[tests] add u1db sync tests to sqlcipher's tests

3 files changed, 633 insertions, 1258 deletions

diff --git a/common/src/leap/soledad/common/tests/test_sqlcipher_sync.py b/common/src/leap/soledad/common/tests/test_sqlcipher_sync.py
index dd66a58a..48e64d24 100644
--- a/common/src/leap/soledad/common/tests/test_sqlcipher_sync.py
+++ b/common/src/leap/soledad/common/tests/test_sqlcipher_sync.py
@@ -20,10 +20,10 @@ Test sqlcipher backend sync.
 
 
 import simplejson as json
-from u1db import (
-    sync,
-    vectorclock,
-)
+
+from u1db import sync
+from u1db import vectorclock
+from u1db import errors
 
 from testscenarios import TestWithScenarios
 from urlparse import urljoin
@@ -148,6 +148,32 @@ class SQLCipherDatabaseSyncTests(
             return
         self.assertEqual(expected, log)
 
+    def copy_database(self, db, sync_role=None):
+        # DO NOT COPY OR REUSE THIS CODE OUTSIDE TESTS: COPYING U1DB DATABASES
+        # IS THE WRONG THING TO DO, THE ONLY REASON WE DO SO HERE IS TO TEST
+        # THAT WE CORRECTLY DETECT IT HAPPENING SO THAT WE CAN RAISE ERRORS
+        # RATHER THAN CORRUPT USER DATA. USE SYNC INSTEAD, OR WE WILL SEND
+        # NINJA TO YOUR HOUSE.
+        db_copy = tests.DatabaseBaseTests.copy_database(self, db)
+        name, orig_sync_role = self._use_tracking[db]
+        self._use_tracking[db_copy] = (name + '(copy)', sync_role or
+                                       orig_sync_role)
+        return db_copy
+
+    def test_sync_tracks_db_generation_of_other(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.assertEqual(0, self.sync(self.db1, self.db2))
+        self.assertEqual(
+            (0, ''), self.db1._get_replica_gen_and_trans_id('test2'))
+        self.assertEqual(
+            (0, ''), self.db2._get_replica_gen_and_trans_id('test1'))
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [], 'last_known_gen': 0},
+                                    'return':
+                                       {'docs': [], 'last_gen': 0}})
+
     def test_sync_autoresolves(self):
         """
         Test for sync autoresolve remote.
@@ -265,6 +291,214 @@ class SQLCipherDatabaseSyncTests(
         # We use the same reasoning from the last test to suppress this one.
         pass
 
+    def test_sync_pulling_doesnt_update_other_if_changed(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc = self.db2.create_doc_from_json(tests.simple_doc)
+        # After the local side has sent its list of docs, before we start
+        # receiving the "targets" response, we update the local database with a
+        # new record.
+        # When we finish synchronizing, we can notice that something locally
+        # was updated, and we cannot tell c2 our new updated generation
+
+        def before_get_docs(state):
+            if state != 'before get_docs':
+                return
+            self.db1.create_doc_from_json(tests.simple_doc)
+
+        self.assertEqual(0, self.sync(self.db1, self.db2,
+                                      trace_hook=before_get_docs))
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [], 'last_known_gen': 0},
+                                    'return':
+                                       {'docs': [(doc.doc_id, doc.rev)],
+                                        'last_gen': 1}})
+        self.assertEqual(1, self.db1._get_replica_gen_and_trans_id('test2')[0])
+        # c2 should not have gotten a '_record_sync_info' call, because the
+        # local database had been updated more than just by the messages
+        # returned from c2.
+        self.assertEqual(
+            (0, ''), self.db2._get_replica_gen_and_trans_id('test1'))
+
+    def test_sync_doesnt_update_other_if_nothing_pulled(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc)
+
+        def no_record_sync_info(state):
+            if state != 'record_sync_info':
+                return
+            self.fail('SyncTarget.record_sync_info was called')
+        self.assertEqual(1, self.sync(self.db1, self.db2,
+                                      trace_hook_shallow=no_record_sync_info))
+        self.assertEqual(
+            1,
+            self.db2._get_replica_gen_and_trans_id(self.db1._replica_uid)[0])
+
+    def test_sync_ignores_convergence(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'both')
+        doc = self.db1.create_doc_from_json(tests.simple_doc)
+        self.db3 = self.create_database('test3', 'target')
+        self.assertEqual(1, self.sync(self.db1, self.db3))
+        self.assertEqual(0, self.sync(self.db2, self.db3))
+        self.assertEqual(1, self.sync(self.db1, self.db2))
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [(doc.doc_id, doc.rev)],
+                                        'source_uid': 'test1',
+                                        'source_gen': 1, 'last_known_gen': 0},
+                                    'return': {'docs': [], 'last_gen': 1}})
+
+    def test_sync_ignores_superseded(self):
+        self.db1 = self.create_database('test1', 'both')
+        self.db2 = self.create_database('test2', 'both')
+        doc = self.db1.create_doc_from_json(tests.simple_doc)
+        doc_rev1 = doc.rev
+        self.db3 = self.create_database('test3', 'target')
+        self.sync(self.db1, self.db3)
+        self.sync(self.db2, self.db3)
+        new_content = '{"key": "altval"}'
+        doc.set_json(new_content)
+        self.db1.put_doc(doc)
+        doc_rev2 = doc.rev
+        self.sync(self.db2, self.db1)
+        self.assertLastExchangeLog(self.db1,
+                                   {'receive':
+                                       {'docs': [(doc.doc_id, doc_rev1)],
+                                        'source_uid': 'test2',
+                                        'source_gen': 1, 'last_known_gen': 0},
+                                    'return':
+                                       {'docs': [(doc.doc_id, doc_rev2)],
+                                        'last_gen': 2}})
+        self.assertGetDoc(self.db1, doc.doc_id, doc_rev2, new_content, False)
+
+    def test_sync_sees_remote_conflicted(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc1 = self.db1.create_doc_from_json(tests.simple_doc)
+        doc_id = doc1.doc_id
+        doc1_rev = doc1.rev
+        self.db1.create_index('test-idx', 'key')
+        new_doc = '{"key": "altval"}'
+        doc2 = self.db2.create_doc_from_json(new_doc, doc_id=doc_id)
+        doc2_rev = doc2.rev
+        self.assertTransactionLog([doc1.doc_id], self.db1)
+        self.sync(self.db1, self.db2)
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [(doc_id, doc1_rev)],
+                                        'source_uid': 'test1',
+                                        'source_gen': 1, 'last_known_gen': 0},
+                                    'return':
+                                       {'docs': [(doc_id, doc2_rev)],
+                                        'last_gen': 1}})
+        self.assertTransactionLog([doc_id, doc_id], self.db1)
+        self.assertGetDoc(self.db1, doc_id, doc2_rev, new_doc, True)
+        self.assertGetDoc(self.db2, doc_id, doc2_rev, new_doc, False)
+        from_idx = self.db1.get_from_index('test-idx', 'altval')[0]
+        self.assertEqual(doc2.doc_id, from_idx.doc_id)
+        self.assertEqual(doc2.rev, from_idx.rev)
+        self.assertTrue(from_idx.has_conflicts)
+        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
+
+    def test_sync_sees_remote_delete_conflicted(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc1 = self.db1.create_doc_from_json(tests.simple_doc)
+        doc_id = doc1.doc_id
+        self.db1.create_index('test-idx', 'key')
+        self.sync(self.db1, self.db2)
+        doc2 = self.make_document(doc1.doc_id, doc1.rev, doc1.get_json())
+        new_doc = '{"key": "altval"}'
+        doc1.set_json(new_doc)
+        self.db1.put_doc(doc1)
+        self.db2.delete_doc(doc2)
+        self.assertTransactionLog([doc_id, doc_id], self.db1)
+        self.sync(self.db1, self.db2)
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [(doc_id, doc1.rev)],
+                                        'source_uid': 'test1',
+                                        'source_gen': 2, 'last_known_gen': 1},
+                                    'return': {'docs': [(doc_id, doc2.rev)],
+                                               'last_gen': 2}})
+        self.assertTransactionLog([doc_id, doc_id, doc_id], self.db1)
+        self.assertGetDocIncludeDeleted(self.db1, doc_id, doc2.rev, None, True)
+        self.assertGetDocIncludeDeleted(
+            self.db2, doc_id, doc2.rev, None, False)
+        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
+
+    def test_sync_local_race_conflicted(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc = self.db1.create_doc_from_json(tests.simple_doc)
+        doc_id = doc.doc_id
+        doc1_rev = doc.rev
+        self.db1.create_index('test-idx', 'key')
+        self.sync(self.db1, self.db2)
+        content1 = '{"key": "localval"}'
+        content2 = '{"key": "altval"}'
+        doc.set_json(content2)
+        self.db2.put_doc(doc)
+        doc2_rev2 = doc.rev
+        triggered = []
+
+        def after_whatschanged(state):
+            if state != 'after whats_changed':
+                return
+            triggered.append(True)
+            doc = self.make_document(doc_id, doc1_rev, content1)
+            self.db1.put_doc(doc)
+
+        self.sync(self.db1, self.db2, trace_hook=after_whatschanged)
+        self.assertEqual([True], triggered)
+        self.assertGetDoc(self.db1, doc_id, doc2_rev2, content2, True)
+        from_idx = self.db1.get_from_index('test-idx', 'altval')[0]
+        self.assertEqual(doc.doc_id, from_idx.doc_id)
+        self.assertEqual(doc.rev, from_idx.rev)
+        self.assertTrue(from_idx.has_conflicts)
+        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
+        self.assertEqual([], self.db1.get_from_index('test-idx', 'localval'))
+
+    def test_sync_propagates_deletes(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'both')
+        doc1 = self.db1.create_doc_from_json(tests.simple_doc)
+        doc_id = doc1.doc_id
+        self.db1.create_index('test-idx', 'key')
+        self.sync(self.db1, self.db2)
+        self.db2.create_index('test-idx', 'key')
+        self.db3 = self.create_database('test3', 'target')
+        self.sync(self.db1, self.db3)
+        self.db1.delete_doc(doc1)
+        deleted_rev = doc1.rev
+        self.sync(self.db1, self.db2)
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [(doc_id, deleted_rev)],
+                                        'source_uid': 'test1',
+                                        'source_gen': 2, 'last_known_gen': 1},
+                                    'return': {'docs': [], 'last_gen': 2}})
+        self.assertGetDocIncludeDeleted(
+            self.db1, doc_id, deleted_rev, None, False)
+        self.assertGetDocIncludeDeleted(
+            self.db2, doc_id, deleted_rev, None, False)
+        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
+        self.assertEqual([], self.db2.get_from_index('test-idx', 'value'))
+        self.sync(self.db2, self.db3)
+        self.assertLastExchangeLog(self.db3,
+                                   {'receive':
+                                       {'docs': [(doc_id, deleted_rev)],
+                                        'source_uid': 'test2',
+                                        'source_gen': 2,
+                                        'last_known_gen': 0},
+                                    'return':
+                                       {'docs': [], 'last_gen': 2}})
+        self.assertGetDocIncludeDeleted(
+            self.db3, doc_id, deleted_rev, None, False)
+
     def test_sync_propagates_resolution(self):
         """
         Test if synchronization propagates resolution.
@@ -340,6 +574,132 @@ class SQLCipherDatabaseSyncTests(
                          'source_gen': 1, 'last_known_gen': 0},
              'return': {'docs': [], 'last_gen': 1}})
 
+    def test_sync_pulls_changes(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        doc = self.db2.create_doc_from_json(tests.simple_doc)
+        self.db1.create_index('test-idx', 'key')
+        self.assertEqual(0, self.sync(self.db1, self.db2))
+        self.assertGetDoc(self.db1, doc.doc_id, doc.rev, tests.simple_doc, False)
+        self.assertEqual(1, self.db1._get_replica_gen_and_trans_id('test2')[0])
+        self.assertEqual(1, self.db2._get_replica_gen_and_trans_id('test1')[0])
+        self.assertLastExchangeLog(self.db2,
+                                   {'receive':
+                                       {'docs': [], 'last_known_gen': 0},
+                                    'return':
+                                       {'docs': [(doc.doc_id, doc.rev)],
+                                        'last_gen': 1}})
+        self.assertEqual([doc], self.db1.get_from_index('test-idx', 'value'))
+
+    def test_sync_supersedes_conflicts(self):
+        self.db1 = self.create_database('test1', 'both')
+        self.db2 = self.create_database('test2', 'target')
+        self.db3 = self.create_database('test3', 'both')
+        doc1 = self.db1.create_doc_from_json('{"a": 1}', doc_id='the-doc')
+        self.db2.create_doc_from_json('{"b": 1}', doc_id='the-doc')
+        self.db3.create_doc_from_json('{"c": 1}', doc_id='the-doc')
+        self.sync(self.db3, self.db1)
+        self.assertEqual(
+            self.db1._get_generation_info(),
+            self.db3._get_replica_gen_and_trans_id(self.db1._replica_uid))
+        self.assertEqual(
+            self.db3._get_generation_info(),
+            self.db1._get_replica_gen_and_trans_id(self.db3._replica_uid))
+        self.sync(self.db3, self.db2)
+        self.assertEqual(
+            self.db2._get_generation_info(),
+            self.db3._get_replica_gen_and_trans_id(self.db2._replica_uid))
+        self.assertEqual(
+            self.db3._get_generation_info(),
+            self.db2._get_replica_gen_and_trans_id(self.db3._replica_uid))
+        self.assertEqual(3, len(self.db3.get_doc_conflicts('the-doc')))
+        doc1.set_json('{"a": 2}')
+        self.db1.put_doc(doc1)
+        self.sync(self.db3, self.db1)
+        # original doc1 should have been removed from conflicts
+        self.assertEqual(3, len(self.db3.get_doc_conflicts('the-doc')))
+
+    def test_sync_stops_after_get_sync_info(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc)
+        self.sync(self.db1, self.db2)
+
+        def put_hook(state):
+            self.fail("Tracehook triggered for %s" % (state,))
+
+        self.sync(self.db1, self.db2, trace_hook_shallow=put_hook)
+
+    def test_sync_detects_rollback_in_source(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc1')
+        self.sync(self.db1, self.db2)
+        self.db1_copy = self.copy_database(self.db1)
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc2')
+        self.sync(self.db1, self.db2)
+        self.assertRaises(
+            errors.InvalidGeneration, self.sync, self.db1_copy, self.db2)
+
+    def test_sync_detects_rollback_in_target(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
+        self.sync(self.db1, self.db2)
+        self.db2_copy = self.copy_database(self.db2)
+        self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc2')
+        self.sync(self.db1, self.db2)
+        self.assertRaises(
+            errors.InvalidGeneration, self.sync, self.db1, self.db2_copy)
+
+    def test_sync_detects_diverged_source(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db3 = self.copy_database(self.db1)
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
+        self.db3.create_doc_from_json(tests.simple_doc, doc_id="divergent")
+        self.sync(self.db1, self.db2)
+        self.assertRaises(
+            errors.InvalidTransactionId, self.sync, self.db3, self.db2)
+
+    def test_sync_detects_diverged_target(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db3 = self.copy_database(self.db2)
+        self.db3.create_doc_from_json(tests.nested_doc, doc_id="divergent")
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
+        self.sync(self.db1, self.db2)
+        self.assertRaises(
+            errors.InvalidTransactionId, self.sync, self.db1, self.db3)
+
+    def test_sync_detects_rollback_and_divergence_in_source(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc1')
+        self.sync(self.db1, self.db2)
+        self.db1_copy = self.copy_database(self.db1)
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc2')
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc3')
+        self.sync(self.db1, self.db2)
+        self.db1_copy.create_doc_from_json(tests.simple_doc, doc_id='doc2')
+        self.db1_copy.create_doc_from_json(tests.simple_doc, doc_id='doc3')
+        self.assertRaises(
+            errors.InvalidTransactionId, self.sync, self.db1_copy, self.db2)
+
+    def test_sync_detects_rollback_and_divergence_in_target(self):
+        self.db1 = self.create_database('test1', 'source')
+        self.db2 = self.create_database('test2', 'target')
+        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
+        self.sync(self.db1, self.db2)
+        self.db2_copy = self.copy_database(self.db2)
+        self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc2')
+        self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc3')
+        self.sync(self.db1, self.db2)
+        self.db2_copy.create_doc_from_json(tests.simple_doc, doc_id='doc2')
+        self.db2_copy.create_doc_from_json(tests.simple_doc, doc_id='doc3')
+        self.assertRaises(
+            errors.InvalidTransactionId, self.sync, self.db1, self.db2_copy)
+
 
 def _make_local_db_and_token_http_target(test, path='test'):
     test.startTwistedServer()
@@ -347,6 +707,7 @@ def _make_local_db_and_token_http_target(test, path='test'):
     db = couch.CouchDatabase.open_database(
         urljoin(test._couch_url, 'test'),
         create=True,
+        replica_uid='test',
         ensure_ddocs=True)
 
     replica_uid = test._soledad._dbpool.replica_uid
@@ -373,6 +734,9 @@ class SQLCipherSyncTargetTests(
         tests.TestCaseWithServer,
         SoledadWithCouchServerMixin):
 
+    # TODO: implement _set_trace_hook(_shallow) in SoledadHTTPSyncTarget so
+    #       skipped tests can be succesfully executed.
+
     scenarios = (tests.multiply_scenarios(SQLCIPHER_SCENARIOS,
                                           target_scenarios))
 
@@ -401,6 +765,41 @@ class SQLCipherSyncTargetTests(
         self.request_state = couch.CouchServerState(self._couch_url)
         return self.make_app_with_state(self.request_state)
 
+    def set_trace_hook(self, callback, shallow=False):
+        setter = (self.st._set_trace_hook if not shallow else
+                  self.st._set_trace_hook_shallow)
+        try:
+            setter(callback)
+        except NotImplementedError:
+            self.skipTest("%s does not implement _set_trace_hook"
+                          % (self.st.__class__.__name__,))
+
+    def test_get_sync_target(self):
+        self.assertIsNot(None, self.st)
+
+    @defer.inlineCallbacks
+    def test_get_sync_info(self):
+        sync_info = yield self.st.get_sync_info('other')
+        self.assertEqual(
+            ('test', 0, '', 0, ''), sync_info)
+
+    @defer.inlineCallbacks
+    def test_create_doc_updates_sync_info(self):
+        sync_info = yield self.st.get_sync_info('other')
+        self.assertEqual(
+            ('test', 0, '', 0, ''), sync_info)
+        self.db.create_doc_from_json(tests.simple_doc)
+        sync_info = yield self.st.get_sync_info('other')
+        self.assertEqual(1, sync_info[1])
+
+    @defer.inlineCallbacks
+    def test_record_sync_info(self):
+        yield self.st.record_sync_info('replica', 10, 'T-transid')
+        sync_info = yield self.st.get_sync_info('other')
+        self.assertEqual(
+            ('test', 0, '', 10, 'T-transid'), sync_info)
+
+
     @defer.inlineCallbacks
     def test_sync_exchange(self):
         """
@@ -476,3 +875,231 @@ class SQLCipherSyncTargetTests(
                 self.db._last_exchange_log['return'],
                 {'last_gen': 2, 'docs':
                  [(doc.doc_id, doc.rev), (doc2.doc_id, doc2.rev)]})
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_deleted(self):
+        doc = self.db.create_doc_from_json('{}')
+        edit_rev = 'replica:1|' + doc.rev
+        docs_by_gen = [
+            (self.make_document(doc.doc_id, edit_rev, None), 10, 'T-sid')]
+        new_gen, trans_id = yield self.st.sync_exchange(
+            docs_by_gen, 'replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertGetDocIncludeDeleted(
+            self.db, doc.doc_id, edit_rev, None, False)
+        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
+        last_trans_id = self.getLastTransId(self.db)
+        self.assertEqual(([], 2, last_trans_id),
+                         (self.other_changes, new_gen, trans_id))
+        sync_info = yield self.st.get_sync_info('replica')
+        self.assertEqual(10, sync_info[3])
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_refuses_conflicts(self):
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        new_doc = '{"key": "altval"}'
+        docs_by_gen = [
+            (self.make_document(doc.doc_id, 'replica:1', new_doc), 10,
+             'T-sid')]
+        new_gen, _ = yield self.st.sync_exchange(
+            docs_by_gen, 'replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        self.assertEqual(
+            (doc.doc_id, doc.rev, tests.simple_doc, 1), self.other_changes[0][:-1])
+        self.assertEqual(1, new_gen)
+        if self.whitebox:
+            self.assertEqual(self.db._last_exchange_log['return'],
+                             {'last_gen': 1, 'docs': [(doc.doc_id, doc.rev)]})
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_ignores_convergence(self):
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        gen, txid = self.db._get_generation_info()
+        docs_by_gen = [
+            (self.make_document(doc.doc_id, doc.rev, tests.simple_doc), 10, 'T-sid')]
+        new_gen, _ = yield self.st.sync_exchange(
+            docs_by_gen, 'replica', last_known_generation=gen,
+            last_known_trans_id=txid, insert_doc_cb=self.receive_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        self.assertEqual(([], 1), (self.other_changes, new_gen))
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_returns_new_docs(self):
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        new_gen, _ = yield self.st.sync_exchange(
+            [], 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        self.assertEqual(
+            (doc.doc_id, doc.rev, tests.simple_doc, 1), self.other_changes[0][:-1])
+        self.assertEqual(1, new_gen)
+        if self.whitebox:
+            self.assertEqual(self.db._last_exchange_log['return'],
+                             {'last_gen': 1, 'docs': [(doc.doc_id, doc.rev)]})
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_returns_deleted_docs(self):
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.db.delete_doc(doc)
+        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
+        new_gen, _ = yield self.st.sync_exchange(
+            [], 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
+        self.assertEqual(
+            (doc.doc_id, doc.rev, None, 2), self.other_changes[0][:-1])
+        self.assertEqual(2, new_gen)
+        if self.whitebox:
+            self.assertEqual(self.db._last_exchange_log['return'],
+                             {'last_gen': 2, 'docs': [(doc.doc_id, doc.rev)]})
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_getting_newer_docs(self):
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        new_doc = '{"key": "altval"}'
+        docs_by_gen = [
+            (self.make_document(doc.doc_id, 'test:1|z:2', new_doc), 10,
+             'T-sid')]
+        new_gen, _ = yield self.st.sync_exchange(
+            docs_by_gen, 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
+        self.assertEqual(([], 2), (self.other_changes, new_gen))
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_with_concurrent_updates_of_synced_doc(self):
+        expected = []
+
+        def before_whatschanged_cb(state):
+            if state != 'before whats_changed':
+                return
+            cont = '{"key": "cuncurrent"}'
+            conc_rev = self.db.put_doc(
+                self.make_document(doc.doc_id, 'test:1|z:2', cont))
+            expected.append((doc.doc_id, conc_rev, cont, 3))
+
+        self.set_trace_hook(before_whatschanged_cb)
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        new_doc = '{"key": "altval"}'
+        docs_by_gen = [
+            (self.make_document(doc.doc_id, 'test:1|z:2', new_doc), 10,
+             'T-sid')]
+        new_gen, _ = yield self.st.sync_exchange(
+            docs_by_gen, 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertEqual(expected, [c[:-1] for c in self.other_changes])
+        self.assertEqual(3, new_gen)
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_with_concurrent_updates(self):
+
+        def after_whatschanged_cb(state):
+            if state != 'after whats_changed':
+                return
+            self.db.create_doc_from_json('{"new": "doc"}')
+
+        self.set_trace_hook(after_whatschanged_cb)
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        new_doc = '{"key": "altval"}'
+        docs_by_gen = [
+            (self.make_document(doc.doc_id, 'test:1|z:2', new_doc), 10,
+             'T-sid')]
+        new_gen, _ = yield self.st.sync_exchange(
+            docs_by_gen, 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertEqual(([], 2), (self.other_changes, new_gen))
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_converged_handling(self):
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        docs_by_gen = [
+            (self.make_document('new', 'other:1', '{}'), 4, 'T-foo'),
+            (self.make_document(doc.doc_id, doc.rev, doc.get_json()), 5,
+             'T-bar')]
+        new_gen, _ = yield self.st.sync_exchange(
+            docs_by_gen, 'other-replica', last_known_generation=0,
+            last_known_trans_id=None, insert_doc_cb=self.receive_doc)
+        self.assertEqual(([], 2), (self.other_changes, new_gen))
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_detect_incomplete_exchange(self):
+        def before_get_docs_explode(state):
+            if state != 'before get_docs':
+                return
+            raise errors.U1DBError("fail")
+        self.set_trace_hook(before_get_docs_explode)
+        # suppress traceback printing in the wsgiref server
+        #self.patch(simple_server.ServerHandler,
+        #           'log_exception', lambda h, exc_info: None)
+        doc = self.db.create_doc_from_json(tests.simple_doc)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        with self.assertRaises((errors.U1DBError, errors.BrokenSyncStream)):
+            yield self.st.sync_exchange(
+                [], 'other-replica',
+                last_known_generation=0, last_known_trans_id=None,
+                insert_doc_cb=self.receive_doc)
+
+    @defer.inlineCallbacks
+    def test_sync_exchange_doc_ids(self):
+        sync_exchange_doc_ids = getattr(self.st, 'sync_exchange_doc_ids', None)
+        if sync_exchange_doc_ids is None:
+            self.skipTest("sync_exchange_doc_ids not implemented")
+        db2 = self.create_database('test2')
+        doc = db2.create_doc_from_json(tests.simple_doc)
+        new_gen, trans_id = sync_exchange_doc_ids(
+            db2, [(doc.doc_id, 10, 'T-sid')], 0, None,
+            insert_doc_cb=self.receive_doc)
+        self.assertGetDoc(self.db, doc.doc_id, doc.rev, tests.simple_doc, False)
+        self.assertTransactionLog([doc.doc_id], self.db)
+        last_trans_id = self.getLastTransId(self.db)
+        self.assertEqual(([], 1, last_trans_id),
+                         (self.other_changes, new_gen, trans_id))
+        self.assertEqual(10, self.st.get_sync_info(db2._replica_uid)[3])
+
+    @defer.inlineCallbacks
+    def test__set_trace_hook(self):
+        called = []
+
+        def cb(state):
+            called.append(state)
+
+        self.set_trace_hook(cb)
+        yield self.st.sync_exchange([], 'replica', 0, None, self.receive_doc)
+        yield self.st.record_sync_info('replica', 0, 'T-sid')
+        self.assertEqual(['before whats_changed',
+                          'after whats_changed',
+                          'before get_docs',
+                          'record_sync_info',
+                          ],
+                         called)
+
+    @defer.inlineCallbacks
+    def test__set_trace_hook_shallow(self):
+        if (self.st._set_trace_hook_shallow == self.st._set_trace_hook or
+            self.st._set_trace_hook_shallow.im_func ==
+                SoledadHTTPSyncTarget._set_trace_hook_shallow.im_func):
+            # shallow same as full
+            expected = ['before whats_changed',
+                        'after whats_changed',
+                        'before get_docs',
+                        'record_sync_info',
+                        ]
+        else:
+            expected = ['sync_exchange', 'record_sync_info']
+
+        called = []
+
+        def cb(state):
+            called.append(state)
+
+        self.set_trace_hook(cb, shallow=True)
+        self.st.sync_exchange([], 'replica', 0, None, self.receive_doc)
+        self.st.record_sync_info('replica', 0, 'T-sid')
+        self.assertEqual(expected, called)
diff --git a/common/src/leap/soledad/common/tests/test_sync.py b/common/src/leap/soledad/common/tests/test_sync.py
index 9638ec1a..14152370 100644
--- a/common/src/leap/soledad/common/tests/test_sync.py
+++ b/common/src/leap/soledad/common/tests/test_sync.py
@@ -226,3 +226,5 @@ class TestSoledadDbSync(
             self.db2, doc1.doc_id, doc1.rev, tests.simple_doc, False)
         self.assertGetEncryptedDoc(
             self.db, doc2.doc_id, doc2.rev, tests.nested_doc, False)
+
+    # TODO: add u1db.tests.test_sync.TestRemoteSyncIntegration
diff --git a/common/src/leap/soledad/common/tests/u1db_tests/test_sync.py b/common/src/leap/soledad/common/tests/u1db_tests/test_sync.py
deleted file mode 100644
index a7b05c9a..00000000
--- a/common/src/leap/soledad/common/tests/u1db_tests/test_sync.py
+++ /dev/null
@@ -1,1254 +0,0 @@
-# Copyright 2011-2012 Canonical Ltd.
-#
-# This file is part of u1db.
-#
-# u1db is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Lesser General Public License version 3
-# as published by the Free Software Foundation.
-#
-# u1db 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 Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public License
-# along with u1db.  If not, see <http://www.gnu.org/licenses/>.
-
-"""The Synchronization class for U1DB."""
-
-import os
-from wsgiref import simple_server
-
-from u1db import (
-    errors,
-    sync,
-    vectorclock,
-    SyncTarget,
-)
-
-from unittest import skip
-
-from leap.soledad.common.tests import u1db_tests as tests
-
-from u1db.backends import (
-    inmemory,
-)
-from u1db.remote import (
-    http_target,
-)
-
-from leap.soledad.common.tests.u1db_tests.test_remote_sync_target import (
-    make_http_app,
-    make_oauth_http_app,
-)
-
-simple_doc = tests.simple_doc
-nested_doc = tests.nested_doc
-
-
-def _make_local_db_and_target(test):
-    db = test.create_database('test')
-    st = db.get_sync_target()
-    return db, st
-
-
-def _make_local_db_and_http_target(test, path='test'):
-    test.startServer()
-    db = test.request_state._create_database(os.path.basename(path))
-    st = http_target.HTTPSyncTarget.connect(test.getURL(path))
-    return db, st
-
-
-def _make_local_db_and_oauth_http_target(test):
-    db, st = _make_local_db_and_http_target(test, '~/test')
-    st.set_oauth_credentials(tests.consumer1.key, tests.consumer1.secret,
-                             tests.token1.key, tests.token1.secret)
-    return db, st
-
-
-target_scenarios = [
-    ('local', {'create_db_and_target': _make_local_db_and_target}),
-    ('http', {'create_db_and_target': _make_local_db_and_http_target,
-              'make_app_with_state': make_http_app}),
-    ('oauth_http', {'create_db_and_target':
-                    _make_local_db_and_oauth_http_target,
-                    'make_app_with_state': make_oauth_http_app}),
-]
-
-
-@skip("Skiping tests imported from U1DB.")
-class DatabaseSyncTargetTests(tests.DatabaseBaseTests,
-                              tests.TestCaseWithServer):
-
-    scenarios = (tests.multiply_scenarios(tests.DatabaseBaseTests.scenarios,
-                                          target_scenarios))
-    # + c_db_scenarios)
-    # whitebox true means self.db is the actual local db object
-    # against which the sync is performed
-    whitebox = True
-
-    def setUp(self):
-        tests.TestCaseWithServer.setUp(self)
-        self.db, self.st = self.create_db_and_target(self)
-        self.other_changes = []
-
-    def tearDown(self):
-        # We delete them explicitly, so that connections are cleanly closed
-        del self.st
-        self.db.close()
-        super(DatabaseSyncTargetTests, self).tearDown()
-
-    def create_db_and_target(self, *args):
-        return _make_local_db_and_target(*args)
-
-    def receive_doc(self, doc, gen, trans_id):
-        self.other_changes.append(
-            (doc.doc_id, doc.rev, doc.get_json(), gen, trans_id))
-
-    def set_trace_hook(self, callback, shallow=False):
-        setter = (self.st._set_trace_hook if not shallow else
-                  self.st._set_trace_hook_shallow)
-        try:
-            setter(callback)
-        except NotImplementedError:
-            self.skipTest("%s does not implement _set_trace_hook"
-                          % (self.st.__class__.__name__,))
-
-    def test_get_sync_target(self):
-        self.assertIsNot(None, self.st)
-
-    def test_get_sync_info(self):
-        self.assertEqual(
-            ('test', 0, '', 0, ''), self.st.get_sync_info('other'))
-
-    def test_create_doc_updates_sync_info(self):
-        self.assertEqual(
-            ('test', 0, '', 0, ''), self.st.get_sync_info('other'))
-        self.db.create_doc_from_json(simple_doc)
-        self.assertEqual(1, self.st.get_sync_info('other')[1])
-
-    def test_record_sync_info(self):
-        self.st.record_sync_info('replica', 10, 'T-transid')
-        self.assertEqual(
-            ('test', 0, '', 10, 'T-transid'), self.st.get_sync_info('replica'))
-
-    def test_sync_exchange(self):
-        docs_by_gen = [
-            (self.make_document('doc-id', 'replica:1', simple_doc), 10,
-             'T-sid')]
-        new_gen, trans_id = self.st.sync_exchange(
-            docs_by_gen, 'replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertGetDoc(self.db, 'doc-id', 'replica:1', simple_doc, False)
-        self.assertTransactionLog(['doc-id'], self.db)
-        last_trans_id = self.getLastTransId(self.db)
-        self.assertEqual(([], 1, last_trans_id),
-                         (self.other_changes, new_gen, last_trans_id))
-        self.assertEqual(10, self.st.get_sync_info('replica')[3])
-
-    def test_sync_exchange_deleted(self):
-        doc = self.db.create_doc_from_json('{}')
-        edit_rev = 'replica:1|' + doc.rev
-        docs_by_gen = [
-            (self.make_document(doc.doc_id, edit_rev, None), 10, 'T-sid')]
-        new_gen, trans_id = self.st.sync_exchange(
-            docs_by_gen, 'replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertGetDocIncludeDeleted(
-            self.db, doc.doc_id, edit_rev, None, False)
-        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
-        last_trans_id = self.getLastTransId(self.db)
-        self.assertEqual(([], 2, last_trans_id),
-                         (self.other_changes, new_gen, trans_id))
-        self.assertEqual(10, self.st.get_sync_info('replica')[3])
-
-    def test_sync_exchange_push_many(self):
-        docs_by_gen = [
-            (self.make_document('doc-id', 'replica:1', simple_doc), 10, 'T-1'),
-            (self.make_document('doc-id2', 'replica:1', nested_doc), 11,
-             'T-2')]
-        new_gen, trans_id = self.st.sync_exchange(
-            docs_by_gen, 'replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertGetDoc(self.db, 'doc-id', 'replica:1', simple_doc, False)
-        self.assertGetDoc(self.db, 'doc-id2', 'replica:1', nested_doc, False)
-        self.assertTransactionLog(['doc-id', 'doc-id2'], self.db)
-        last_trans_id = self.getLastTransId(self.db)
-        self.assertEqual(([], 2, last_trans_id),
-                         (self.other_changes, new_gen, trans_id))
-        self.assertEqual(11, self.st.get_sync_info('replica')[3])
-
-    def test_sync_exchange_refuses_conflicts(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        new_doc = '{"key": "altval"}'
-        docs_by_gen = [
-            (self.make_document(doc.doc_id, 'replica:1', new_doc), 10,
-             'T-sid')]
-        new_gen, _ = self.st.sync_exchange(
-            docs_by_gen, 'replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        self.assertEqual(
-            (doc.doc_id, doc.rev, simple_doc, 1), self.other_changes[0][:-1])
-        self.assertEqual(1, new_gen)
-        if self.whitebox:
-            self.assertEqual(self.db._last_exchange_log['return'],
-                             {'last_gen': 1, 'docs': [(doc.doc_id, doc.rev)]})
-
-    def test_sync_exchange_ignores_convergence(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        gen, txid = self.db._get_generation_info()
-        docs_by_gen = [
-            (self.make_document(doc.doc_id, doc.rev, simple_doc), 10, 'T-sid')]
-        new_gen, _ = self.st.sync_exchange(
-            docs_by_gen, 'replica', last_known_generation=gen,
-            last_known_trans_id=txid, return_doc_cb=self.receive_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        self.assertEqual(([], 1), (self.other_changes, new_gen))
-
-    def test_sync_exchange_returns_new_docs(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        new_gen, _ = self.st.sync_exchange(
-            [], 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        self.assertEqual(
-            (doc.doc_id, doc.rev, simple_doc, 1), self.other_changes[0][:-1])
-        self.assertEqual(1, new_gen)
-        if self.whitebox:
-            self.assertEqual(self.db._last_exchange_log['return'],
-                             {'last_gen': 1, 'docs': [(doc.doc_id, doc.rev)]})
-
-    def test_sync_exchange_returns_deleted_docs(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.db.delete_doc(doc)
-        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
-        new_gen, _ = self.st.sync_exchange(
-            [], 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
-        self.assertEqual(
-            (doc.doc_id, doc.rev, None, 2), self.other_changes[0][:-1])
-        self.assertEqual(2, new_gen)
-        if self.whitebox:
-            self.assertEqual(self.db._last_exchange_log['return'],
-                             {'last_gen': 2, 'docs': [(doc.doc_id, doc.rev)]})
-
-    def test_sync_exchange_returns_many_new_docs(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        doc2 = self.db.create_doc_from_json(nested_doc)
-        self.assertTransactionLog([doc.doc_id, doc2.doc_id], self.db)
-        new_gen, _ = self.st.sync_exchange(
-            [], 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertTransactionLog([doc.doc_id, doc2.doc_id], self.db)
-        self.assertEqual(2, new_gen)
-        self.assertEqual(
-            [(doc.doc_id, doc.rev, simple_doc, 1),
-             (doc2.doc_id, doc2.rev, nested_doc, 2)],
-            [c[:-1] for c in self.other_changes])
-        if self.whitebox:
-            self.assertEqual(
-                self.db._last_exchange_log['return'],
-                {'last_gen': 2, 'docs':
-                 [(doc.doc_id, doc.rev), (doc2.doc_id, doc2.rev)]})
-
-    def test_sync_exchange_getting_newer_docs(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        new_doc = '{"key": "altval"}'
-        docs_by_gen = [
-            (self.make_document(doc.doc_id, 'test:1|z:2', new_doc), 10,
-             'T-sid')]
-        new_gen, _ = self.st.sync_exchange(
-            docs_by_gen, 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertTransactionLog([doc.doc_id, doc.doc_id], self.db)
-        self.assertEqual(([], 2), (self.other_changes, new_gen))
-
-    def test_sync_exchange_with_concurrent_updates_of_synced_doc(self):
-        expected = []
-
-        def before_whatschanged_cb(state):
-            if state != 'before whats_changed':
-                return
-            cont = '{"key": "cuncurrent"}'
-            conc_rev = self.db.put_doc(
-                self.make_document(doc.doc_id, 'test:1|z:2', cont))
-            expected.append((doc.doc_id, conc_rev, cont, 3))
-
-        self.set_trace_hook(before_whatschanged_cb)
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        new_doc = '{"key": "altval"}'
-        docs_by_gen = [
-            (self.make_document(doc.doc_id, 'test:1|z:2', new_doc), 10,
-             'T-sid')]
-        new_gen, _ = self.st.sync_exchange(
-            docs_by_gen, 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertEqual(expected, [c[:-1] for c in self.other_changes])
-        self.assertEqual(3, new_gen)
-
-    def test_sync_exchange_with_concurrent_updates(self):
-
-        def after_whatschanged_cb(state):
-            if state != 'after whats_changed':
-                return
-            self.db.create_doc_from_json('{"new": "doc"}')
-
-        self.set_trace_hook(after_whatschanged_cb)
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        new_doc = '{"key": "altval"}'
-        docs_by_gen = [
-            (self.make_document(doc.doc_id, 'test:1|z:2', new_doc), 10,
-             'T-sid')]
-        new_gen, _ = self.st.sync_exchange(
-            docs_by_gen, 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertEqual(([], 2), (self.other_changes, new_gen))
-
-    def test_sync_exchange_converged_handling(self):
-        doc = self.db.create_doc_from_json(simple_doc)
-        docs_by_gen = [
-            (self.make_document('new', 'other:1', '{}'), 4, 'T-foo'),
-            (self.make_document(doc.doc_id, doc.rev, doc.get_json()), 5,
-             'T-bar')]
-        new_gen, _ = self.st.sync_exchange(
-            docs_by_gen, 'other-replica', last_known_generation=0,
-            last_known_trans_id=None, return_doc_cb=self.receive_doc)
-        self.assertEqual(([], 2), (self.other_changes, new_gen))
-
-    def test_sync_exchange_detect_incomplete_exchange(self):
-        def before_get_docs_explode(state):
-            if state != 'before get_docs':
-                return
-            raise errors.U1DBError("fail")
-        self.set_trace_hook(before_get_docs_explode)
-        # suppress traceback printing in the wsgiref server
-        self.patch(simple_server.ServerHandler,
-                   'log_exception', lambda h, exc_info: None)
-        doc = self.db.create_doc_from_json(simple_doc)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        self.assertRaises(
-            (errors.U1DBError, errors.BrokenSyncStream),
-            self.st.sync_exchange, [], 'other-replica',
-            last_known_generation=0, last_known_trans_id=None,
-            return_doc_cb=self.receive_doc)
-
-    def test_sync_exchange_doc_ids(self):
-        sync_exchange_doc_ids = getattr(self.st, 'sync_exchange_doc_ids', None)
-        if sync_exchange_doc_ids is None:
-            self.skipTest("sync_exchange_doc_ids not implemented")
-        db2 = self.create_database('test2')
-        doc = db2.create_doc_from_json(simple_doc)
-        new_gen, trans_id = sync_exchange_doc_ids(
-            db2, [(doc.doc_id, 10, 'T-sid')], 0, None,
-            return_doc_cb=self.receive_doc)
-        self.assertGetDoc(self.db, doc.doc_id, doc.rev, simple_doc, False)
-        self.assertTransactionLog([doc.doc_id], self.db)
-        last_trans_id = self.getLastTransId(self.db)
-        self.assertEqual(([], 1, last_trans_id),
-                         (self.other_changes, new_gen, trans_id))
-        self.assertEqual(10, self.st.get_sync_info(db2._replica_uid)[3])
-
-    def test__set_trace_hook(self):
-        called = []
-
-        def cb(state):
-            called.append(state)
-
-        self.set_trace_hook(cb)
-        self.st.sync_exchange([], 'replica', 0, None, self.receive_doc)
-        self.st.record_sync_info('replica', 0, 'T-sid')
-        self.assertEqual(['before whats_changed',
-                          'after whats_changed',
-                          'before get_docs',
-                          'record_sync_info',
-                          ],
-                         called)
-
-    def test__set_trace_hook_shallow(self):
-        if (self.st._set_trace_hook_shallow == self.st._set_trace_hook or
-            self.st._set_trace_hook_shallow.im_func ==
-                SyncTarget._set_trace_hook_shallow.im_func):
-            # shallow same as full
-            expected = ['before whats_changed',
-                        'after whats_changed',
-                        'before get_docs',
-                        'record_sync_info',
-                        ]
-        else:
-            expected = ['sync_exchange', 'record_sync_info']
-
-        called = []
-
-        def cb(state):
-            called.append(state)
-
-        self.set_trace_hook(cb, shallow=True)
-        self.st.sync_exchange([], 'replica', 0, None, self.receive_doc)
-        self.st.record_sync_info('replica', 0, 'T-sid')
-        self.assertEqual(expected, called)
-
-
-def sync_via_synchronizer(test, db_source, db_target, trace_hook=None,
-                          trace_hook_shallow=None):
-    target = db_target.get_sync_target()
-    trace_hook = trace_hook or trace_hook_shallow
-    if trace_hook:
-        target._set_trace_hook(trace_hook)
-    return sync.Synchronizer(db_source, target).sync()
-
-
-sync_scenarios = []
-for name, scenario in tests.LOCAL_DATABASES_SCENARIOS:
-    scenario = dict(scenario)
-    scenario['do_sync'] = sync_via_synchronizer
-    sync_scenarios.append((name, scenario))
-    scenario = dict(scenario)
-
-
-def make_database_for_http_test(test, replica_uid):
-    if test.server is None:
-        test.startServer()
-    db = test.request_state._create_database(replica_uid)
-    try:
-        http_at = test._http_at
-    except AttributeError:
-        http_at = test._http_at = {}
-    http_at[db] = replica_uid
-    return db
-
-
-def copy_database_for_http_test(test, db):
-    # DO NOT COPY OR REUSE THIS CODE OUTSIDE TESTS: COPYING U1DB DATABASES IS
-    # THE WRONG THING TO DO, THE ONLY REASON WE DO SO HERE IS TO TEST THAT WE
-    # CORRECTLY DETECT IT HAPPENING SO THAT WE CAN RAISE ERRORS RATHER THAN
-    # CORRUPT USER DATA. USE SYNC INSTEAD, OR WE WILL SEND NINJA TO YOUR HOUSE.
-    if test.server is None:
-        test.startServer()
-    new_db = test.request_state._copy_database(db)
-    try:
-        http_at = test._http_at
-    except AttributeError:
-        http_at = test._http_at = {}
-    path = db._replica_uid
-    while path in http_at.values():
-        path += 'copy'
-    http_at[new_db] = path
-    return new_db
-
-
-def sync_via_synchronizer_and_http(test, db_source, db_target,
-                                   trace_hook=None, trace_hook_shallow=None):
-    if trace_hook:
-        test.skipTest("full trace hook unsupported over http")
-    path = test._http_at[db_target]
-    target = http_target.HTTPSyncTarget.connect(test.getURL(path))
-    if trace_hook_shallow:
-        target._set_trace_hook_shallow(trace_hook_shallow)
-    return sync.Synchronizer(db_source, target).sync()
-
-
-sync_scenarios.append(('pyhttp', {
-    'make_database_for_test': make_database_for_http_test,
-    'copy_database_for_test': copy_database_for_http_test,
-    'make_document_for_test': tests.make_document_for_test,
-    'make_app_with_state': make_http_app,
-    'do_sync': sync_via_synchronizer_and_http
-}))
-
-
-@skip("Skiping tests imported from U1DB.")
-class DatabaseSyncTests(tests.DatabaseBaseTests,
-                        tests.TestCaseWithServer):
-
-    scenarios = sync_scenarios
-    do_sync = None                 # set by scenarios
-
-    def create_database(self, replica_uid, sync_role=None):
-        if replica_uid == 'test' and sync_role is None:
-            # created up the chain by base class but unused
-            return None
-        db = self.create_database_for_role(replica_uid, sync_role)
-        if sync_role:
-            self._use_tracking[db] = (replica_uid, sync_role)
-        return db
-
-    def create_database_for_role(self, replica_uid, sync_role):
-        # hook point for reuse
-        return super(DatabaseSyncTests, self).create_database(replica_uid)
-
-    def copy_database(self, db, sync_role=None):
-        # DO NOT COPY OR REUSE THIS CODE OUTSIDE TESTS: COPYING U1DB DATABASES
-        # IS THE WRONG THING TO DO, THE ONLY REASON WE DO SO HERE IS TO TEST
-        # THAT WE CORRECTLY DETECT IT HAPPENING SO THAT WE CAN RAISE ERRORS
-        # RATHER THAN CORRUPT USER DATA. USE SYNC INSTEAD, OR WE WILL SEND
-        # NINJA TO YOUR HOUSE.
-        db_copy = super(DatabaseSyncTests, self).copy_database(db)
-        name, orig_sync_role = self._use_tracking[db]
-        self._use_tracking[db_copy] = (name + '(copy)', sync_role or
-                                       orig_sync_role)
-        return db_copy
-
-    def sync(self, db_from, db_to, trace_hook=None,
-             trace_hook_shallow=None):
-        from_name, from_sync_role = self._use_tracking[db_from]
-        to_name, to_sync_role = self._use_tracking[db_to]
-        if from_sync_role not in ('source', 'both'):
-            raise Exception("%s marked for %s use but used as source" %
-                            (from_name, from_sync_role))
-        if to_sync_role not in ('target', 'both'):
-            raise Exception("%s marked for %s use but used as target" %
-                            (to_name, to_sync_role))
-        return self.do_sync(self, db_from, db_to, trace_hook,
-                            trace_hook_shallow)
-
-    def setUp(self):
-        self._use_tracking = {}
-        super(DatabaseSyncTests, self).setUp()
-
-    def assertLastExchangeLog(self, db, expected):
-        log = getattr(db, '_last_exchange_log', None)
-        if log is None:
-            return
-        self.assertEqual(expected, log)
-
-    def test_sync_tracks_db_generation_of_other(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.assertEqual(0, self.sync(self.db1, self.db2))
-        self.assertEqual(
-            (0, ''), self.db1._get_replica_gen_and_trans_id('test2'))
-        self.assertEqual(
-            (0, ''), self.db2._get_replica_gen_and_trans_id('test1'))
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [], 'last_known_gen': 0},
-                                    'return':
-                                       {'docs': [], 'last_gen': 0}})
-
-    def test_sync_autoresolves(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc1 = self.db1.create_doc_from_json(simple_doc, doc_id='doc')
-        rev1 = doc1.rev
-        doc2 = self.db2.create_doc_from_json(simple_doc, doc_id='doc')
-        rev2 = doc2.rev
-        self.sync(self.db1, self.db2)
-        doc = self.db1.get_doc('doc')
-        self.assertFalse(doc.has_conflicts)
-        self.assertEqual(doc.rev, self.db2.get_doc('doc').rev)
-        v = vectorclock.VectorClockRev(doc.rev)
-        self.assertTrue(v.is_newer(vectorclock.VectorClockRev(rev1)))
-        self.assertTrue(v.is_newer(vectorclock.VectorClockRev(rev2)))
-
-    def test_sync_autoresolves_moar(self):
-        # here we test that when a database that has a conflicted document is
-        # the source of a sync, and the target database has a revision of the
-        # conflicted document that is newer than the source database's, and
-        # that target's database's document's content is the same as the
-        # source's document's conflict's, the source's document's conflict gets
-        # autoresolved, and the source's document's revision bumped.
-        #
-        # idea is as follows:
-        # A          B
-        # a1         -
-        #   `------->
-        # a1         a1
-        # v          v
-        # a2         a1b1
-        #   `------->
-        # a1b1+a2    a1b1
-        #            v
-        # a1b1+a2    a1b2 (a1b2 has same content as a2)
-        #   `------->
-        # a3b2       a1b2 (autoresolved)
-        #   `------->
-        # a3b2       a3b2
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(simple_doc, doc_id='doc')
-        self.sync(self.db1, self.db2)
-        for db, content in [(self.db1, '{}'), (self.db2, '{"hi": 42}')]:
-            doc = db.get_doc('doc')
-            doc.set_json(content)
-            db.put_doc(doc)
-        self.sync(self.db1, self.db2)
-        # db1 and db2 now both have a doc of {hi:42}, but db1 has a conflict
-        doc = self.db1.get_doc('doc')
-        rev1 = doc.rev
-        self.assertTrue(doc.has_conflicts)
-        # set db2 to have a doc of {} (same as db1 before the conflict)
-        doc = self.db2.get_doc('doc')
-        doc.set_json('{}')
-        self.db2.put_doc(doc)
-        rev2 = doc.rev
-        # sync it across
-        self.sync(self.db1, self.db2)
-        # tadaa!
-        doc = self.db1.get_doc('doc')
-        self.assertFalse(doc.has_conflicts)
-        vec1 = vectorclock.VectorClockRev(rev1)
-        vec2 = vectorclock.VectorClockRev(rev2)
-        vec3 = vectorclock.VectorClockRev(doc.rev)
-        self.assertTrue(vec3.is_newer(vec1))
-        self.assertTrue(vec3.is_newer(vec2))
-        # because the conflict is on the source, sync it another time
-        self.sync(self.db1, self.db2)
-        # make sure db2 now has the exact same thing
-        self.assertEqual(self.db1.get_doc('doc'), self.db2.get_doc('doc'))
-
-    def test_sync_autoresolves_moar_backwards(self):
-        # here we test that when a database that has a conflicted document is
-        # the target of a sync, and the source database has a revision of the
-        # conflicted document that is newer than the target database's, and
-        # that source's database's document's content is the same as the
-        # target's document's conflict's, the target's document's conflict gets
-        # autoresolved, and the document's revision bumped.
-        #
-        # idea is as follows:
-        # A          B
-        # a1         -
-        #   `------->
-        # a1         a1
-        # v          v
-        # a2         a1b1
-        #   `------->
-        # a1b1+a2    a1b1
-        #            v
-        # a1b1+a2    a1b2 (a1b2 has same content as a2)
-        #   <-------'
-        # a3b2       a3b2 (autoresolved and propagated)
-        self.db1 = self.create_database('test1', 'both')
-        self.db2 = self.create_database('test2', 'both')
-        self.db1.create_doc_from_json(simple_doc, doc_id='doc')
-        self.sync(self.db1, self.db2)
-        for db, content in [(self.db1, '{}'), (self.db2, '{"hi": 42}')]:
-            doc = db.get_doc('doc')
-            doc.set_json(content)
-            db.put_doc(doc)
-        self.sync(self.db1, self.db2)
-        # db1 and db2 now both have a doc of {hi:42}, but db1 has a conflict
-        doc = self.db1.get_doc('doc')
-        rev1 = doc.rev
-        self.assertTrue(doc.has_conflicts)
-        revc = self.db1.get_doc_conflicts('doc')[-1].rev
-        # set db2 to have a doc of {} (same as db1 before the conflict)
-        doc = self.db2.get_doc('doc')
-        doc.set_json('{}')
-        self.db2.put_doc(doc)
-        rev2 = doc.rev
-        # sync it across
-        self.sync(self.db2, self.db1)
-        # tadaa!
-        doc = self.db1.get_doc('doc')
-        self.assertFalse(doc.has_conflicts)
-        vec1 = vectorclock.VectorClockRev(rev1)
-        vec2 = vectorclock.VectorClockRev(rev2)
-        vec3 = vectorclock.VectorClockRev(doc.rev)
-        vecc = vectorclock.VectorClockRev(revc)
-        self.assertTrue(vec3.is_newer(vec1))
-        self.assertTrue(vec3.is_newer(vec2))
-        self.assertTrue(vec3.is_newer(vecc))
-        # make sure db2 now has the exact same thing
-        self.assertEqual(self.db1.get_doc('doc'), self.db2.get_doc('doc'))
-
-    def test_sync_autoresolves_moar_backwards_three(self):
-        # same as autoresolves_moar_backwards, but with three databases (note
-        # all the syncs go in the same direction -- this is a more natural
-        # scenario):
-        #
-        # A          B          C
-        # a1         -          -
-        #   `------->
-        # a1         a1         -
-        #              `------->
-        # a1         a1         a1
-        # v          v
-        # a2         a1b1       a1
-        #  `------------------->
-        # a2         a1b1       a2
-        #              `------->
-        #            a2+a1b1    a2
-        #                       v
-        # a2         a2+a1b1    a2c1 (same as a1b1)
-        #  `------------------->
-        # a2c1       a2+a1b1    a2c1
-        #   `------->
-        # a2b2c1     a2b2c1     a2c1
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'both')
-        self.db3 = self.create_database('test3', 'target')
-        self.db1.create_doc_from_json(simple_doc, doc_id='doc')
-        self.sync(self.db1, self.db2)
-        self.sync(self.db2, self.db3)
-        for db, content in [(self.db2, '{"hi": 42}'),
-                            (self.db1, '{}'),
-                            ]:
-            doc = db.get_doc('doc')
-            doc.set_json(content)
-            db.put_doc(doc)
-        self.sync(self.db1, self.db3)
-        self.sync(self.db2, self.db3)
-        # db2 and db3 now both have a doc of {}, but db2 has a
-        # conflict
-        doc = self.db2.get_doc('doc')
-        self.assertTrue(doc.has_conflicts)
-        revc = self.db2.get_doc_conflicts('doc')[-1].rev
-        self.assertEqual('{}', doc.get_json())
-        self.assertEqual(self.db3.get_doc('doc').get_json(), doc.get_json())
-        self.assertEqual(self.db3.get_doc('doc').rev, doc.rev)
-        # set db3 to have a doc of {hi:42} (same as db2 before the conflict)
-        doc = self.db3.get_doc('doc')
-        doc.set_json('{"hi": 42}')
-        self.db3.put_doc(doc)
-        rev3 = doc.rev
-        # sync it across to db1
-        self.sync(self.db1, self.db3)
-        # db1 now has hi:42, with a rev that is newer than db2's doc
-        doc = self.db1.get_doc('doc')
-        rev1 = doc.rev
-        self.assertFalse(doc.has_conflicts)
-        self.assertEqual('{"hi": 42}', doc.get_json())
-        VCR = vectorclock.VectorClockRev
-        self.assertTrue(VCR(rev1).is_newer(VCR(self.db2.get_doc('doc').rev)))
-        # so sync it to db2
-        self.sync(self.db1, self.db2)
-        # tadaa!
-        doc = self.db2.get_doc('doc')
-        self.assertFalse(doc.has_conflicts)
-        # db2's revision of the document is strictly newer than db1's before
-        # the sync, and db3's before that sync way back when
-        self.assertTrue(VCR(doc.rev).is_newer(VCR(rev1)))
-        self.assertTrue(VCR(doc.rev).is_newer(VCR(rev3)))
-        self.assertTrue(VCR(doc.rev).is_newer(VCR(revc)))
-        # make sure both dbs now have the exact same thing
-        self.assertEqual(self.db1.get_doc('doc'), self.db2.get_doc('doc'))
-
-    def test_sync_puts_changes(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc = self.db1.create_doc_from_json(simple_doc)
-        self.assertEqual(1, self.sync(self.db1, self.db2))
-        self.assertGetDoc(self.db2, doc.doc_id, doc.rev, simple_doc, False)
-        self.assertEqual(1, self.db1._get_replica_gen_and_trans_id('test2')[0])
-        self.assertEqual(1, self.db2._get_replica_gen_and_trans_id('test1')[0])
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [(doc.doc_id, doc.rev)],
-                                        'source_uid': 'test1',
-                                        'source_gen': 1,
-                                        'last_known_gen': 0},
-                                    'return': {'docs': [], 'last_gen': 1}})
-
-    def test_sync_pulls_changes(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc = self.db2.create_doc_from_json(simple_doc)
-        self.db1.create_index('test-idx', 'key')
-        self.assertEqual(0, self.sync(self.db1, self.db2))
-        self.assertGetDoc(self.db1, doc.doc_id, doc.rev, simple_doc, False)
-        self.assertEqual(1, self.db1._get_replica_gen_and_trans_id('test2')[0])
-        self.assertEqual(1, self.db2._get_replica_gen_and_trans_id('test1')[0])
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [], 'last_known_gen': 0},
-                                    'return':
-                                       {'docs': [(doc.doc_id, doc.rev)],
-                                        'last_gen': 1}})
-        self.assertEqual([doc], self.db1.get_from_index('test-idx', 'value'))
-
-    def test_sync_pulling_doesnt_update_other_if_changed(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc = self.db2.create_doc_from_json(simple_doc)
-        # After the local side has sent its list of docs, before we start
-        # receiving the "targets" response, we update the local database with a
-        # new record.
-        # When we finish synchronizing, we can notice that something locally
-        # was updated, and we cannot tell c2 our new updated generation
-
-        def before_get_docs(state):
-            if state != 'before get_docs':
-                return
-            self.db1.create_doc_from_json(simple_doc)
-
-        self.assertEqual(0, self.sync(self.db1, self.db2,
-                                      trace_hook=before_get_docs))
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [], 'last_known_gen': 0},
-                                    'return':
-                                       {'docs': [(doc.doc_id, doc.rev)],
-                                        'last_gen': 1}})
-        self.assertEqual(1, self.db1._get_replica_gen_and_trans_id('test2')[0])
-        # c2 should not have gotten a '_record_sync_info' call, because the
-        # local database had been updated more than just by the messages
-        # returned from c2.
-        self.assertEqual(
-            (0, ''), self.db2._get_replica_gen_and_trans_id('test1'))
-
-    def test_sync_doesnt_update_other_if_nothing_pulled(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(simple_doc)
-
-        def no_record_sync_info(state):
-            if state != 'record_sync_info':
-                return
-            self.fail('SyncTarget.record_sync_info was called')
-        self.assertEqual(1, self.sync(self.db1, self.db2,
-                                      trace_hook_shallow=no_record_sync_info))
-        self.assertEqual(
-            1,
-            self.db2._get_replica_gen_and_trans_id(self.db1._replica_uid)[0])
-
-    def test_sync_ignores_convergence(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'both')
-        doc = self.db1.create_doc_from_json(simple_doc)
-        self.db3 = self.create_database('test3', 'target')
-        self.assertEqual(1, self.sync(self.db1, self.db3))
-        self.assertEqual(0, self.sync(self.db2, self.db3))
-        self.assertEqual(1, self.sync(self.db1, self.db2))
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [(doc.doc_id, doc.rev)],
-                                        'source_uid': 'test1',
-                                        'source_gen': 1, 'last_known_gen': 0},
-                                    'return': {'docs': [], 'last_gen': 1}})
-
-    def test_sync_ignores_superseded(self):
-        self.db1 = self.create_database('test1', 'both')
-        self.db2 = self.create_database('test2', 'both')
-        doc = self.db1.create_doc_from_json(simple_doc)
-        doc_rev1 = doc.rev
-        self.db3 = self.create_database('test3', 'target')
-        self.sync(self.db1, self.db3)
-        self.sync(self.db2, self.db3)
-        new_content = '{"key": "altval"}'
-        doc.set_json(new_content)
-        self.db1.put_doc(doc)
-        doc_rev2 = doc.rev
-        self.sync(self.db2, self.db1)
-        self.assertLastExchangeLog(self.db1,
-                                   {'receive':
-                                       {'docs': [(doc.doc_id, doc_rev1)],
-                                        'source_uid': 'test2',
-                                        'source_gen': 1, 'last_known_gen': 0},
-                                    'return':
-                                       {'docs': [(doc.doc_id, doc_rev2)],
-                                        'last_gen': 2}})
-        self.assertGetDoc(self.db1, doc.doc_id, doc_rev2, new_content, False)
-
-    def test_sync_sees_remote_conflicted(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc1 = self.db1.create_doc_from_json(simple_doc)
-        doc_id = doc1.doc_id
-        doc1_rev = doc1.rev
-        self.db1.create_index('test-idx', 'key')
-        new_doc = '{"key": "altval"}'
-        doc2 = self.db2.create_doc_from_json(new_doc, doc_id=doc_id)
-        doc2_rev = doc2.rev
-        self.assertTransactionLog([doc1.doc_id], self.db1)
-        self.sync(self.db1, self.db2)
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [(doc_id, doc1_rev)],
-                                        'source_uid': 'test1',
-                                        'source_gen': 1, 'last_known_gen': 0},
-                                    'return':
-                                       {'docs': [(doc_id, doc2_rev)],
-                                        'last_gen': 1}})
-        self.assertTransactionLog([doc_id, doc_id], self.db1)
-        self.assertGetDoc(self.db1, doc_id, doc2_rev, new_doc, True)
-        self.assertGetDoc(self.db2, doc_id, doc2_rev, new_doc, False)
-        from_idx = self.db1.get_from_index('test-idx', 'altval')[0]
-        self.assertEqual(doc2.doc_id, from_idx.doc_id)
-        self.assertEqual(doc2.rev, from_idx.rev)
-        self.assertTrue(from_idx.has_conflicts)
-        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
-
-    def test_sync_sees_remote_delete_conflicted(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc1 = self.db1.create_doc_from_json(simple_doc)
-        doc_id = doc1.doc_id
-        self.db1.create_index('test-idx', 'key')
-        self.sync(self.db1, self.db2)
-        doc2 = self.make_document(doc1.doc_id, doc1.rev, doc1.get_json())
-        new_doc = '{"key": "altval"}'
-        doc1.set_json(new_doc)
-        self.db1.put_doc(doc1)
-        self.db2.delete_doc(doc2)
-        self.assertTransactionLog([doc_id, doc_id], self.db1)
-        self.sync(self.db1, self.db2)
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [(doc_id, doc1.rev)],
-                                        'source_uid': 'test1',
-                                        'source_gen': 2, 'last_known_gen': 1},
-                                    'return': {'docs': [(doc_id, doc2.rev)],
-                                               'last_gen': 2}})
-        self.assertTransactionLog([doc_id, doc_id, doc_id], self.db1)
-        self.assertGetDocIncludeDeleted(self.db1, doc_id, doc2.rev, None, True)
-        self.assertGetDocIncludeDeleted(
-            self.db2, doc_id, doc2.rev, None, False)
-        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
-
-    def test_sync_local_race_conflicted(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        doc = self.db1.create_doc_from_json(simple_doc)
-        doc_id = doc.doc_id
-        doc1_rev = doc.rev
-        self.db1.create_index('test-idx', 'key')
-        self.sync(self.db1, self.db2)
-        content1 = '{"key": "localval"}'
-        content2 = '{"key": "altval"}'
-        doc.set_json(content2)
-        self.db2.put_doc(doc)
-        doc2_rev2 = doc.rev
-        triggered = []
-
-        def after_whatschanged(state):
-            if state != 'after whats_changed':
-                return
-            triggered.append(True)
-            doc = self.make_document(doc_id, doc1_rev, content1)
-            self.db1.put_doc(doc)
-
-        self.sync(self.db1, self.db2, trace_hook=after_whatschanged)
-        self.assertEqual([True], triggered)
-        self.assertGetDoc(self.db1, doc_id, doc2_rev2, content2, True)
-        from_idx = self.db1.get_from_index('test-idx', 'altval')[0]
-        self.assertEqual(doc.doc_id, from_idx.doc_id)
-        self.assertEqual(doc.rev, from_idx.rev)
-        self.assertTrue(from_idx.has_conflicts)
-        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
-        self.assertEqual([], self.db1.get_from_index('test-idx', 'localval'))
-
-    def test_sync_propagates_deletes(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'both')
-        doc1 = self.db1.create_doc_from_json(simple_doc)
-        doc_id = doc1.doc_id
-        self.db1.create_index('test-idx', 'key')
-        self.sync(self.db1, self.db2)
-        self.db2.create_index('test-idx', 'key')
-        self.db3 = self.create_database('test3', 'target')
-        self.sync(self.db1, self.db3)
-        self.db1.delete_doc(doc1)
-        deleted_rev = doc1.rev
-        self.sync(self.db1, self.db2)
-        self.assertLastExchangeLog(self.db2,
-                                   {'receive':
-                                       {'docs': [(doc_id, deleted_rev)],
-                                        'source_uid': 'test1',
-                                        'source_gen': 2, 'last_known_gen': 1},
-                                    'return': {'docs': [], 'last_gen': 2}})
-        self.assertGetDocIncludeDeleted(
-            self.db1, doc_id, deleted_rev, None, False)
-        self.assertGetDocIncludeDeleted(
-            self.db2, doc_id, deleted_rev, None, False)
-        self.assertEqual([], self.db1.get_from_index('test-idx', 'value'))
-        self.assertEqual([], self.db2.get_from_index('test-idx', 'value'))
-        self.sync(self.db2, self.db3)
-        self.assertLastExchangeLog(self.db3,
-                                   {'receive':
-                                       {'docs': [(doc_id, deleted_rev)],
-                                        'source_uid': 'test2',
-                                        'source_gen': 2,
-                                        'last_known_gen': 0},
-                                    'return':
-                                       {'docs': [], 'last_gen': 2}})
-        self.assertGetDocIncludeDeleted(
-            self.db3, doc_id, deleted_rev, None, False)
-
-    def test_sync_propagates_resolution(self):
-        self.db1 = self.create_database('test1', 'both')
-        self.db2 = self.create_database('test2', 'both')
-        doc1 = self.db1.create_doc_from_json('{"a": 1}', doc_id='the-doc')
-        db3 = self.create_database('test3', 'both')
-        self.sync(self.db2, self.db1)
-        self.assertEqual(
-            self.db1._get_generation_info(),
-            self.db2._get_replica_gen_and_trans_id(self.db1._replica_uid))
-        self.assertEqual(
-            self.db2._get_generation_info(),
-            self.db1._get_replica_gen_and_trans_id(self.db2._replica_uid))
-        self.sync(db3, self.db1)
-        # update on 2
-        doc2 = self.make_document('the-doc', doc1.rev, '{"a": 2}')
-        self.db2.put_doc(doc2)
-        self.sync(self.db2, db3)
-        self.assertEqual(db3.get_doc('the-doc').rev, doc2.rev)
-        # update on 1
-        doc1.set_json('{"a": 3}')
-        self.db1.put_doc(doc1)
-        # conflicts
-        self.sync(self.db2, self.db1)
-        self.sync(db3, self.db1)
-        self.assertTrue(self.db2.get_doc('the-doc').has_conflicts)
-        self.assertTrue(db3.get_doc('the-doc').has_conflicts)
-        # resolve
-        conflicts = self.db2.get_doc_conflicts('the-doc')
-        doc4 = self.make_document('the-doc', None, '{"a": 4}')
-        revs = [doc.rev for doc in conflicts]
-        self.db2.resolve_doc(doc4, revs)
-        doc2 = self.db2.get_doc('the-doc')
-        self.assertEqual(doc4.get_json(), doc2.get_json())
-        self.assertFalse(doc2.has_conflicts)
-        self.sync(self.db2, db3)
-        doc3 = db3.get_doc('the-doc')
-        self.assertEqual(doc4.get_json(), doc3.get_json())
-        self.assertFalse(doc3.has_conflicts)
-
-    def test_sync_supersedes_conflicts(self):
-        self.db1 = self.create_database('test1', 'both')
-        self.db2 = self.create_database('test2', 'target')
-        self.db3 = self.create_database('test3', 'both')
-        doc1 = self.db1.create_doc_from_json('{"a": 1}', doc_id='the-doc')
-        self.db2.create_doc_from_json('{"b": 1}', doc_id='the-doc')
-        self.db3.create_doc_from_json('{"c": 1}', doc_id='the-doc')
-        self.sync(self.db3, self.db1)
-        self.assertEqual(
-            self.db1._get_generation_info(),
-            self.db3._get_replica_gen_and_trans_id(self.db1._replica_uid))
-        self.assertEqual(
-            self.db3._get_generation_info(),
-            self.db1._get_replica_gen_and_trans_id(self.db3._replica_uid))
-        self.sync(self.db3, self.db2)
-        self.assertEqual(
-            self.db2._get_generation_info(),
-            self.db3._get_replica_gen_and_trans_id(self.db2._replica_uid))
-        self.assertEqual(
-            self.db3._get_generation_info(),
-            self.db2._get_replica_gen_and_trans_id(self.db3._replica_uid))
-        self.assertEqual(3, len(self.db3.get_doc_conflicts('the-doc')))
-        doc1.set_json('{"a": 2}')
-        self.db1.put_doc(doc1)
-        self.sync(self.db3, self.db1)
-        # original doc1 should have been removed from conflicts
-        self.assertEqual(3, len(self.db3.get_doc_conflicts('the-doc')))
-
-    def test_sync_stops_after_get_sync_info(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(tests.simple_doc)
-        self.sync(self.db1, self.db2)
-
-        def put_hook(state):
-            self.fail("Tracehook triggered for %s" % (state,))
-
-        self.sync(self.db1, self.db2, trace_hook_shallow=put_hook)
-
-    def test_sync_detects_rollback_in_source(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc1')
-        self.sync(self.db1, self.db2)
-        self.db1_copy = self.copy_database(self.db1)
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc2')
-        self.sync(self.db1, self.db2)
-        self.assertRaises(
-            errors.InvalidGeneration, self.sync, self.db1_copy, self.db2)
-
-    def test_sync_detects_rollback_in_target(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
-        self.sync(self.db1, self.db2)
-        self.db2_copy = self.copy_database(self.db2)
-        self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc2')
-        self.sync(self.db1, self.db2)
-        self.assertRaises(
-            errors.InvalidGeneration, self.sync, self.db1, self.db2_copy)
-
-    def test_sync_detects_diverged_source(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db3 = self.copy_database(self.db1)
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
-        self.db3.create_doc_from_json(tests.simple_doc, doc_id="divergent")
-        self.sync(self.db1, self.db2)
-        self.assertRaises(
-            errors.InvalidTransactionId, self.sync, self.db3, self.db2)
-
-    def test_sync_detects_diverged_target(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db3 = self.copy_database(self.db2)
-        self.db3.create_doc_from_json(tests.nested_doc, doc_id="divergent")
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
-        self.sync(self.db1, self.db2)
-        self.assertRaises(
-            errors.InvalidTransactionId, self.sync, self.db1, self.db3)
-
-    def test_sync_detects_rollback_and_divergence_in_source(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc1')
-        self.sync(self.db1, self.db2)
-        self.db1_copy = self.copy_database(self.db1)
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc2')
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id='doc3')
-        self.sync(self.db1, self.db2)
-        self.db1_copy.create_doc_from_json(tests.simple_doc, doc_id='doc2')
-        self.db1_copy.create_doc_from_json(tests.simple_doc, doc_id='doc3')
-        self.assertRaises(
-            errors.InvalidTransactionId, self.sync, self.db1_copy, self.db2)
-
-    def test_sync_detects_rollback_and_divergence_in_target(self):
-        self.db1 = self.create_database('test1', 'source')
-        self.db2 = self.create_database('test2', 'target')
-        self.db1.create_doc_from_json(tests.simple_doc, doc_id="divergent")
-        self.sync(self.db1, self.db2)
-        self.db2_copy = self.copy_database(self.db2)
-        self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc2')
-        self.db2.create_doc_from_json(tests.simple_doc, doc_id='doc3')
-        self.sync(self.db1, self.db2)
-        self.db2_copy.create_doc_from_json(tests.simple_doc, doc_id='doc2')
-        self.db2_copy.create_doc_from_json(tests.simple_doc, doc_id='doc3')
-        self.assertRaises(
-            errors.InvalidTransactionId, self.sync, self.db1, self.db2_copy)
-
-
-@skip("Skiping tests imported from U1DB.")
-class TestDbSync(tests.TestCaseWithServer):
-
-    """Test db.sync remote sync shortcut"""
-
-    scenarios = [
-        ('py-http', {
-            'make_app_with_state': make_http_app,
-            'make_database_for_test': tests.make_memory_database_for_test,
-        }),
-        ('py-oauth-http', {
-            'make_app_with_state': make_oauth_http_app,
-            'make_database_for_test': tests.make_memory_database_for_test,
-            'oauth': True
-        }),
-    ]
-
-    oauth = False
-
-    def do_sync(self, target_name):
-        if self.oauth:
-            path = '~/' + target_name
-            extra = dict(creds={'oauth': {
-                'consumer_key': tests.consumer1.key,
-                'consumer_secret': tests.consumer1.secret,
-                'token_key': tests.token1.key,
-                'token_secret': tests.token1.secret,
-            }})
-        else:
-            path = target_name
-            extra = {}
-        target_url = self.getURL(path)
-        return self.db.sync(target_url, **extra)
-
-    def sync(self, callback=None, autocreate=False, defer_decryption=False):
-        return super(TestDbSync, self).sync(callback, autocreate)
-
-    def setUp(self):
-        super(TestDbSync, self).setUp()
-        self.startServer()
-        self.db = self.make_database_for_test(self, 'test1')
-        self.db2 = self.request_state._create_database('test2')
-
-    def test_db_sync(self):
-        doc1 = self.db.create_doc_from_json(tests.simple_doc)
-        doc2 = self.db2.create_doc_from_json(tests.nested_doc)
-        local_gen_before_sync = self.do_sync('test2')
-        gen, _, changes = self.db.whats_changed(local_gen_before_sync)
-        self.assertEqual(1, len(changes))
-        self.assertEqual(doc2.doc_id, changes[0][0])
-        self.assertEqual(1, gen - local_gen_before_sync)
-        self.assertGetDoc(self.db2, doc1.doc_id, doc1.rev, tests.simple_doc,
-                          False)
-        self.assertGetDoc(self.db, doc2.doc_id, doc2.rev, tests.nested_doc,
-                          False)
-
-    def test_db_sync_autocreate(self):
-        doc1 = self.db.create_doc_from_json(tests.simple_doc)
-        local_gen_before_sync = self.do_sync('test3.db')
-        gen, _, changes = self.db.whats_changed(local_gen_before_sync)
-        self.assertEqual(0, gen - local_gen_before_sync)
-        db3 = self.request_state.open_database('test3.db')
-        gen, _, changes = db3.whats_changed()
-        self.assertEqual(1, len(changes))
-        self.assertEqual(doc1.doc_id, changes[0][0])
-        self.assertGetDoc(db3, doc1.doc_id, doc1.rev, tests.simple_doc,
-                          False)
-        t_gen, _ = self.db._get_replica_gen_and_trans_id('test3.db')
-        s_gen, _ = db3._get_replica_gen_and_trans_id('test1')
-        self.assertEqual(1, t_gen)
-        self.assertEqual(1, s_gen)
-
-
-@skip("Skiping tests imported from U1DB.")
-class TestRemoteSyncIntegration(tests.TestCaseWithServer):
-
-    """Integration tests for the most common sync scenario local -> remote"""
-
-    make_app_with_state = staticmethod(make_http_app)
-
-    def setUp(self):
-        super(TestRemoteSyncIntegration, self).setUp()
-        self.startServer()
-        self.db1 = inmemory.InMemoryDatabase('test1')
-        self.db2 = self.request_state._create_database('test2')
-
-    def test_sync_tracks_generations_incrementally(self):
-        doc11 = self.db1.create_doc_from_json('{"a": 1}')
-        doc12 = self.db1.create_doc_from_json('{"a": 2}')
-        doc21 = self.db2.create_doc_from_json('{"b": 1}')
-        doc22 = self.db2.create_doc_from_json('{"b": 2}')
-        # sanity
-        self.assertEqual(2, len(self.db1._get_transaction_log()))
-        self.assertEqual(2, len(self.db2._get_transaction_log()))
-        progress1 = []
-        progress2 = []
-        _do_set_replica_gen_and_trans_id = \
-            self.db1._do_set_replica_gen_and_trans_id
-
-        def set_sync_generation_witness1(other_uid, other_gen, trans_id):
-            progress1.append((other_uid, other_gen,
-                              [d for d, t in
-                                  self.db1._get_transaction_log()[2:]]))
-            _do_set_replica_gen_and_trans_id(other_uid, other_gen, trans_id)
-        self.patch(self.db1, '_do_set_replica_gen_and_trans_id',
-                   set_sync_generation_witness1)
-        _do_set_replica_gen_and_trans_id2 = \
-            self.db2._do_set_replica_gen_and_trans_id
-
-        def set_sync_generation_witness2(other_uid, other_gen, trans_id):
-            progress2.append((other_uid, other_gen,
-                              [d for d, t in
-                                  self.db2._get_transaction_log()[2:]]))
-            _do_set_replica_gen_and_trans_id2(other_uid, other_gen, trans_id)
-        self.patch(self.db2, '_do_set_replica_gen_and_trans_id',
-                   set_sync_generation_witness2)
-
-        db2_url = self.getURL('test2')
-        self.db1.sync(db2_url)
-
-        self.assertEqual([('test2', 1, [doc21.doc_id]),
-                          ('test2', 2, [doc21.doc_id, doc22.doc_id]),
-                          ('test2', 4, [doc21.doc_id, doc22.doc_id])],
-                         progress1)
-        self.assertEqual([('test1', 1, [doc11.doc_id]),
-                          ('test1', 2, [doc11.doc_id, doc12.doc_id]),
-                          ('test1', 4, [doc11.doc_id, doc12.doc_id])],
-                         progress2)
-
-
-load_tests = tests.load_with_scenarios