Fix state tests

1 files changed, 176 insertions, 517 deletions

diff --git a/tests/test_state.py b/tests/test_state.py
index 4b1feaf410..3cc358be32 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -15,599 +15,258 @@
 
 from tests import unittest
 from twisted.internet import defer
-from twisted.python.log import PythonLoggingObserver
 
 from synapse.state import StateHandler
-from synapse.storage.pdu import PduEntry
-from synapse.federation.pdu_codec import encode_event_id
-from synapse.federation.units import Pdu
-
-from collections import namedtuple
 
 from mock import Mock
 
-import mock
-
-
-ReturnType = namedtuple(
-    "StateReturnType", ["new_branch", "current_branch"]
-)
-
-
-def _gen_get_power_level(power_level_list):
-    def get_power_level(room_id, user_id):
-        return defer.succeed(power_level_list.get(user_id, None))
-    return get_power_level
 
 class StateTestCase(unittest.TestCase):
     def setUp(self):
-        self.persistence = Mock(spec=[
-            "get_unresolved_state_tree",
-            "update_current_state",
-            "get_latest_pdus_in_context",
-            "get_current_state_pdu",
-            "get_pdu",
-            "get_power_level",
-        ])
-        self.replication = Mock(spec=["get_pdu"])
-
-        hs = Mock(spec=["get_datastore", "get_replication_layer"])
-        hs.get_datastore.return_value = self.persistence
-        hs.get_replication_layer.return_value = self.replication
-        hs.hostname = "bob.com"
-
-        self.state = StateHandler(hs)
-
-    @defer.inlineCallbacks
-    def test_new_state_key(self):
-        # We've never seen anything for this state before
-        new_pdu = new_fake_pdu("A", "test", "mem", "x", None, "u")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({})
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu], []), None)
-        )
-
-        is_new = yield self.state.handle_new_state(new_pdu)
-
-        self.assertTrue(is_new)
-
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
-        )
-
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
-
-        self.assertFalse(self.replication.get_pdu.called)
-
-    @defer.inlineCallbacks
-    def test_direct_overwrite(self):
-        # We do a direct overwriting of the old state, i.e., the new state
-        # points to the old state.
-
-        old_pdu = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        new_pdu = new_fake_pdu("B", "test", "mem", "x", "A", "u2")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 5,
-        })
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu, old_pdu], [old_pdu]), None)
-        )
-
-        is_new = yield self.state.handle_new_state(new_pdu)
-
-        self.assertTrue(is_new)
-
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
+        self.store = Mock(
+            spec_set=[
+                "get_state_groups",
+            ]
         )
+        hs = Mock(spec=["get_datastore"])
+        hs.get_datastore.return_value = self.store
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
-
-        self.assertFalse(self.replication.get_pdu.called)
+        self.state = StateHandler(hs)
+        self.event_id = 0
 
     @defer.inlineCallbacks
-    def test_overwrite(self):
-        old_pdu_1 = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        old_pdu_2 = new_fake_pdu("B", "test", "mem", "x", "A", "u2")
-        new_pdu = new_fake_pdu("C", "test", "mem", "x", "B", "u3")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 5,
-            "u3": 0,
-        })
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu, old_pdu_2, old_pdu_1], [old_pdu_1]), None)
-        )
+    def test_annotate_with_old_message(self):
+        event = self.create_event(type="test_message", name="event")
 
-        is_new = yield self.state.handle_new_state(new_pdu)
+        old_state = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test1", state_key="2"),
+            self.create_event(type="test2", state_key=""),
+        ]
 
-        self.assertTrue(is_new)
+        yield self.state.annotate_state_groups(event, old_state=old_state)
 
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
-        )
+        for k, v in event.old_state_events.items():
+            type, state_key = k
+            self.assertEqual(type, v.type)
+            self.assertEqual(state_key, v.state_key)
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
+        self.assertEqual(set(old_state), set(event.old_state_events.values()))
+        self.assertDictEqual(event.old_state_events, event.state_events)
 
-        self.assertFalse(self.replication.get_pdu.called)
+        self.assertIsNone(event.state_group)
 
     @defer.inlineCallbacks
-    def test_power_level_fail(self):
-        # We try to update the state based on an outdated state, and have a
-        # too low power level.
-
-        old_pdu_1 = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        old_pdu_2 = new_fake_pdu("B", "test", "mem", "x", None, "u2")
-        new_pdu = new_fake_pdu("C", "test", "mem", "x", "A", "u3")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 5,
-        })
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu, old_pdu_1], [old_pdu_2, old_pdu_1]), None)
-        )
-
-        is_new = yield self.state.handle_new_state(new_pdu)
-
-        self.assertFalse(is_new)
-
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
-        )
-
-        self.assertEqual(0, self.persistence.update_current_state.call_count)
+    def test_annotate_with_old_state(self):
+        event = self.create_event(type="state", state_key="", name="event")
 
-        self.assertFalse(self.replication.get_pdu.called)
-
-    @defer.inlineCallbacks
-    def test_power_level_succeed(self):
-        # We try to update the state based on an outdated state, but have
-        # sufficient power level to force the update.
-
-        old_pdu_1 = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        old_pdu_2 = new_fake_pdu("B", "test", "mem", "x", None, "u2")
-        new_pdu = new_fake_pdu("C", "test", "mem", "x", "A", "u3")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 15,
-        })
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu, old_pdu_1], [old_pdu_2, old_pdu_1]), None)
-        )
+        old_state = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test1", state_key="2"),
+            self.create_event(type="test2", state_key=""),
+        ]
 
-        is_new = yield self.state.handle_new_state(new_pdu)
+        yield self.state.annotate_state_groups(event, old_state=old_state)
 
-        self.assertTrue(is_new)
+        for k, v in event.old_state_events.items():
+            type, state_key = k
+            self.assertEqual(type, v.type)
+            self.assertEqual(state_key, v.state_key)
 
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
+        self.assertEqual(
+            set(old_state + [event]),
+            set(event.old_state_events.values())
         )
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
+        self.assertDictEqual(event.old_state_events, event.state_events)
 
-        self.assertFalse(self.replication.get_pdu.called)
+        self.assertIsNone(event.state_group)
 
     @defer.inlineCallbacks
-    def test_power_level_equal_same_len(self):
-        # We try to update the state based on an outdated state, the power
-        # levels are the same and so are the branch lengths
-
-        old_pdu_1 = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        old_pdu_2 = new_fake_pdu("B", "test", "mem", "x", None, "u2")
-        new_pdu = new_fake_pdu("C", "test", "mem", "x", "A", "u3")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 10,
-        })
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu, old_pdu_1], [old_pdu_2, old_pdu_1]), None)
-        )
-
-        is_new = yield self.state.handle_new_state(new_pdu)
+    def test_trivial_annotate_message(self):
+        event = self.create_event(type="test_message", name="event")
+        event.prev_events = []
+
+        old_state = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test1", state_key="2"),
+            self.create_event(type="test2", state_key=""),
+        ]
 
-        self.assertTrue(is_new)
+        group_name = "group_name_1"
 
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
-        )
+        self.store.get_state_groups.return_value = {
+            group_name: old_state,
+        }
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
+        yield self.state.annotate_state_groups(event)
 
-        self.assertFalse(self.replication.get_pdu.called)
+        for k, v in event.old_state_events.items():
+            type, state_key = k
+            self.assertEqual(type, v.type)
+            self.assertEqual(state_key, v.state_key)
 
-    @defer.inlineCallbacks
-    def test_power_level_equal_diff_len(self):
-        # We try to update the state based on an outdated state, the power
-        # levels are the same but the branch length of the new one is longer.
-
-        old_pdu_1 = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        old_pdu_2 = new_fake_pdu("B", "test", "mem", "x", None, "u2")
-        old_pdu_3 = new_fake_pdu("C", "test", "mem", "x", "A", "u3")
-        new_pdu = new_fake_pdu("D", "test", "mem", "x", "C", "u4")
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 10,
-            "u4": 10,
-        })
-
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (
-                ReturnType(
-                    [new_pdu, old_pdu_3, old_pdu_1],
-                    [old_pdu_2, old_pdu_1]
-                ),
-                None
-            )
+        self.assertEqual(
+            set([e.event_id for e in old_state]),
+            set([e.event_id for e in event.old_state_events.values()])
         )
 
-        is_new = yield self.state.handle_new_state(new_pdu)
-
-        self.assertTrue(is_new)
-
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
+        self.assertDictEqual(
+            {
+                k: v.event_id
+                for k, v in event.old_state_events.items()
+            },
+            {
+                k: v.event_id
+                for k, v in event.state_events.items()
+            }
         )
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
-
-        self.assertFalse(self.replication.get_pdu.called)
+        self.assertEqual(group_name, event.state_group)
 
     @defer.inlineCallbacks
-    def test_missing_pdu(self):
-        # We try to update state against a PDU we haven't yet seen,
-        # triggering a get_pdu request
-
-        # The pdu we haven't seen
-        old_pdu_1 = new_fake_pdu(
-            "A", "test", "mem", "x", None, "u1", depth=0
-        )
-
-        old_pdu_2 = new_fake_pdu(
-            "B", "test", "mem", "x", "A", "u2", depth=1
-        )
-        new_pdu = new_fake_pdu(
-            "C", "test", "mem", "x", "A", "u3", depth=2
-        )
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 20,
-        })
-
-        # The return_value of `get_unresolved_state_tree`, which changes after
-        # the call to get_pdu
-        tree_to_return = [(ReturnType([new_pdu], [old_pdu_2]), 0)]
-
-        def return_tree(p):
-            return tree_to_return[0]
-
-        def set_return_tree(destination, pdu_origin, pdu_id, outlier=False):
-            tree_to_return[0] = (
-                ReturnType(
-                    [new_pdu, old_pdu_1], [old_pdu_2, old_pdu_1]
-                ),
-                None
-            )
-            return defer.succeed(None)
-
-        self.persistence.get_unresolved_state_tree.side_effect = return_tree
+    def test_trivial_annotate_state(self):
+        event = self.create_event(type="state", state_key="", name="event")
+        event.prev_events = []
+
+        old_state = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test1", state_key="2"),
+            self.create_event(type="test2", state_key=""),
+        ]
 
-        self.replication.get_pdu.side_effect = set_return_tree
+        group_name = "group_name_1"
 
-        self.persistence.get_pdu.return_value = None
+        self.store.get_state_groups.return_value = {
+            group_name: old_state,
+        }
 
-        is_new = yield self.state.handle_new_state(new_pdu)
+        yield self.state.annotate_state_groups(event)
 
-        self.assertTrue(is_new)
+        for k, v in event.old_state_events.items():
+            type, state_key = k
+            self.assertEqual(type, v.type)
+            self.assertEqual(state_key, v.state_key)
 
-        self.replication.get_pdu.assert_called_with(
-            destination=new_pdu.origin,
-            pdu_origin=old_pdu_1.origin,
-            pdu_id=old_pdu_1.pdu_id,
-            outlier=True
+        self.assertEqual(
+            set([e.event_id for e in old_state]),
+            set([e.event_id for e in event.old_state_events.values()])
         )
 
-        self.persistence.get_unresolved_state_tree.assert_called_with(
-            new_pdu
+        self.assertEqual(
+            set([e.event_id for e in old_state] + [event.event_id]),
+            set([e.event_id for e in event.state_events.values()])
         )
 
-        self.assertEquals(
-            2, self.persistence.get_unresolved_state_tree.call_count
+        new_state = {
+            k: v.event_id
+            for k, v in event.state_events.items()
+        }
+        old_state = {
+            k: v.event_id
+            for k, v in event.old_state_events.items()
+        }
+        old_state[(event.type, event.state_key)] = event.event_id
+        self.assertDictEqual(
+            old_state,
+            new_state
         )
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
+        self.assertIsNone(event.state_group)
 
     @defer.inlineCallbacks
-    def test_missing_pdu_depth_1(self):
-        # We try to update state against a PDU we haven't yet seen,
-        # triggering a get_pdu request
-
-        # The pdu we haven't seen
-        old_pdu_1 = new_fake_pdu(
-            "A", "test", "mem", "x", None, "u1", depth=0
-        )
-
-        old_pdu_2 = new_fake_pdu(
-            "B", "test", "mem", "x", "A", "u2", depth=2
-        )
-        old_pdu_3 = new_fake_pdu(
-            "C", "test", "mem", "x", "B", "u3", depth=3
-        )
-        new_pdu = new_fake_pdu(
-            "D", "test", "mem", "x", "A", "u4", depth=4
-        )
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 10,
-            "u4": 20,
-        })
-
-        # The return_value of `get_unresolved_state_tree`, which changes after
-        # the call to get_pdu
-        tree_to_return = [
-            (
-                ReturnType([new_pdu], [old_pdu_3]),
-                0
-            ),
-            (
-                ReturnType(
-                    [new_pdu, old_pdu_1], [old_pdu_3]
-                ),
-                1
-            ),
-            (
-                ReturnType(
-                    [new_pdu, old_pdu_1], [old_pdu_3, old_pdu_2, old_pdu_1]
-                ),
-                None
-            ),
+    def test_resolve_message_conflict(self):
+        event = self.create_event(type="test_message", name="event")
+        event.prev_events = []
+
+        old_state_1 = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test1", state_key="2"),
+            self.create_event(type="test2", state_key=""),
         ]
 
-        to_return = [0]
-
-        def return_tree(p):
-            return tree_to_return[to_return[0]]
-
-        def set_return_tree(destination, pdu_origin, pdu_id, outlier=False):
-            to_return[0] += 1
-            return defer.succeed(None)
-
-        self.persistence.get_unresolved_state_tree.side_effect = return_tree
-
-        self.replication.get_pdu.side_effect = set_return_tree
-
-        self.persistence.get_pdu.return_value = None
-
-        is_new = yield self.state.handle_new_state(new_pdu)
+        old_state_2 = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test3", state_key="2"),
+            self.create_event(type="test4", state_key=""),
+        ]
 
-        self.assertTrue(is_new)
+        group_name_1 = "group_name_1"
+        group_name_2 = "group_name_2"
 
-        self.assertEqual(2, self.replication.get_pdu.call_count)
+        self.store.get_state_groups.return_value = {
+            group_name_1: old_state_1,
+            group_name_2: old_state_2,
+        }
 
-        self.replication.get_pdu.assert_has_calls(
-            [
-                mock.call(
-                    destination=new_pdu.origin,
-                    pdu_origin=old_pdu_1.origin,
-                    pdu_id=old_pdu_1.pdu_id,
-                    outlier=True
-                ),
-                mock.call(
-                    destination=old_pdu_3.origin,
-                    pdu_origin=old_pdu_2.origin,
-                    pdu_id=old_pdu_2.pdu_id,
-                    outlier=True
-                ),
-            ]
-        )
+        yield self.state.annotate_state_groups(event)
 
-        self.persistence.get_unresolved_state_tree.assert_called_with(
-            new_pdu
-        )
+        self.assertEqual(len(event.old_state_events), 5)
 
-        self.assertEquals(
-            3, self.persistence.get_unresolved_state_tree.call_count
+        self.assertEqual(
+            set([e.event_id for e in event.state_events.values()]),
+            set([e.event_id for e in event.old_state_events.values()])
         )
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
+        self.assertIsNone(event.state_group)
 
     @defer.inlineCallbacks
-    def test_missing_pdu_depth_2(self):
-        # We try to update state against a PDU we haven't yet seen,
-        # triggering a get_pdu request
-
-        # The pdu we haven't seen
-        old_pdu_1 = new_fake_pdu(
-            "A", "test", "mem", "x", None, "u1", depth=0
-        )
-
-        old_pdu_2 = new_fake_pdu(
-            "B", "test", "mem", "x", "A", "u2", depth=2
-        )
-        old_pdu_3 = new_fake_pdu(
-            "C", "test", "mem", "x", "B", "u3", depth=3
-        )
-        new_pdu = new_fake_pdu(
-            "D", "test", "mem", "x", "A", "u4", depth=1
-        )
-
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 10,
-            "u2": 10,
-            "u3": 10,
-            "u4": 20,
-        })
-
-        # The return_value of `get_unresolved_state_tree`, which changes after
-        # the call to get_pdu
-        tree_to_return = [
-            (
-                ReturnType([new_pdu], [old_pdu_3]),
-                1,
-            ),
-            (
-                ReturnType(
-                    [new_pdu], [old_pdu_3, old_pdu_2]
-                ),
-                0,
-            ),
-            (
-                ReturnType(
-                    [new_pdu, old_pdu_1], [old_pdu_3, old_pdu_2, old_pdu_1]
-                ),
-                None
-            ),
+    def test_resolve_state_conflict(self):
+        event = self.create_event(type="test4", state_key="", name="event")
+        event.prev_events = []
+
+        old_state_1 = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test1", state_key="2"),
+            self.create_event(type="test2", state_key=""),
         ]
 
-        to_return = [0]
-
-        def return_tree(p):
-            return tree_to_return[to_return[0]]
-
-        def set_return_tree(destination, pdu_origin, pdu_id, outlier=False):
-            to_return[0] += 1
-            return defer.succeed(None)
-
-        self.persistence.get_unresolved_state_tree.side_effect = return_tree
-
-        self.replication.get_pdu.side_effect = set_return_tree
-
-        self.persistence.get_pdu.return_value = None
-
-        is_new = yield self.state.handle_new_state(new_pdu)
-
-        self.assertTrue(is_new)
-
-        self.assertEqual(2, self.replication.get_pdu.call_count)
-
-        self.replication.get_pdu.assert_has_calls(
-            [
-                mock.call(
-                    destination=old_pdu_3.origin,
-                    pdu_origin=old_pdu_2.origin,
-                    pdu_id=old_pdu_2.pdu_id,
-                    outlier=True
-                ),
-                mock.call(
-                    destination=new_pdu.origin,
-                    pdu_origin=old_pdu_1.origin,
-                    pdu_id=old_pdu_1.pdu_id,
-                    outlier=True
-                ),
-            ]
-        )
-
-        self.persistence.get_unresolved_state_tree.assert_called_with(
-            new_pdu
-        )
-
-        self.assertEquals(
-            3, self.persistence.get_unresolved_state_tree.call_count
-        )
-
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
-
-    @defer.inlineCallbacks
-    def test_no_common_ancestor(self):
-        # We do a direct overwriting of the old state, i.e., the new state
-        # points to the old state.
+        old_state_2 = [
+            self.create_event(type="test1", state_key="1"),
+            self.create_event(type="test3", state_key="2"),
+            self.create_event(type="test4", state_key=""),
+        ]
 
-        old_pdu = new_fake_pdu("A", "test", "mem", "x", None, "u1")
-        new_pdu = new_fake_pdu("B", "test", "mem", "x", None, "u2")
+        group_name_1 = "group_name_1"
+        group_name_2 = "group_name_2"
 
-        self.persistence.get_power_level.side_effect = _gen_get_power_level({
-            "u1": 5,
-            "u2": 10,
-        })
+        self.store.get_state_groups.return_value = {
+            group_name_1: old_state_1,
+            group_name_2: old_state_2,
+        }
 
-        self.persistence.get_unresolved_state_tree.return_value = (
-            (ReturnType([new_pdu], [old_pdu]), None)
-        )
+        yield self.state.annotate_state_groups(event)
 
-        is_new = yield self.state.handle_new_state(new_pdu)
+        self.assertEqual(len(event.old_state_events), 5)
 
-        self.assertTrue(is_new)
+        expected_new = event.old_state_events
+        expected_new[(event.type, event.state_key)] = event
 
-        self.persistence.get_unresolved_state_tree.assert_called_once_with(
-            new_pdu
+        self.assertEqual(
+            set([e.event_id for e in expected_new.values()]),
+            set([e.event_id for e in event.state_events.values()]),
         )
 
-        self.assertEqual(1, self.persistence.update_current_state.call_count)
-
-        self.assertFalse(self.replication.get_pdu.called)
-
-    @defer.inlineCallbacks
-    def test_new_event(self):
-        event = Mock()
-        event.event_id = "12123123@test"
+        self.assertIsNone(event.state_group)
 
-        state_pdu = new_fake_pdu("C", "test", "mem", "x", "A", 20)
+    def create_event(self, name=None, type=None, state_key=None):
+        self.event_id += 1
+        event_id = str(self.event_id)
 
-        snapshot = Mock()
-        snapshot.prev_state_pdu = state_pdu
-        event_id = "pdu_id@origin.com"
+        if not name:
+            if state_key is not None:
+                name = "<%s-%s>" % (type, state_key)
+            else:
+                name = "<%s>" % (type, )
 
-        def fill_out_prev_events(event):
-            event.prev_events = [event_id]
-            event.depth = 6
-        snapshot.fill_out_prev_events = fill_out_prev_events
+        event = Mock(name=name, spec=[])
+        event.type = type
 
-        yield self.state.handle_new_event(event, snapshot)
-
-        self.assertLess(5, event.depth)
-
-        self.assertEquals(1, len(event.prev_events))
-
-        prev_id = event.prev_events[0]
-
-        self.assertEqual(event_id, prev_id)
-
-        self.assertEqual(
-            encode_event_id(state_pdu.pdu_id, state_pdu.origin),
-            event.prev_state
-        )
+        if state_key is not None:
+            event.state_key = state_key
+        event.event_id = event_id
 
+        event.user_id = "@user_id:example.com"
+        event.room_id = "!room_id:example.com"
 
-def new_fake_pdu(pdu_id, context, pdu_type, state_key, prev_state_id,
-                 user_id, depth=0):
-    new_pdu = Pdu(
-        pdu_id=pdu_id,
-        pdu_type=pdu_type,
-        state_key=state_key,
-        user_id=user_id,
-        prev_state_id=prev_state_id,
-        origin="example.com",
-        context="context",
-        origin_server_ts=1405353060021,
-        depth=depth,
-        content_json="{}",
-        unrecognized_keys="{}",
-        outlier=True,
-        is_state=True,
-        prev_state_origin="example.com",
-        have_processed=True,
-        content={},
-    )
-
-    return new_pdu
+        return event