Mercurial > hg-stable
changeset 28255:f75f7d39cca3
testing: generate tests operations using Hypothesis
The idea of this patch is to expand the use of Hypothesis
within Mercurial to use its concept of "stateful testing".
The result is a test which runs a sequence of operations
against a Mercurial repository. Each operation is given a
set of allowed ways it can fail. Any other non-zero exit
code is a test failure.
At the end, the whole sequence is then reverified by
generating a .t test and testing it again in pure
mode (this is also useful for catching non-determinism
bugs).
This has proven reasonably effective at finding bugs,
and has identified two problems in the shelve extension
already (issue5113 and issue5112).
author | David R. MacIver <david@drmaciver.com> |
---|---|
date | Wed, 24 Feb 2016 13:05:45 +0000 |
parents | 4591cd6b6794 |
children | 55325bdf6c13 |
files | .hgignore tests/test-verify-repo-operations.py |
diffstat | 2 files changed, 406 insertions(+), 0 deletions(-) [+] |
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--- a/.hgignore Thu Feb 25 16:54:14 2016 +0000 +++ b/.hgignore Wed Feb 24 13:05:45 2016 +0000 @@ -21,6 +21,8 @@ .\#* tests/.coverage* tests/.testtimes* +tests/.hypothesis +tests/hypothesis-generated tests/annotated tests/*.err tests/htmlcov
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/tests/test-verify-repo-operations.py Wed Feb 24 13:05:45 2016 +0000 @@ -0,0 +1,404 @@ +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 sys + +# 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 +from hypothesis import settings, note, strategies as st +from hypothesis.configuration import set_hypothesis_home_dir + +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') +) + +@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 + +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. + paths = Bundle('paths') + contents = Bundle('contents') + committimes = Bundle('committimes') + + def __init__(self): + super(verifyingstatemachine, self).__init__() + self.repodir = os.path.join(testtmp, "repo") + if os.path.exists(self.repodir): + shutil.rmtree(self.repodir) + os.chdir(testtmp) + self.log = [] + self.failed = False + + self.mkdirp("repo") + self.cd("repo") + 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 + except subprocess.CalledProcessError as e: + note(e.output) + finally: + os.unlink(path) + try: + os.unlink(path + ".err") + except OSError: + pass + 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): + self.command("hg", *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=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: 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") + +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.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)