diff --git a/mediagoblin/tests/test_migrations.py b/mediagoblin/tests/test_migrations.py
new file mode 100644
index 00000000..5d8ed02a
--- /dev/null
+++ b/mediagoblin/tests/test_migrations.py
@@ -0,0 +1,166 @@
+# GNU MediaGoblin -- federated, autonomous media hosting
+# Copyright (C) 2011 Free Software Foundation, Inc
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+from pymongo import Connection
+
+from mediagoblin.db.util import RegisterMigration, MigrationManager
+
+# This one will get filled with local migrations
+TEST_MIGRATION_REGISTRY = {}
+# this one won't get filled
+TEST_EMPTY_MIGRATION_REGISTRY = {}
+
+MIGRATION_DB_NAME = u'__mediagoblin_test_migrations__'
+
+
+######################
+# Fake test migrations
+######################
+
+@RegisterMigration(1, TEST_MIGRATION_REGISTRY)
+def creature_add_magical_powers(database):
+    """
+    Add lists of magical powers.
+
+    This defaults to [], an empty list.  Since we haven't declared any
+    magical powers, all existing monsters should 
+    """
+    pass
+
+
+@RegisterMigration(2, TEST_MIGRATION_REGISTRY)
+def creature_rename_num_legs_to_num_limbs(database):
+    """
+    It turns out we want to track how many limbs a creature has, not
+    just how many legs.  We don't care about the ambiguous distinction
+    between arms/legs currently.
+    """
+    pass
+
+
+@RegisterMigration(3, TEST_MIGRATION_REGISTRY)
+def creature_remove_is_demon(database):
+    """
+    It turns out we don't care much about whether creatures are demons
+    or not.
+    """
+    pass
+
+
+@RegisterMigration(4, TEST_MIGRATION_REGISTRY)
+def level_exits_dict_to_list(database):
+    """
+    For the sake of the indexes we want to write, and because we
+    intend to add more flexible fields, we want to move level exits
+    from like:
+
+      {'big_door': 'castle_level_id',
+       'trapdoor': 'dungeon_level_id'}
+
+    to like:
+
+      [{'name': 'big_door',
+        'exits_to': 'castle_level_id'},
+       {'name': 'trapdoor',
+        'exits_to': 'dungeon_level_id'}]
+    """
+    pass
+
+
+UNMIGRATED_DBDATA = {
+    'creatures': [
+        {'name': 'centipede',
+         'num_legs': 100,
+         'is_demon': False},
+        {'name': 'wolf',
+         'num_legs': 4,
+         'is_demon': False},
+        # don't ask me what a wizardsnake is.
+        {'name': 'wizardsnake',
+         'num_legs': 0,
+         'is_demon': True}],
+    'levels': [
+        {'_id': 'necroplex',
+         'name': 'The Necroplex',
+         'description': 'A complex full of pure deathzone.',
+         'exits': {
+                'deathwell': 'evilstorm',
+                'portal': 'central_park'}},
+        {'_id': 'evilstorm',
+         'name': 'Evil Storm',
+         'description': 'A storm full of pure evil.',
+         'exits': {}}, # you can't escape the evilstorm
+        {'_id': 'central_park',
+         'name': 'Central Park, NY, NY',
+         'description': "New York's friendly Central Park.",
+         'exits': {
+                'portal': 'necroplex'}}]}
+                    
+
+# We want to make sure that if we're at migration 3, migration 3
+# doesn't get re-run.
+
+SEMI_MIGRATED_DBDATA = {
+    'creatures': [
+        {'name': 'centipede',
+         'num_limbs': 100,
+         'magical_powers': []},
+        {'name': 'wolf',
+         'num_limbs': 4,
+         # kept around namely to check that it *isn't* removed!
+         'is_demon': False,
+         'magical_powers': [
+                'ice_breath', 'death_stare']},
+        {'name': 'wizardsnake',
+         'num_limbs': 0,
+         'magical_powers': [
+                'death_rattle', 'sneaky_stare',
+                'slithery_smoke', 'treacherous_tremors'],
+         'is_demon': True}],
+    'levels': [
+        {'_id': 'necroplex',
+         'name': 'The Necroplex',
+         'description': 'A complex full of pure deathzone.',
+         'exits': [
+                {'name': 'deathwell',
+                 'exits_to': 'evilstorm'},
+                {'name': 'portal',
+                 'exits_to': 'central_park'}]},
+        {'_id': 'evilstorm',
+         'name': 'Evil Storm',
+         'description': 'A storm full of pure evil.',
+         'exits': []}, # you can't escape the evilstorm
+        {'_id': 'central_park',
+         'name': 'Central Park, NY, NY',
+         'description': "New York's friendly Central Park.",
+         'exits': [
+                {'name': 'portal',
+                 'exits_to': 'necroplex'}]}]}
+
+
+class TestMigrations(object):
+    def setUp(self):
+        # Set up the connection, drop an existing possible database
+        self.connection = Connection()
+        self.connection.drop_database(MIGRATION_DB_NAME)
+        self.db = Connection()[MIGRATION_DB_NAME]
+        self.migration_manager = MigrationManager(
+            self.db, TEST_MIGRATION_REGISTRY)
+
+    def tearDown(self):
+        self.connection.drop_database(MIGRATION_DB_NAME)
+