view tests/test-verify-repo-operations.py @ 35569:964212780daf

rust: implementation of `hg` This commit provides a mostly-working implementation of the `hg` script in Rust along with scaffolding to support Rust in the repository. If you are familiar with Rust, the contents of the added rust/ directory should be pretty straightforward. We create an "hgcli" package that implements a binary application to run Mercurial. The output of this package is an "hg" binary. Our Rust `hg` (henceforth "rhg") essentially is a port of the existing `hg` Python script. The main difference is the creation of the embedded CPython interpreter is handled by the binary itself instead of relying on the shebang. In that sense, rhg is more similar to the "exe wrapper" we currently use on Windows. However, unlike the exe wrapper, rhg does not call the `hg` Python script. Instead, it uses the CPython APIs to import mercurial modules and call appropriate functions. The amount of code here is surprisingly small. It is my intent to replace the existing C-based exe wrapper with rhg. Preferably in the next Mercurial release. This should be achievable - at least for some Mercurial distributions. The future/timeline for rhg on other platforms is less clear. We already ship a hg.exe on Windows. So if we get the quirks with Rust worked out, shipping a Rust-based hg.exe should hopefully not be too contentious. Now onto the implementation. We're using python27-sys and the cpython crates for talking to the CPython API. We currently don't use too much functionality of the cpython crate and could have probably cut it out. However, it does provide a reasonable abstraction over unsafe {} CPython function calls. While we still have our fair share of those, at least we're not dealing with too much refcounting, error checking, etc. So I think the use of the cpython crate is justified. Plus, there is not-yet-implemented functionality that could benefit from cpython. I see our use of this crate only increasing. The cpython and python27-sys crates are not without their issues. The cpython crate didn't seem to account for the embedding use case in its design. Instead, it seems to assume that you are building a Python extension. It is making some questionable decisions around certain CPython APIs. For example, it insists that PyEval_ThreadsInitialized() is called and that the Python code likely isn't the main thread in the underlying application. It is also missing some functionality that is important for embedded use cases (such as exporting the path to the Python interpreter from its build script). After spending several hours trying to wrangle python27-sys and cpython, I gave up and forked the project on GitHub. Our Cargo.toml tracks this fork. I'm optimistic that the upstream project will accept our contributions and we can eventually unfork. There is a non-trivial amount of code in our custom Cargo build script. Our build.rs (which is called as part of building the hgcli crate): * Validates that the Python interpreter that was detected by the python27-sys crate provides a shared library (we only support shared library linking at this time - although this restriction could be loosened). * Validates that the Python is built with UCS-4 support. This ensures maximum Unicode compatibility. * Exports variables to the crate build allowing the built crate to e.g. find the path to the Python interpreter. The produced rhg should be considered alpha quality. There are several known deficiencies. Many of these are documented with inline TODOs. Probably the biggest limitation of rhg is that it assumes it is running from the ./rust/target/<target> directory of a source distribution. So, rhg is currently not very practical for real-world use. But, if you can `cargo build` it, running the binary *should* yield a working Mercurial CLI. In order to support using rhg with the test harness, we needed to hack up run-tests.py so the path to Mercurial's Python files is set properly. The change is extremely hacky and is only intended to be a stop-gap until the test harness gains first-class support for installing rhg. This will likely occur after we support running rhg outside the source directory. Despite its officially alpha quality, rhg copes extremely well with the test harness (at least on Linux). Using `run-tests.py --with-hg ../rust/target/debug/hg`, I only encounter the following failures: * test-run-tests.t -- Warnings emitted about using an unexpected Mercurial library. This is due to the hacky nature of setting the Python directory when run-tests.py detected rhg. * test-devel-warnings.t -- Expected stack trace missing frame for `hg` (This is expected since we no longer have an `hg` script!) * test-convert.t -- Test running `$PYTHON "$BINDIR"/hg`, which obviously assumes `hg` is a Python script. * test-merge-tools.t -- Same assumption about `hg` being executable with Python. * test-http-bad-server.t -- Seeing exit code 255 instead of 1 around line 358. * test-blackbox.t -- Exit code 255 instead of 1. * test-basic.t -- Exit code 255 instead of 1. It certainly looks like we have a bug around exit code handling. I don't think it is severe enough to hold up review and landing of this initial implementation. Perfect is the enemy of good. Differential Revision: https://phab.mercurial-scm.org/D1581
author Gregory Szorc <gregory.szorc@gmail.com>
date Wed, 10 Jan 2018 08:53:22 -0800
parents 8b90367c4cf3
children 2372284d9457
line wrap: on
line source

from __future__ import print_function, absolute_import

"""Fuzz testing for operations against a Mercurial repository

This uses Hypothesis's stateful testing to generate random repository
operations and test Mercurial using them, both to see if there are any
unexpected errors and to compare different versions of it."""

import os
import subprocess
import sys

# Only run if slow tests are allowed
if subprocess.call(['python', '%s/hghave' % os.environ['TESTDIR'],
                    'slow']):
    sys.exit(80)

# These tests require Hypothesis and pytz to be installed.
# Running 'pip install hypothesis pytz' will achieve that.
# Note: This won't work if you're running Python < 2.7.
try:
    from hypothesis.extra.datetime import datetimes
except ImportError:
    sys.stderr.write("skipped: hypothesis or pytz not installed" + os.linesep)
    sys.exit(80)

# If you are running an old version of pip you may find that the enum34
# backport is not installed automatically. If so 'pip install enum34' will
# fix this problem.
try:
    import enum
    assert enum  # Silence pyflakes
except ImportError:
    sys.stderr.write("skipped: enum34 not installed" + os.linesep)
    sys.exit(80)

import binascii
from contextlib import contextmanager
import errno
import pipes
import shutil
import silenttestrunner
import subprocess

from hypothesis.errors import HypothesisException
from hypothesis.stateful import (
    rule, RuleBasedStateMachine, Bundle, precondition)
from hypothesis import settings, note, strategies as st
from hypothesis.configuration import set_hypothesis_home_dir
from hypothesis.database import ExampleDatabase

testdir = os.path.abspath(os.environ["TESTDIR"])

# We store Hypothesis examples here rather in the temporary test directory
# so that when rerunning a failing test this always results in refinding the
# previous failure. This directory is in .hgignore and should not be checked in
# but is useful to have for development.
set_hypothesis_home_dir(os.path.join(testdir, ".hypothesis"))

runtests = os.path.join(os.environ["RUNTESTDIR"], "run-tests.py")
testtmp = os.environ["TESTTMP"]
assert os.path.isdir(testtmp)

generatedtests = os.path.join(testdir, "hypothesis-generated")

try:
    os.makedirs(generatedtests)
except OSError:
    pass

# We write out generated .t files to a file in order to ease debugging and to
# give a starting point for turning failures Hypothesis finds into normal
# tests. In order to ensure that multiple copies of this test can be run in
# parallel we use atomic file create to ensure that we always get a unique
# name.
file_index = 0
while True:
    file_index += 1
    savefile = os.path.join(generatedtests, "test-generated-%d.t" % (
        file_index,
    ))
    try:
        os.close(os.open(savefile, os.O_CREAT | os.O_EXCL | os.O_WRONLY))
        break
    except OSError as e:
        if e.errno != errno.EEXIST:
            raise
assert os.path.exists(savefile)

hgrc = os.path.join(".hg", "hgrc")

filecharacters = (
    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    "[]^_`;=@{}~ !#$%&'()+,-"
)

files = st.text(filecharacters, min_size=1).map(lambda x: x.strip()).filter(
    bool).map(lambda s: s.encode('ascii'))

safetext = st.text(st.characters(
    min_codepoint=1, max_codepoint=127,
    blacklist_categories=('Cc', 'Cs')), min_size=1).map(
    lambda s: s.encode('utf-8')
)

extensions = st.sampled_from(('shelve', 'mq', 'blackbox',))

@contextmanager
def acceptableerrors(*args):
    """Sometimes we know an operation we're about to perform might fail, and
    we're OK with some of the failures. In those cases this may be used as a
    context manager and will swallow expected failures, as identified by
    substrings of the error message Mercurial emits."""
    try:
        yield
    except subprocess.CalledProcessError as e:
        if not any(a in e.output for a in args):
            note(e.output)
            raise

reponames = st.text("abcdefghijklmnopqrstuvwxyz01234556789", min_size=1).map(
    lambda s: s.encode('ascii')
)

class verifyingstatemachine(RuleBasedStateMachine):
    """This defines the set of acceptable operations on a Mercurial repository
    using Hypothesis's RuleBasedStateMachine.

    The general concept is that we manage multiple repositories inside a
    repos/ directory in our temporary test location. Some of these are freshly
    inited, some are clones of the others. Our current working directory is
    always inside one of these repositories while the tests are running.

    Hypothesis then performs a series of operations against these repositories,
    including hg commands, generating contents and editing the .hgrc file.
    If these operations fail in unexpected ways or behave differently in
    different configurations of Mercurial, the test will fail and a minimized
    .t test file will be written to the hypothesis-generated directory to
    exhibit that failure.

    Operations are defined as methods with @rule() decorators. See the
    Hypothesis documentation at
    http://hypothesis.readthedocs.org/en/release/stateful.html for more
    details."""

    # A bundle is a reusable collection of previously generated data which may
    # be provided as arguments to future operations.
    repos = Bundle('repos')
    paths = Bundle('paths')
    contents = Bundle('contents')
    branches = Bundle('branches')
    committimes = Bundle('committimes')

    def __init__(self):
        super(verifyingstatemachine, self).__init__()
        self.repodir = os.path.join(testtmp, "repos")
        if os.path.exists(self.repodir):
            shutil.rmtree(self.repodir)
        os.chdir(testtmp)
        self.log = []
        self.failed = False
        self.configperrepo = {}
        self.all_extensions = set()
        self.non_skippable_extensions = set()

        self.mkdirp("repos")
        self.cd("repos")
        self.mkdirp("repo1")
        self.cd("repo1")
        self.hg("init")

    def teardown(self):
        """On teardown we clean up after ourselves as usual, but we also
        do some additional testing: We generate a .t file based on our test
        run using run-test.py -i to get the correct output.

        We then test it in a number of other configurations, verifying that
        each passes the same test."""
        super(verifyingstatemachine, self).teardown()
        try:
            shutil.rmtree(self.repodir)
        except OSError:
            pass
        ttest = os.linesep.join("  " + l for l in self.log)
        os.chdir(testtmp)
        path = os.path.join(testtmp, "test-generated.t")
        with open(path, 'w') as o:
            o.write(ttest + os.linesep)
        with open(os.devnull, "w") as devnull:
            rewriter = subprocess.Popen(
                [runtests, "--local", "-i", path], stdin=subprocess.PIPE,
                stdout=devnull, stderr=devnull,
            )
            rewriter.communicate("yes")
            with open(path, 'r') as i:
                ttest = i.read()

        e = None
        if not self.failed:
            try:
                output = subprocess.check_output([
                    runtests, path, "--local", "--pure"
                ], stderr=subprocess.STDOUT)
                assert "Ran 1 test" in output, output
                for ext in (
                    self.all_extensions - self.non_skippable_extensions
                ):
                    tf = os.path.join(testtmp, "test-generated-no-%s.t" % (
                        ext,
                    ))
                    with open(tf, 'w') as o:
                        for l in ttest.splitlines():
                            if l.startswith("  $ hg"):
                                l = l.replace(
                                    "--config %s=" % (
                                        extensionconfigkey(ext),), "")
                            o.write(l + os.linesep)
                    with open(tf, 'r') as r:
                        t = r.read()
                        assert ext not in t, t
                    output = subprocess.check_output([
                        runtests, tf, "--local",
                    ], stderr=subprocess.STDOUT)
                    assert "Ran 1 test" in output, output
            except subprocess.CalledProcessError as e:
                note(e.output)
        if self.failed or e is not None:
            with open(savefile, "wb") as o:
                o.write(ttest)
        if e is not None:
            raise e

    def execute_step(self, step):
        try:
            return super(verifyingstatemachine, self).execute_step(step)
        except (HypothesisException, KeyboardInterrupt):
            raise
        except Exception:
            self.failed = True
            raise

    # Section: Basic commands.
    def mkdirp(self, path):
        if os.path.exists(path):
            return
        self.log.append(
            "$ mkdir -p -- %s" % (pipes.quote(os.path.relpath(path)),))
        os.makedirs(path)

    def cd(self, path):
        path = os.path.relpath(path)
        if path == ".":
            return
        os.chdir(path)
        self.log.append("$ cd -- %s" % (pipes.quote(path),))

    def hg(self, *args):
        extra_flags = []
        for key, value in self.config.items():
            extra_flags.append("--config")
            extra_flags.append("%s=%s" % (key, value))
        self.command("hg", *(tuple(extra_flags) + args))

    def command(self, *args):
        self.log.append("$ " + ' '.join(map(pipes.quote, args)))
        subprocess.check_output(args, stderr=subprocess.STDOUT)

    # Section: Set up basic data
    # This section has no side effects but generates data that we will want
    # to use later.
    @rule(
        target=paths,
        source=st.lists(files, min_size=1).map(lambda l: os.path.join(*l)))
    def genpath(self, source):
        return source

    @rule(
        target=committimes,
        when=datetimes(min_year=1970, max_year=2038) | st.none())
    def gentime(self, when):
        return when

    @rule(
        target=contents,
        content=st.one_of(
            st.binary(),
            st.text().map(lambda x: x.encode('utf-8'))
        ))
    def gencontent(self, content):
        return content

    @rule(
        target=branches,
        name=safetext,
    )
    def genbranch(self, name):
        return name

    @rule(target=paths, source=paths)
    def lowerpath(self, source):
        return source.lower()

    @rule(target=paths, source=paths)
    def upperpath(self, source):
        return source.upper()

    # Section: Basic path operations
    @rule(path=paths, content=contents)
    def writecontent(self, path, content):
        self.unadded_changes = True
        if os.path.isdir(path):
            return
        parent = os.path.dirname(path)
        if parent:
            try:
                self.mkdirp(parent)
            except OSError:
                # It may be the case that there is a regular file that has
                # previously been created that has the same name as an ancestor
                # of the current path. This will cause mkdirp to fail with this
                # error. We just turn this into a no-op in that case.
                return
        with open(path, 'wb') as o:
            o.write(content)
        self.log.append((
            "$ python -c 'import binascii; "
            "print(binascii.unhexlify(\"%s\"))' > %s") % (
                binascii.hexlify(content),
                pipes.quote(path),
            ))

    @rule(path=paths)
    def addpath(self, path):
        if os.path.exists(path):
            self.hg("add", "--", path)

    @rule(path=paths)
    def forgetpath(self, path):
        if os.path.exists(path):
            with acceptableerrors(
                "file is already untracked",
            ):
                self.hg("forget", "--", path)

    @rule(s=st.none() | st.integers(0, 100))
    def addremove(self, s):
        args = ["addremove"]
        if s is not None:
            args.extend(["-s", str(s)])
        self.hg(*args)

    @rule(path=paths)
    def removepath(self, path):
        if os.path.exists(path):
            with acceptableerrors(
                'file is untracked',
                'file has been marked for add',
                'file is modified',
            ):
                self.hg("remove", "--", path)

    @rule(
        message=safetext,
        amend=st.booleans(),
        when=committimes,
        addremove=st.booleans(),
        secret=st.booleans(),
        close_branch=st.booleans(),
    )
    def maybecommit(
        self, message, amend, when, addremove, secret, close_branch
    ):
        command = ["commit"]
        errors = ["nothing changed"]
        if amend:
            errors.append("cannot amend public changesets")
            command.append("--amend")
        command.append("-m" + pipes.quote(message))
        if secret:
            command.append("--secret")
        if close_branch:
            command.append("--close-branch")
            errors.append("can only close branch heads")
        if addremove:
            command.append("--addremove")
        if when is not None:
            if when.year == 1970:
                errors.append('negative date value')
            if when.year == 2038:
                errors.append('exceeds 32 bits')
            command.append("--date=%s" % (
                when.strftime('%Y-%m-%d %H:%M:%S %z'),))

        with acceptableerrors(*errors):
            self.hg(*command)

    # Section: Repository management
    @property
    def currentrepo(self):
        return os.path.basename(os.getcwd())

    @property
    def config(self):
        return self.configperrepo.setdefault(self.currentrepo, {})

    @rule(
        target=repos,
        source=repos,
        name=reponames,
    )
    def clone(self, source, name):
        if not os.path.exists(os.path.join("..", name)):
            self.cd("..")
            self.hg("clone", source, name)
            self.cd(name)
        return name

    @rule(
        target=repos,
        name=reponames,
    )
    def fresh(self, name):
        if not os.path.exists(os.path.join("..", name)):
            self.cd("..")
            self.mkdirp(name)
            self.cd(name)
            self.hg("init")
        return name

    @rule(name=repos)
    def switch(self, name):
        self.cd(os.path.join("..", name))
        assert self.currentrepo == name
        assert os.path.exists(".hg")

    @rule(target=repos)
    def origin(self):
        return "repo1"

    @rule()
    def pull(self, repo=repos):
        with acceptableerrors(
            "repository default not found",
            "repository is unrelated",
        ):
            self.hg("pull")

    @rule(newbranch=st.booleans())
    def push(self, newbranch):
        with acceptableerrors(
            "default repository not configured",
            "no changes found",
        ):
            if newbranch:
                self.hg("push", "--new-branch")
            else:
                with acceptableerrors(
                    "creates new branches"
                ):
                    self.hg("push")

    # Section: Simple side effect free "check" operations
    @rule()
    def log(self):
        self.hg("log")

    @rule()
    def verify(self):
        self.hg("verify")

    @rule()
    def diff(self):
        self.hg("diff", "--nodates")

    @rule()
    def status(self):
        self.hg("status")

    @rule()
    def export(self):
        self.hg("export")

    # Section: Branch management
    @rule()
    def checkbranch(self):
        self.hg("branch")

    @rule(branch=branches)
    def switchbranch(self, branch):
        with acceptableerrors(
            'cannot use an integer as a name',
            'cannot be used in a name',
            'a branch of the same name already exists',
            'is reserved',
        ):
            self.hg("branch", "--", branch)

    @rule(branch=branches, clean=st.booleans())
    def update(self, branch, clean):
        with acceptableerrors(
            'unknown revision',
            'parse error',
        ):
            if clean:
                self.hg("update", "-C", "--", branch)
            else:
                self.hg("update", "--", branch)

    # Section: Extension management
    def hasextension(self, extension):
        return extensionconfigkey(extension) in self.config

    def commandused(self, extension):
        assert extension in self.all_extensions
        self.non_skippable_extensions.add(extension)

    @rule(extension=extensions)
    def addextension(self, extension):
        self.all_extensions.add(extension)
        self.config[extensionconfigkey(extension)] = ""

    @rule(extension=extensions)
    def removeextension(self, extension):
        self.config.pop(extensionconfigkey(extension), None)

    # Section: Commands from the shelve extension
    @rule()
    @precondition(lambda self: self.hasextension("shelve"))
    def shelve(self):
        self.commandused("shelve")
        with acceptableerrors("nothing changed"):
            self.hg("shelve")

    @rule()
    @precondition(lambda self: self.hasextension("shelve"))
    def unshelve(self):
        self.commandused("shelve")
        with acceptableerrors("no shelved changes to apply"):
            self.hg("unshelve")

class writeonlydatabase(ExampleDatabase):
    def __init__(self, underlying):
        super(ExampleDatabase, self).__init__()
        self.underlying = underlying

    def fetch(self, key):
        return ()

    def save(self, key, value):
        self.underlying.save(key, value)

    def delete(self, key, value):
        self.underlying.delete(key, value)

    def close(self):
        self.underlying.close()

def extensionconfigkey(extension):
    return "extensions." + extension

settings.register_profile(
    'default',  settings(
        timeout=300,
        stateful_step_count=50,
        max_examples=10,
    )
)

settings.register_profile(
    'fast',  settings(
        timeout=10,
        stateful_step_count=20,
        max_examples=5,
        min_satisfying_examples=1,
        max_shrinks=0,
    )
)

settings.register_profile(
    'continuous', settings(
        timeout=-1,
        stateful_step_count=1000,
        max_examples=10 ** 8,
        max_iterations=10 ** 8,
        database=writeonlydatabase(settings.default.database)
    )
)

settings.load_profile(os.getenv('HYPOTHESIS_PROFILE', 'default'))

verifyingtest = verifyingstatemachine.TestCase

verifyingtest.settings = settings.default

if __name__ == '__main__':
    try:
        silenttestrunner.main(__name__)
    finally:
        # So as to prevent proliferation of useless test files, if we never
        # actually wrote a failing test we clean up after ourselves and delete
        # the file for doing so that we owned.
        if os.path.exists(savefile) and os.path.getsize(savefile) == 0:
            os.unlink(savefile)