summary refs log tree commit diff
path: root/tests/server.py
blob: a12c3e3b9a095100d20b4ffde1304c05dc4e22d7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
# Copyright 2018-2021 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import hashlib
import json
import logging
import os
import os.path
import sqlite3
import time
import uuid
import warnings
from collections import deque
from io import SEEK_END, BytesIO
from typing import (
    Any,
    Awaitable,
    Callable,
    Dict,
    Iterable,
    List,
    MutableMapping,
    Optional,
    Sequence,
    Tuple,
    Type,
    TypeVar,
    Union,
    cast,
)
from unittest.mock import Mock

import attr
from typing_extensions import Deque, ParamSpec
from zope.interface import implementer

from twisted.internet import address, threads, udp
from twisted.internet._resolver import SimpleResolverComplexifier
from twisted.internet.defer import Deferred, fail, maybeDeferred, succeed
from twisted.internet.error import DNSLookupError
from twisted.internet.interfaces import (
    IAddress,
    IConnector,
    IConsumer,
    IHostnameResolver,
    IProducer,
    IProtocol,
    IPullProducer,
    IPushProducer,
    IReactorPluggableNameResolver,
    IReactorTime,
    IResolverSimple,
    ITransport,
)
from twisted.internet.protocol import ClientFactory, DatagramProtocol
from twisted.python import threadpool
from twisted.python.failure import Failure
from twisted.test.proto_helpers import AccumulatingProtocol, MemoryReactorClock
from twisted.web.http_headers import Headers
from twisted.web.resource import IResource
from twisted.web.server import Request, Site

from synapse.config.database import DatabaseConnectionConfig
from synapse.config.homeserver import HomeServerConfig
from synapse.events.presence_router import load_legacy_presence_router
from synapse.handlers.auth import load_legacy_password_auth_providers
from synapse.http.site import SynapseRequest
from synapse.logging.context import ContextResourceUsage
from synapse.module_api.callbacks.spamchecker_callbacks import load_legacy_spam_checkers
from synapse.module_api.callbacks.third_party_event_rules_callbacks import (
    load_legacy_third_party_event_rules,
)
from synapse.server import HomeServer
from synapse.storage import DataStore
from synapse.storage.database import LoggingDatabaseConnection
from synapse.storage.engines import PostgresEngine, create_engine
from synapse.storage.prepare_database import prepare_database
from synapse.types import ISynapseReactor, JsonDict
from synapse.util import Clock

from tests.utils import (
    LEAVE_DB,
    POSTGRES_BASE_DB,
    POSTGRES_HOST,
    POSTGRES_PASSWORD,
    POSTGRES_PORT,
    POSTGRES_USER,
    SQLITE_PERSIST_DB,
    USE_POSTGRES_FOR_TESTS,
    MockClock,
    default_config,
)

logger = logging.getLogger(__name__)

R = TypeVar("R")
P = ParamSpec("P")

# the type of thing that can be passed into `make_request` in the headers list
CustomHeaderType = Tuple[Union[str, bytes], Union[str, bytes]]

# A pre-prepared SQLite DB that is used as a template when creating new SQLite
# DB each test run. This dramatically speeds up test set up when using SQLite.
PREPPED_SQLITE_DB_CONN: Optional[LoggingDatabaseConnection] = None


class TimedOutException(Exception):
    """
    A web query timed out.
    """


@implementer(ITransport, IPushProducer, IConsumer)
@attr.s(auto_attribs=True)
class FakeChannel:
    """
    A fake Twisted Web Channel (the part that interfaces with the
    wire).

    See twisted.web.http.HTTPChannel.
    """

    site: Union[Site, "FakeSite"]
    _reactor: MemoryReactorClock
    result: dict = attr.Factory(dict)
    _ip: str = "127.0.0.1"
    _producer: Optional[Union[IPullProducer, IPushProducer]] = None
    resource_usage: Optional[ContextResourceUsage] = None
    _request: Optional[Request] = None

    @property
    def request(self) -> Request:
        assert self._request is not None
        return self._request

    @request.setter
    def request(self, request: Request) -> None:
        assert self._request is None
        self._request = request

    @property
    def json_body(self) -> JsonDict:
        body = json.loads(self.text_body)
        assert isinstance(body, dict)
        return body

    @property
    def json_list(self) -> List[JsonDict]:
        body = json.loads(self.text_body)
        assert isinstance(body, list)
        return body

    @property
    def text_body(self) -> str:
        """The body of the result, utf-8-decoded.

        Raises an exception if the request has not yet completed.
        """
        if not self.is_finished():
            raise Exception("Request not yet completed")
        return self.result["body"].decode("utf8")

    def is_finished(self) -> bool:
        """check if the response has been completely received"""
        return self.result.get("done", False)

    @property
    def code(self) -> int:
        if not self.result:
            raise Exception("No result yet.")
        return int(self.result["code"])

    @property
    def headers(self) -> Headers:
        if not self.result:
            raise Exception("No result yet.")
        h = Headers()
        for i in self.result["headers"]:
            h.addRawHeader(*i)
        return h

    def writeHeaders(
        self, version: bytes, code: bytes, reason: bytes, headers: Headers
    ) -> None:
        self.result["version"] = version
        self.result["code"] = code
        self.result["reason"] = reason
        self.result["headers"] = headers

    def write(self, data: bytes) -> None:
        assert isinstance(data, bytes), "Should be bytes! " + repr(data)

        if "body" not in self.result:
            self.result["body"] = b""

        self.result["body"] += data

    def writeSequence(self, data: Iterable[bytes]) -> None:
        for x in data:
            self.write(x)

    def loseConnection(self) -> None:
        self.unregisterProducer()
        self.transport.loseConnection()

    # Type ignore: mypy doesn't like the fact that producer isn't an IProducer.
    def registerProducer(self, producer: IProducer, streaming: bool) -> None:
        # TODO This should ensure that the IProducer is an IPushProducer or
        # IPullProducer, unfortunately twisted.protocols.basic.FileSender does
        # implement those, but doesn't declare it.
        self._producer = cast(Union[IPushProducer, IPullProducer], producer)
        self.producerStreaming = streaming

        def _produce() -> None:
            if self._producer:
                self._producer.resumeProducing()
                self._reactor.callLater(0.1, _produce)

        if not streaming:
            self._reactor.callLater(0.0, _produce)

    def unregisterProducer(self) -> None:
        if self._producer is None:
            return

        self._producer = None

    def stopProducing(self) -> None:
        if self._producer is not None:
            self._producer.stopProducing()

    def pauseProducing(self) -> None:
        raise NotImplementedError()

    def resumeProducing(self) -> None:
        raise NotImplementedError()

    def requestDone(self, _self: Request) -> None:
        self.result["done"] = True
        if isinstance(_self, SynapseRequest):
            assert _self.logcontext is not None
            self.resource_usage = _self.logcontext.get_resource_usage()

    def getPeer(self) -> IAddress:
        # We give an address so that getClientAddress/getClientIP returns a non null entry,
        # causing us to record the MAU
        return address.IPv4Address("TCP", self._ip, 3423)

    def getHost(self) -> IAddress:
        # this is called by Request.__init__ to configure Request.host.
        return address.IPv4Address("TCP", "127.0.0.1", 8888)

    def isSecure(self) -> bool:
        return False

    @property
    def transport(self) -> "FakeChannel":
        return self

    def await_result(self, timeout_ms: int = 1000) -> None:
        """
        Wait until the request is finished.
        """
        end_time = self._reactor.seconds() + timeout_ms / 1000.0
        self._reactor.run()

        while not self.is_finished():
            # If there's a producer, tell it to resume producing so we get content
            if self._producer:
                self._producer.resumeProducing()

            if self._reactor.seconds() > end_time:
                raise TimedOutException("Timed out waiting for request to finish.")

            self._reactor.advance(0.1)

    def extract_cookies(self, cookies: MutableMapping[str, str]) -> None:
        """Process the contents of any Set-Cookie headers in the response

        Any cookines found are added to the given dict
        """
        headers = self.headers.getRawHeaders("Set-Cookie")
        if not headers:
            return

        for h in headers:
            parts = h.split(";")
            k, v = parts[0].split("=", maxsplit=1)
            cookies[k] = v


class FakeSite:
    """
    A fake Twisted Web Site, with mocks of the extra things that
    Synapse adds.
    """

    server_version_string = b"1"
    site_tag = "test"
    access_logger = logging.getLogger("synapse.access.http.fake")

    def __init__(
        self,
        resource: IResource,
        reactor: IReactorTime,
        experimental_cors_msc3886: bool = False,
    ):
        """

        Args:
            resource: the resource to be used for rendering all requests
        """
        self._resource = resource
        self.reactor = reactor
        self.experimental_cors_msc3886 = experimental_cors_msc3886

    def getResourceFor(self, request: Request) -> IResource:
        return self._resource


def make_request(
    reactor: MemoryReactorClock,
    site: Union[Site, FakeSite],
    method: Union[bytes, str],
    path: Union[bytes, str],
    content: Union[bytes, str, JsonDict] = b"",
    access_token: Optional[str] = None,
    request: Type[Request] = SynapseRequest,
    shorthand: bool = True,
    federation_auth_origin: Optional[bytes] = None,
    content_is_form: bool = False,
    await_result: bool = True,
    custom_headers: Optional[Iterable[CustomHeaderType]] = None,
    client_ip: str = "127.0.0.1",
) -> FakeChannel:
    """
    Make a web request using the given method, path and content, and render it

    Returns the fake Channel object which records the response to the request.

    Args:
        reactor:
        site: The twisted Site to use to render the request
        method: The HTTP request method ("verb").
        path: The HTTP path, suitably URL encoded (e.g. escaped UTF-8 & spaces and such).
        content: The body of the request. JSON-encoded, if a str of bytes.
        access_token: The access token to add as authorization for the request.
        request: The request class to create.
        shorthand: Whether to try and be helpful and prefix the given URL
            with the usual REST API path, if it doesn't contain it.
        federation_auth_origin: if set to not-None, we will add a fake
            Authorization header pretenting to be the given server name.
        content_is_form: Whether the content is URL encoded form data. Adds the
            'Content-Type': 'application/x-www-form-urlencoded' header.
        await_result: whether to wait for the request to complete rendering. If true,
             will pump the reactor until the the renderer tells the channel the request
             is finished.
        custom_headers: (name, value) pairs to add as request headers
        client_ip: The IP to use as the requesting IP. Useful for testing
            ratelimiting.

    Returns:
        channel
    """
    if not isinstance(method, bytes):
        method = method.encode("ascii")

    if not isinstance(path, bytes):
        path = path.encode("ascii")

    # Decorate it to be the full path, if we're using shorthand
    if (
        shorthand
        and not path.startswith(b"/_matrix")
        and not path.startswith(b"/_synapse")
    ):
        if path.startswith(b"/"):
            path = path[1:]
        path = b"/_matrix/client/r0/" + path

    if not path.startswith(b"/"):
        path = b"/" + path

    if isinstance(content, dict):
        content = json.dumps(content).encode("utf8")
    if isinstance(content, str):
        content = content.encode("utf8")

    channel = FakeChannel(site, reactor, ip=client_ip)

    req = request(channel, site)
    channel.request = req

    req.content = BytesIO(content)
    # Twisted expects to be at the end of the content when parsing the request.
    req.content.seek(0, SEEK_END)

    # Old version of Twisted (<20.3.0) have issues with parsing x-www-form-urlencoded
    # bodies if the Content-Length header is missing
    req.requestHeaders.addRawHeader(
        b"Content-Length", str(len(content)).encode("ascii")
    )

    if access_token:
        req.requestHeaders.addRawHeader(
            b"Authorization", b"Bearer " + access_token.encode("ascii")
        )

    if federation_auth_origin is not None:
        req.requestHeaders.addRawHeader(
            b"Authorization",
            b"X-Matrix origin=%s,key=,sig=" % (federation_auth_origin,),
        )

    if content:
        if content_is_form:
            req.requestHeaders.addRawHeader(
                b"Content-Type", b"application/x-www-form-urlencoded"
            )
        else:
            # Assume the body is JSON
            req.requestHeaders.addRawHeader(b"Content-Type", b"application/json")

    if custom_headers:
        for k, v in custom_headers:
            req.requestHeaders.addRawHeader(k, v)

    req.parseCookies()
    req.requestReceived(method, path, b"1.1")

    if await_result:
        channel.await_result()

    return channel


# ISynapseReactor implies IReactorPluggableNameResolver, but explicitly
# marking this as an implementer of the latter seems to keep mypy-zope happier.
@implementer(IReactorPluggableNameResolver, ISynapseReactor)
class ThreadedMemoryReactorClock(MemoryReactorClock):
    """
    A MemoryReactorClock that supports callFromThread.
    """

    def __init__(self) -> None:
        self.threadpool = ThreadPool(self)

        self._tcp_callbacks: Dict[Tuple[str, int], Callable] = {}
        self._udp: List[udp.Port] = []
        self.lookups: Dict[str, str] = {}
        self._thread_callbacks: Deque[Callable[..., R]] = deque()

        lookups = self.lookups

        @implementer(IResolverSimple)
        class FakeResolver:
            def getHostByName(
                self, name: str, timeout: Optional[Sequence[int]] = None
            ) -> "Deferred[str]":
                if name not in lookups:
                    return fail(DNSLookupError("OH NO: unknown %s" % (name,)))
                return succeed(lookups[name])

        self.nameResolver = SimpleResolverComplexifier(FakeResolver())
        super().__init__()

    def installNameResolver(self, resolver: IHostnameResolver) -> IHostnameResolver:
        raise NotImplementedError()

    def listenUDP(
        self,
        port: int,
        protocol: DatagramProtocol,
        interface: str = "",
        maxPacketSize: int = 8196,
    ) -> udp.Port:
        p = udp.Port(port, protocol, interface, maxPacketSize, self)
        p.startListening()
        self._udp.append(p)
        return p

    def callFromThread(
        self, callable: Callable[..., Any], *args: object, **kwargs: object
    ) -> None:
        """
        Make the callback fire in the next reactor iteration.
        """
        cb = lambda: callable(*args, **kwargs)
        # it's not safe to call callLater() here, so we append the callback to a
        # separate queue.
        self._thread_callbacks.append(cb)

    def callInThread(
        self, callable: Callable[..., Any], *args: object, **kwargs: object
    ) -> None:
        raise NotImplementedError()

    def suggestThreadPoolSize(self, size: int) -> None:
        raise NotImplementedError()

    def getThreadPool(self) -> "threadpool.ThreadPool":
        # Cast to match super-class.
        return cast(threadpool.ThreadPool, self.threadpool)

    def add_tcp_client_callback(
        self, host: str, port: int, callback: Callable[[], None]
    ) -> None:
        """Add a callback that will be invoked when we receive a connection
        attempt to the given IP/port using `connectTCP`.

        Note that the callback gets run before we return the connection to the
        client, which means callbacks cannot block while waiting for writes.
        """
        self._tcp_callbacks[(host, port)] = callback

    def connectTCP(
        self,
        host: str,
        port: int,
        factory: ClientFactory,
        timeout: float = 30,
        bindAddress: Optional[Tuple[str, int]] = None,
    ) -> IConnector:
        """Fake L{IReactorTCP.connectTCP}."""

        conn = super().connectTCP(
            host, port, factory, timeout=timeout, bindAddress=None
        )

        callback = self._tcp_callbacks.get((host, port))
        if callback:
            callback()

        return conn

    def advance(self, amount: float) -> None:
        # first advance our reactor's time, and run any "callLater" callbacks that
        # makes ready
        super().advance(amount)

        # now run any "callFromThread" callbacks
        while True:
            try:
                callback = self._thread_callbacks.popleft()
            except IndexError:
                break
            callback()

            # check for more "callLater" callbacks added by the thread callback
            # This isn't required in a regular reactor, but it ends up meaning that
            # our database queries can complete in a single call to `advance` [1] which
            # simplifies tests.
            #
            # [1]: we replace the threadpool backing the db connection pool with a
            # mock ThreadPool which doesn't really use threads; but we still use
            # reactor.callFromThread to feed results back from the db functions to the
            # main thread.
            super().advance(0)


class ThreadPool:
    """
    Threadless thread pool.

    See twisted.python.threadpool.ThreadPool
    """

    def __init__(self, reactor: IReactorTime):
        self._reactor = reactor

    def start(self) -> None:
        pass

    def stop(self) -> None:
        pass

    def callInThreadWithCallback(
        self,
        onResult: Callable[[bool, Union[Failure, R]], None],
        function: Callable[P, R],
        *args: P.args,
        **kwargs: P.kwargs,
    ) -> "Deferred[None]":
        def _(res: Any) -> None:
            if isinstance(res, Failure):
                onResult(False, res)
            else:
                onResult(True, res)

        d: "Deferred[None]" = Deferred()
        d.addCallback(lambda x: function(*args, **kwargs))
        d.addBoth(_)
        self._reactor.callLater(0, d.callback, True)
        return d


def _make_test_homeserver_synchronous(server: HomeServer) -> None:
    """
    Make the given test homeserver's database interactions synchronous.
    """

    clock = server.get_clock()

    for database in server.get_datastores().databases:
        pool = database._db_pool

        def runWithConnection(
            func: Callable[..., R], *args: Any, **kwargs: Any
        ) -> Awaitable[R]:
            return threads.deferToThreadPool(
                pool._reactor,
                pool.threadpool,
                pool._runWithConnection,
                func,
                *args,
                **kwargs,
            )

        def runInteraction(
            desc: str, func: Callable[..., R], *args: Any, **kwargs: Any
        ) -> Awaitable[R]:
            return threads.deferToThreadPool(
                pool._reactor,
                pool.threadpool,
                pool._runInteraction,
                desc,
                func,
                *args,
                **kwargs,
            )

        pool.runWithConnection = runWithConnection  # type: ignore[assignment]
        pool.runInteraction = runInteraction  # type: ignore[assignment]
        # Replace the thread pool with a threadless 'thread' pool
        pool.threadpool = ThreadPool(clock._reactor)
        pool.running = True

    # We've just changed the Databases to run DB transactions on the same
    # thread, so we need to disable the dedicated thread behaviour.
    server.get_datastores().main.USE_DEDICATED_DB_THREADS_FOR_EVENT_FETCHING = False


def get_clock() -> Tuple[ThreadedMemoryReactorClock, Clock]:
    clock = ThreadedMemoryReactorClock()
    hs_clock = Clock(clock)
    return clock, hs_clock


@implementer(ITransport)
@attr.s(cmp=False, auto_attribs=True)
class FakeTransport:
    """
    A twisted.internet.interfaces.ITransport implementation which sends all its data
    straight into an IProtocol object: it exists to connect two IProtocols together.

    To use it, instantiate it with the receiving IProtocol, and then pass it to the
    sending IProtocol's makeConnection method:

        server = HTTPChannel()
        client.makeConnection(FakeTransport(server, self.reactor))

    If you want bidirectional communication, you'll need two instances.
    """

    other: IProtocol
    """The Protocol object which will receive any data written to this transport.
    """

    _reactor: IReactorTime
    """Test reactor
    """

    _protocol: Optional[IProtocol] = None
    """The Protocol which is producing data for this transport. Optional, but if set
    will get called back for connectionLost() notifications etc.
    """

    _peer_address: IAddress = attr.Factory(
        lambda: address.IPv4Address("TCP", "127.0.0.1", 5678)
    )
    """The value to be returned by getPeer"""

    _host_address: IAddress = attr.Factory(
        lambda: address.IPv4Address("TCP", "127.0.0.1", 1234)
    )
    """The value to be returned by getHost"""

    disconnecting = False
    disconnected = False
    connected = True
    buffer: bytes = b""
    producer: Optional[IPushProducer] = None
    autoflush: bool = True

    def getPeer(self) -> IAddress:
        return self._peer_address

    def getHost(self) -> IAddress:
        return self._host_address

    def loseConnection(self) -> None:
        if not self.disconnecting:
            logger.info("FakeTransport: loseConnection()")
            self.disconnecting = True
            if self._protocol:
                self._protocol.connectionLost(
                    Failure(RuntimeError("FakeTransport.loseConnection()"))
                )

            # if we still have data to write, delay until that is done
            if self.buffer:
                logger.info(
                    "FakeTransport: Delaying disconnect until buffer is flushed"
                )
            else:
                self.connected = False
                self.disconnected = True

    def abortConnection(self) -> None:
        logger.info("FakeTransport: abortConnection()")

        if not self.disconnecting:
            self.disconnecting = True
            if self._protocol:
                self._protocol.connectionLost(None)  # type: ignore[arg-type]

        self.disconnected = True

    def pauseProducing(self) -> None:
        if not self.producer:
            return

        self.producer.pauseProducing()

    def resumeProducing(self) -> None:
        if not self.producer:
            return
        self.producer.resumeProducing()

    def unregisterProducer(self) -> None:
        if not self.producer:
            return

        self.producer = None

    def registerProducer(self, producer: IPushProducer, streaming: bool) -> None:
        self.producer = producer
        self.producerStreaming = streaming

        def _produce() -> None:
            if not self.producer:
                # we've been unregistered
                return
            # some implementations of IProducer (for example, FileSender)
            # don't return a deferred.
            d = maybeDeferred(self.producer.resumeProducing)
            d.addCallback(lambda x: self._reactor.callLater(0.1, _produce))

        if not streaming:
            self._reactor.callLater(0.0, _produce)

    def write(self, byt: bytes) -> None:
        if self.disconnecting:
            raise Exception("Writing to disconnecting FakeTransport")

        self.buffer = self.buffer + byt

        # always actually do the write asynchronously. Some protocols (notably the
        # TLSMemoryBIOProtocol) get very confused if a read comes back while they are
        # still doing a write. Doing a callLater here breaks the cycle.
        if self.autoflush:
            self._reactor.callLater(0.0, self.flush)

    def writeSequence(self, seq: Iterable[bytes]) -> None:
        for x in seq:
            self.write(x)

    def flush(self, maxbytes: Optional[int] = None) -> None:
        if not self.buffer:
            # nothing to do. Don't write empty buffers: it upsets the
            # TLSMemoryBIOProtocol
            return

        if self.disconnected:
            return

        if maxbytes is not None:
            to_write = self.buffer[:maxbytes]
        else:
            to_write = self.buffer

        logger.info("%s->%s: %s", self._protocol, self.other, to_write)

        try:
            self.other.dataReceived(to_write)
        except Exception as e:
            logger.exception("Exception writing to protocol: %s", e)
            return

        self.buffer = self.buffer[len(to_write) :]
        if self.buffer and self.autoflush:
            self._reactor.callLater(0.0, self.flush)

        if not self.buffer and self.disconnecting:
            logger.info("FakeTransport: Buffer now empty, completing disconnect")
            self.disconnected = True


def connect_client(
    reactor: ThreadedMemoryReactorClock, client_id: int
) -> Tuple[IProtocol, AccumulatingProtocol]:
    """
    Connect a client to a fake TCP transport.

    Args:
        reactor
        factory: The connecting factory to build.
    """
    factory = reactor.tcpClients.pop(client_id)[2]
    client = factory.buildProtocol(None)
    server = AccumulatingProtocol()
    server.makeConnection(FakeTransport(client, reactor))
    client.makeConnection(FakeTransport(server, reactor))

    return client, server


class TestHomeServer(HomeServer):
    DATASTORE_CLASS = DataStore  # type: ignore[assignment]


def setup_test_homeserver(
    cleanup_func: Callable[[Callable[[], None]], None],
    name: str = "test",
    config: Optional[HomeServerConfig] = None,
    reactor: Optional[ISynapseReactor] = None,
    homeserver_to_use: Type[HomeServer] = TestHomeServer,
    **kwargs: Any,
) -> HomeServer:
    """
    Setup a homeserver suitable for running tests against.  Keyword arguments
    are passed to the Homeserver constructor.

    If no datastore is supplied, one is created and given to the homeserver.

    Args:
        cleanup_func : The function used to register a cleanup routine for
                       after the test.

    Calling this method directly is deprecated: you should instead derive from
    HomeserverTestCase.
    """
    if reactor is None:
        from twisted.internet import reactor as _reactor

        reactor = cast(ISynapseReactor, _reactor)

    if config is None:
        config = default_config(name, parse=True)

    config.caches.resize_all_caches()

    if "clock" not in kwargs:
        kwargs["clock"] = MockClock()

    if USE_POSTGRES_FOR_TESTS:
        test_db = "synapse_test_%s" % uuid.uuid4().hex

        database_config = {
            "name": "psycopg2",
            "args": {
                "database": test_db,
                "host": POSTGRES_HOST,
                "password": POSTGRES_PASSWORD,
                "user": POSTGRES_USER,
                "port": POSTGRES_PORT,
                "cp_min": 1,
                "cp_max": 5,
            },
        }
    else:
        if SQLITE_PERSIST_DB:
            # The current working directory is in _trial_temp, so this gets created within that directory.
            test_db_location = os.path.abspath("test.db")
            logger.debug("Will persist db to %s", test_db_location)
            # Ensure each test gets a clean database.
            try:
                os.remove(test_db_location)
            except FileNotFoundError:
                pass
            else:
                logger.debug("Removed existing DB at %s", test_db_location)
        else:
            test_db_location = ":memory:"

        database_config = {
            "name": "sqlite3",
            "args": {"database": test_db_location, "cp_min": 1, "cp_max": 1},
        }

        # Check if we have set up a DB that we can use as a template.
        global PREPPED_SQLITE_DB_CONN
        if PREPPED_SQLITE_DB_CONN is None:
            temp_engine = create_engine(database_config)
            PREPPED_SQLITE_DB_CONN = LoggingDatabaseConnection(
                sqlite3.connect(":memory:"), temp_engine, "PREPPED_CONN"
            )

            database = DatabaseConnectionConfig("master", database_config)
            config.database.databases = [database]
            prepare_database(
                PREPPED_SQLITE_DB_CONN, create_engine(database_config), config
            )

        database_config["_TEST_PREPPED_CONN"] = PREPPED_SQLITE_DB_CONN

    if "db_txn_limit" in kwargs:
        database_config["txn_limit"] = kwargs["db_txn_limit"]

    database = DatabaseConnectionConfig("master", database_config)
    config.database.databases = [database]

    db_engine = create_engine(database.config)

    # Create the database before we actually try and connect to it, based off
    # the template database we generate in setupdb()
    if isinstance(db_engine, PostgresEngine):
        import psycopg2.extensions

        db_conn = db_engine.module.connect(
            database=POSTGRES_BASE_DB,
            user=POSTGRES_USER,
            host=POSTGRES_HOST,
            port=POSTGRES_PORT,
            password=POSTGRES_PASSWORD,
        )
        assert isinstance(db_conn, psycopg2.extensions.connection)
        db_conn.autocommit = True
        cur = db_conn.cursor()
        cur.execute("DROP DATABASE IF EXISTS %s;" % (test_db,))
        cur.execute(
            "CREATE DATABASE %s WITH TEMPLATE %s;" % (test_db, POSTGRES_BASE_DB)
        )
        cur.close()
        db_conn.close()

    hs = homeserver_to_use(
        name,
        config=config,
        version_string="Synapse/tests",
        reactor=reactor,
    )

    # Install @cache_in_self attributes
    for key, val in kwargs.items():
        setattr(hs, "_" + key, val)

    # Mock TLS
    hs.tls_server_context_factory = Mock()

    hs.setup()
    if homeserver_to_use == TestHomeServer:
        hs.setup_background_tasks()

    if isinstance(db_engine, PostgresEngine):
        database_pool = hs.get_datastores().databases[0]

        # We need to do cleanup on PostgreSQL
        def cleanup() -> None:
            import psycopg2
            import psycopg2.extensions

            # Close all the db pools
            database_pool._db_pool.close()

            dropped = False

            # Drop the test database
            db_conn = db_engine.module.connect(
                database=POSTGRES_BASE_DB,
                user=POSTGRES_USER,
                host=POSTGRES_HOST,
                port=POSTGRES_PORT,
                password=POSTGRES_PASSWORD,
            )
            assert isinstance(db_conn, psycopg2.extensions.connection)
            db_conn.autocommit = True
            cur = db_conn.cursor()

            # Try a few times to drop the DB. Some things may hold on to the
            # database for a few more seconds due to flakiness, preventing
            # us from dropping it when the test is over. If we can't drop
            # it, warn and move on.
            for _ in range(5):
                try:
                    cur.execute("DROP DATABASE IF EXISTS %s;" % (test_db,))
                    db_conn.commit()
                    dropped = True
                except psycopg2.OperationalError as e:
                    warnings.warn(
                        "Couldn't drop old db: " + str(e),
                        category=UserWarning,
                        stacklevel=2,
                    )
                    time.sleep(0.5)

            cur.close()
            db_conn.close()

            if not dropped:
                warnings.warn(
                    "Failed to drop old DB.",
                    category=UserWarning,
                    stacklevel=2,
                )

        if not LEAVE_DB:
            # Register the cleanup hook
            cleanup_func(cleanup)

    # bcrypt is far too slow to be doing in unit tests
    # Need to let the HS build an auth handler and then mess with it
    # because AuthHandler's constructor requires the HS, so we can't make one
    # beforehand and pass it in to the HS's constructor (chicken / egg)
    async def hash(p: str) -> str:
        return hashlib.md5(p.encode("utf8")).hexdigest()

    hs.get_auth_handler().hash = hash  # type: ignore[assignment]

    async def validate_hash(p: str, h: str) -> bool:
        return hashlib.md5(p.encode("utf8")).hexdigest() == h

    hs.get_auth_handler().validate_hash = validate_hash  # type: ignore[assignment]

    # Make the threadpool and database transactions synchronous for testing.
    _make_test_homeserver_synchronous(hs)

    # Load any configured modules into the homeserver
    module_api = hs.get_module_api()
    for module, module_config in hs.config.modules.loaded_modules:
        module(config=module_config, api=module_api)

    load_legacy_spam_checkers(hs)
    load_legacy_third_party_event_rules(hs)
    load_legacy_presence_router(hs)
    load_legacy_password_auth_providers(hs)

    return hs