test_pre_syncdb_call_time(self):
+        self.assertEqual(pre_syncdb_receiver.call_counter, 1)
+        self.assertFalse(pre_syncdb_receiver.tables)
+
+    def test_pre_syncdb_args(self):
+        r = PreSyncdbReceiver()
+        signals.pre_syncdb.connect(r, sender=models)
+        management.call_command('syncdb', database=SYNCDB_DATABASE,
+            verbosity=SYNCDB_VERBOSITY, interactive=SYNCDB_INTERACTIVE,
+            load_initial_data=False, stdout=six.StringIO())
+
+        args = r.call_args
+        self.assertEqual(r.call_counter, 1)
+        self.assertEqual(set(args), set(PRE_SYNCDB_ARGS))
+        self.assertEqual(args['app'], models)
+        self.assertEqual(args['verbosity'], SYNCDB_VERBOSITY)
+        self.assertEqual(args['interactive'], SYNCDB_INTERACTIVE)
+        self.assertEqual(args['db'], 'default')