view tests/test-wireproto-serverreactor.py @ 39788:ae531f5e583c

testing: add interface unit tests for file storage

Our strategy for supporting alternate storage backends is to define
interfaces for everything then "code to the interface."

We already have interfaces for various primitives, including file
and manifest storage.

What we don't have is generic unit tests for those interfaces. Up
to this point we've been relying on high-level integration tests
(mainly in the form of existing .t tests) to test alternate storage
backends. And my experience with developing the "simple store" test
extension is that such testing is very tedious: it takes several
minutes to run all tests and when you find a failure, it is often
non-trivial to debug.

This commit starts to change that.

This commit introduces the mercurial.testing.storage module. It
contains testing code for storage. Currently, it defines some
unittest.TestCase classes for testing the file storage interfaces.
It also defines some factory functions that allow a caller to easily
spawn a custom TestCase "bound" to a specific file storage backend
implementation.

A new .py test has been added. It simply defines a callable to produce
filelog and transaction instances on demand and then "registers" the
various test classes so the filelog class can be tested with the
storage interface unit tests.

As part of writing the tests, I identified a couple of apparent
bugs in revlog.py and filelog.py! These are tracked with inline
TODO comments.

Writing the tests makes it more obvious where the storage interface
is lacking. For example, we raise either IndexError or
error.LookupError for missing revisions depending on whether we
use an integer revision or a node. Also, we raise error.RevlogError
in various places when we should be raising a storage-agnostic
error type.

The storage interfaces are currently far from perfect and there is much
work to be done to improve them. But at least with this commit we
finally have the start of unit tests that can be used to "qualify"
the behavior of a storage backend. And when implementing and debugging
new storage backends, we now have an obvious place to define new
tests and have obvious places to insert breakpoints to facilitate
debugging. This should be invaluable when implementing new storage
backends.

I added the mercurial.testing package because these interface
conformance tests are generic and need to be usable by all storage
backends. Having the code live in tests/ would make it difficult for
storage backends implemented in extensions to test their interface
conformance. First, it would require obtaining a copy of Mercurial's
storage test code in order to test. Second, it would make testing
against multiple Mercurial versions difficult, as you would need to
import N copies of the storage testing code in order to achieve test
coverage. By making the test code part of the Mercurial distribution
itself, extensions can `import mercurial.testing.*` to access and run
the test code. The test will run against whatever Mercurial version
is active.

FWIW I've always wanted to move parts of run-tests.py into the
mercurial.* package to make the testing story simpler (e.g. imagine an
`hg debugruntests` command that could invoke the test harness). While I
have no plans to do that in the near future, establishing the
mercurial.testing package does provide a natural home for that code
should someone do this in the future.

Differential Revision: https://phab.mercurial-scm.org/D4650

from __future__ import absolute_import, print_function

import unittest

from mercurial.thirdparty import (
    cbor,
)
from mercurial import (
    util,
    wireprotoframing as framing,
)

ffs = framing.makeframefromhumanstring

OK = cbor.dumps({b'status': b'ok'})

def makereactor(deferoutput=False):
    return framing.serverreactor(deferoutput=deferoutput)

def sendframes(reactor, gen):
    """Send a generator of frame bytearray to a reactor.

    Emits a generator of results from ``onframerecv()`` calls.
    """
    for frame in gen:
        header = framing.parseheader(frame)
        payload = frame[framing.FRAME_HEADER_SIZE:]
        assert len(payload) == header.length

        yield reactor.onframerecv(framing.frame(header.requestid,
                                                header.streamid,
                                                header.streamflags,
                                                header.typeid,
                                                header.flags,
                                                payload))

def sendcommandframes(reactor, stream, rid, cmd, args, datafh=None):
    """Generate frames to run a command and send them to a reactor."""
    return sendframes(reactor,
                      framing.createcommandframes(stream, rid, cmd, args,
                                                  datafh))


class ServerReactorTests(unittest.TestCase):
    def _sendsingleframe(self, reactor, f):
        results = list(sendframes(reactor, [f]))
        self.assertEqual(len(results), 1)

        return results[0]

    def assertaction(self, res, expected):
        self.assertIsInstance(res, tuple)
        self.assertEqual(len(res), 2)
        self.assertIsInstance(res[1], dict)
        self.assertEqual(res[0], expected)

    def assertframesequal(self, frames, framestrings):
        expected = [ffs(s) for s in framestrings]
        self.assertEqual(list(frames), expected)

    def test1framecommand(self):
        """Receiving a command in a single frame yields request to run it."""
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(sendcommandframes(reactor, stream, 1, b'mycommand', {}))
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')
        self.assertEqual(results[0][1], {
            b'requestid': 1,
            b'command': b'mycommand',
            b'args': {},
            b'data': None,
        })

        result = reactor.oninputeof()
        self.assertaction(result, b'noop')

    def test1argument(self):
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(sendcommandframes(reactor, stream, 41, b'mycommand',
                                         {b'foo': b'bar'}))
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')
        self.assertEqual(results[0][1], {
            b'requestid': 41,
            b'command': b'mycommand',
            b'args': {b'foo': b'bar'},
            b'data': None,
        })

    def testmultiarguments(self):
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(sendcommandframes(reactor, stream, 1, b'mycommand',
                                         {b'foo': b'bar', b'biz': b'baz'}))
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')
        self.assertEqual(results[0][1], {
            b'requestid': 1,
            b'command': b'mycommand',
            b'args': {b'foo': b'bar', b'biz': b'baz'},
            b'data': None,
        })

    def testsimplecommanddata(self):
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(sendcommandframes(reactor, stream, 1, b'mycommand', {},
                                         util.bytesio(b'data!')))
        self.assertEqual(len(results), 2)
        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'runcommand')
        self.assertEqual(results[1][1], {
            b'requestid': 1,
            b'command': b'mycommand',
            b'args': {},
            b'data': b'data!',
        })

    def testmultipledataframes(self):
        frames = [
            ffs(b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'mycommand'}"),
            ffs(b'1 1 0 command-data continuation data1'),
            ffs(b'1 1 0 command-data continuation data2'),
            ffs(b'1 1 0 command-data eos data3'),
        ]

        reactor = makereactor()
        results = list(sendframes(reactor, frames))
        self.assertEqual(len(results), 4)
        for i in range(3):
            self.assertaction(results[i], b'wantframe')
        self.assertaction(results[3], b'runcommand')
        self.assertEqual(results[3][1], {
            b'requestid': 1,
            b'command': b'mycommand',
            b'args': {},
            b'data': b'data1data2data3',
        })

    def testargumentanddata(self):
        frames = [
            ffs(b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'command', b'args': {b'key': b'val',"
                b"b'foo': b'bar'}}"),
            ffs(b'1 1 0 command-data continuation value1'),
            ffs(b'1 1 0 command-data eos value2'),
        ]

        reactor = makereactor()
        results = list(sendframes(reactor, frames))

        self.assertaction(results[-1], b'runcommand')
        self.assertEqual(results[-1][1], {
            b'requestid': 1,
            b'command': b'command',
            b'args': {
                b'key': b'val',
                b'foo': b'bar',
            },
            b'data': b'value1value2',
        })

    def testnewandcontinuation(self):
        result = self._sendsingleframe(makereactor(),
            ffs(b'1 1 stream-begin command-request new|continuation '))
        self.assertaction(result, b'error')
        self.assertEqual(result[1], {
            b'message': b'received command request frame with both new and '
                        b'continuation flags set',
        })

    def testneithernewnorcontinuation(self):
        result = self._sendsingleframe(makereactor(),
            ffs(b'1 1 stream-begin command-request 0 '))
        self.assertaction(result, b'error')
        self.assertEqual(result[1], {
            b'message': b'received command request frame with neither new nor '
                        b'continuation flags set',
        })

    def testunexpectedcommanddata(self):
        """Command data frame when not running a command is an error."""
        result = self._sendsingleframe(makereactor(),
            ffs(b'1 1 stream-begin command-data 0 ignored'))
        self.assertaction(result, b'error')
        self.assertEqual(result[1], {
            b'message': b'expected command request frame; got 2',
        })

    def testunexpectedcommanddatareceiving(self):
        """Same as above except the command is receiving."""
        results = list(sendframes(makereactor(), [
            ffs(b'1 1 stream-begin command-request new|more '
                b"cbor:{b'name': b'ignored'}"),
            ffs(b'1 1 0 command-data eos ignored'),
        ]))

        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'error')
        self.assertEqual(results[1][1], {
            b'message': b'received command data frame for request that is not '
                        b'expecting data: 1',
        })

    def testconflictingrequestidallowed(self):
        """Multiple fully serviced commands with same request ID is allowed."""
        reactor = makereactor()
        results = []
        outstream = reactor.makeoutputstream()
        results.append(self._sendsingleframe(
            reactor, ffs(b'1 1 stream-begin command-request new '
                         b"cbor:{b'name': b'command'}")))
        result = reactor.oncommandresponseready(outstream, 1, b'response1')
        self.assertaction(result, b'sendframes')
        list(result[1][b'framegen'])
        results.append(self._sendsingleframe(
            reactor, ffs(b'1 1 stream-begin command-request new '
                         b"cbor:{b'name': b'command'}")))
        result = reactor.oncommandresponseready(outstream, 1, b'response2')
        self.assertaction(result, b'sendframes')
        list(result[1][b'framegen'])
        results.append(self._sendsingleframe(
            reactor, ffs(b'1 1 stream-begin command-request new '
                         b"cbor:{b'name': b'command'}")))
        result = reactor.oncommandresponseready(outstream, 1, b'response3')
        self.assertaction(result, b'sendframes')
        list(result[1][b'framegen'])

        for i in range(3):
            self.assertaction(results[i], b'runcommand')
            self.assertEqual(results[i][1], {
                b'requestid': 1,
                b'command': b'command',
                b'args': {},
                b'data': None,
            })

    def testconflictingrequestid(self):
        """Request ID for new command matching in-flight command is illegal."""
        results = list(sendframes(makereactor(), [
            ffs(b'1 1 stream-begin command-request new|more '
                b"cbor:{b'name': b'command'}"),
            ffs(b'1 1 0 command-request new '
                b"cbor:{b'name': b'command1'}"),
        ]))

        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'error')
        self.assertEqual(results[1][1], {
            b'message': b'request with ID 1 already received',
        })

    def testinterleavedcommands(self):
        cbor1 = cbor.dumps({
            b'name': b'command1',
            b'args': {
                b'foo': b'bar',
                b'key1': b'val',
            }
        }, canonical=True)
        cbor3 = cbor.dumps({
            b'name': b'command3',
            b'args': {
                b'biz': b'baz',
                b'key': b'val',
            },
        }, canonical=True)

        results = list(sendframes(makereactor(), [
            ffs(b'1 1 stream-begin command-request new|more %s' % cbor1[0:6]),
            ffs(b'3 1 0 command-request new|more %s' % cbor3[0:10]),
            ffs(b'1 1 0 command-request continuation|more %s' % cbor1[6:9]),
            ffs(b'3 1 0 command-request continuation|more %s' % cbor3[10:13]),
            ffs(b'3 1 0 command-request continuation %s' % cbor3[13:]),
            ffs(b'1 1 0 command-request continuation %s' % cbor1[9:]),
        ]))

        self.assertEqual([t[0] for t in results], [
            b'wantframe',
            b'wantframe',
            b'wantframe',
            b'wantframe',
            b'runcommand',
            b'runcommand',
        ])

        self.assertEqual(results[4][1], {
            b'requestid': 3,
            b'command': b'command3',
            b'args': {b'biz': b'baz', b'key': b'val'},
            b'data': None,
        })
        self.assertEqual(results[5][1], {
            b'requestid': 1,
            b'command': b'command1',
            b'args': {b'foo': b'bar', b'key1': b'val'},
            b'data': None,
        })

    def testmissingcommanddataframe(self):
        # The reactor doesn't currently handle partially received commands.
        # So this test is failing to do anything with request 1.
        frames = [
            ffs(b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'command1'}"),
            ffs(b'3 1 0 command-request new '
                b"cbor:{b'name': b'command2'}"),
        ]
        results = list(sendframes(makereactor(), frames))
        self.assertEqual(len(results), 2)
        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'runcommand')

    def testmissingcommanddataframeflags(self):
        frames = [
            ffs(b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'command1'}"),
            ffs(b'1 1 0 command-data 0 data'),
        ]
        results = list(sendframes(makereactor(), frames))
        self.assertEqual(len(results), 2)
        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'error')
        self.assertEqual(results[1][1], {
            b'message': b'command data frame without flags',
        })

    def testframefornonreceivingrequest(self):
        """Receiving a frame for a command that is not receiving is illegal."""
        results = list(sendframes(makereactor(), [
            ffs(b'1 1 stream-begin command-request new '
                b"cbor:{b'name': b'command1'}"),
            ffs(b'3 1 0 command-request new|have-data '
                b"cbor:{b'name': b'command3'}"),
            ffs(b'5 1 0 command-data eos ignored'),
        ]))
        self.assertaction(results[2], b'error')
        self.assertEqual(results[2][1], {
            b'message': b'received frame for request that is not receiving: 5',
        })

    def testsimpleresponse(self):
        """Bytes response to command sends result frames."""
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'mycommand', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponseready(outstream, 1, b'response')
        self.assertaction(result, b'sendframes')
        self.assertframesequal(result[1][b'framegen'], [
            b'1 2 stream-begin command-response eos %sresponse' % OK,
        ])

    def testmultiframeresponse(self):
        """Bytes response spanning multiple frames is handled."""
        first = b'x' * framing.DEFAULT_MAX_FRAME_SIZE
        second = b'y' * 100

        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'mycommand', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponseready(outstream, 1, first + second)
        self.assertaction(result, b'sendframes')
        self.assertframesequal(result[1][b'framegen'], [
            b'1 2 stream-begin command-response continuation %s' % OK,
            b'1 2 0 command-response continuation %s' % first,
            b'1 2 0 command-response eos %s' % second,
        ])

    def testservererror(self):
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'mycommand', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.onservererror(outstream, 1, b'some message')
        self.assertaction(result, b'sendframes')
        self.assertframesequal(result[1][b'framegen'], [
            b"1 2 stream-begin error-response 0 "
            b"cbor:{b'type': b'server', "
            b"b'message': [{b'msg': b'some message'}]}",
        ])

    def test1commanddeferresponse(self):
        """Responses when in deferred output mode are delayed until EOF."""
        reactor = makereactor(deferoutput=True)
        instream = framing.stream(1)
        results = list(sendcommandframes(reactor, instream, 1, b'mycommand',
                                         {}))
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponseready(outstream, 1, b'response')
        self.assertaction(result, b'noop')
        result = reactor.oninputeof()
        self.assertaction(result, b'sendframes')
        self.assertframesequal(result[1][b'framegen'], [
            b'1 2 stream-begin command-response eos %sresponse' % OK,
        ])

    def testmultiplecommanddeferresponse(self):
        reactor = makereactor(deferoutput=True)
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        list(sendcommandframes(reactor, instream, 3, b'command2', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponseready(outstream, 1, b'response1')
        self.assertaction(result, b'noop')
        result = reactor.oncommandresponseready(outstream, 3, b'response2')
        self.assertaction(result, b'noop')
        result = reactor.oninputeof()
        self.assertaction(result, b'sendframes')
        self.assertframesequal(result[1][b'framegen'], [
            b'1 2 stream-begin command-response eos %sresponse1' % OK,
            b'3 2 0 command-response eos %sresponse2' % OK,
        ])

    def testrequestidtracking(self):
        reactor = makereactor(deferoutput=True)
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        list(sendcommandframes(reactor, instream, 3, b'command2', {}))
        list(sendcommandframes(reactor, instream, 5, b'command3', {}))

        # Register results for commands out of order.
        outstream = reactor.makeoutputstream()
        reactor.oncommandresponseready(outstream, 3, b'response3')
        reactor.oncommandresponseready(outstream, 1, b'response1')
        reactor.oncommandresponseready(outstream, 5, b'response5')

        result = reactor.oninputeof()
        self.assertaction(result, b'sendframes')
        self.assertframesequal(result[1][b'framegen'], [
            b'3 2 stream-begin command-response eos %sresponse3' % OK,
            b'1 2 0 command-response eos %sresponse1' % OK,
            b'5 2 0 command-response eos %sresponse5' % OK,
        ])

    def testduplicaterequestonactivecommand(self):
        """Receiving a request ID that matches a request that isn't finished."""
        reactor = makereactor()
        stream = framing.stream(1)
        list(sendcommandframes(reactor, stream, 1, b'command1', {}))
        results = list(sendcommandframes(reactor, stream, 1, b'command1', {}))

        self.assertaction(results[0], b'error')
        self.assertEqual(results[0][1], {
            b'message': b'request with ID 1 is already active',
        })

    def testduplicaterequestonactivecommandnosend(self):
        """Same as above but we've registered a response but haven't sent it."""
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        outstream = reactor.makeoutputstream()
        reactor.oncommandresponseready(outstream, 1, b'response')

        # We've registered the response but haven't sent it. From the
        # perspective of the reactor, the command is still active.

        results = list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        self.assertaction(results[0], b'error')
        self.assertEqual(results[0][1], {
            b'message': b'request with ID 1 is already active',
        })

    def testduplicaterequestaftersend(self):
        """We can use a duplicate request ID after we've sent the response."""
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        outstream = reactor.makeoutputstream()
        res = reactor.oncommandresponseready(outstream, 1, b'response')
        list(res[1][b'framegen'])

        results = list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        self.assertaction(results[0], b'runcommand')

if __name__ == '__main__':
    import silenttestrunner
    silenttestrunner.main(__name__)