hghave: add docstring for check

tests/hghave.py

@@ -1,464 +1,465 b''
 from __future__ import absolute_import
 
 import errno
 import os
 import re
 import socket
 import stat
 import subprocess
 import sys
 import tempfile
 
 tempprefix = 'hg-hghave-'
 
 checks = {
     "true": (lambda: True, "yak shaving"),
     "false": (lambda: False, "nail clipper"),
 }
 
 def check(name, desc):
+    """Registers a check function for a feature."""
     def decorator(func):
         checks[name] = (func, desc)
         return func
     return decorator
 
 def checkfeatures(features):
     result = {
         'error': [],
         'missing': [],
         'skipped': [],
     }
 
     for feature in features:
         negate = feature.startswith('no-')
         if negate:
             feature = feature[3:]
 
         if feature not in checks:
             result['missing'].append(feature)
             continue
 
         check, desc = checks[feature]
         try:
             available = check()
         except Exception:
             result['error'].append('hghave check failed: %s' % feature)
             continue
 
         if not negate and not available:
             result['skipped'].append('missing feature: %s' % desc)
         elif negate and available:
             result['skipped'].append('system supports %s' % desc)
 
     return result
 
 def require(features):
     """Require that features are available, exiting if not."""
     result = checkfeatures(features)
 
     for missing in result['missing']:
         sys.stderr.write('skipped: unknown feature: %s\n' % missing)
     for msg in result['skipped']:
         sys.stderr.write('skipped: %s\n' % msg)
     for msg in result['error']:
         sys.stderr.write('%s\n' % msg)
 
     if result['missing']:
         sys.exit(2)
 
     if result['skipped'] or result['error']:
         sys.exit(1)
 
 def matchoutput(cmd, regexp, ignorestatus=False):
     """Return the match object if cmd executes successfully and its output
     is matched by the supplied regular expression.
     """
     r = re.compile(regexp)
     try:
         p = subprocess.Popen(
             cmd, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
     except OSError as e:
         if e.errno != errno.ENOENT:
             raise
         ret = -1
     ret = p.wait()
     s = p.stdout.read()
     return (ignorestatus or not ret) and r.search(s)
 
 @check("baz", "GNU Arch baz client")
 def has_baz():
     return matchoutput('baz --version 2>&1', r'baz Bazaar version')
 
 @check("bzr", "Canonical's Bazaar client")
 def has_bzr():
     try:
         import bzrlib
         return bzrlib.__doc__ is not None
     except ImportError:
         return False
 
 @check("bzr114", "Canonical's Bazaar client >= 1.14")
 def has_bzr114():
     try:
         import bzrlib
         return (bzrlib.__doc__ is not None
                 and bzrlib.version_info[:2] >= (1, 14))
     except ImportError:
         return False
 
 @check("cvs", "cvs client/server")
 def has_cvs():
     re = r'Concurrent Versions System.*?server'
     return matchoutput('cvs --version 2>&1', re) and not has_msys()
 
 @check("cvs112", "cvs client/server 1.12.* (not cvsnt)")
 def has_cvs112():
     re = r'Concurrent Versions System \(CVS\) 1.12.*?server'
     return matchoutput('cvs --version 2>&1', re) and not has_msys()
 
 @check("darcs", "darcs client")
 def has_darcs():
     return matchoutput('darcs --version', r'2\.[2-9]', True)
 
 @check("mtn", "monotone client (>= 1.0)")
 def has_mtn():
     return matchoutput('mtn --version', r'monotone', True) and not matchoutput(
         'mtn --version', r'monotone 0\.', True)
 
 @check("eol-in-paths", "end-of-lines in paths")
 def has_eol_in_paths():
     try:
         fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix, suffix='\n\r')
         os.close(fd)
         os.remove(path)
         return True
     except (IOError, OSError):
         return False
 
 @check("execbit", "executable bit")
 def has_executablebit():
     try:
         EXECFLAGS = stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH
         fh, fn = tempfile.mkstemp(dir='.', prefix=tempprefix)
         try:
             os.close(fh)
             m = os.stat(fn).st_mode & 0o777
             new_file_has_exec = m & EXECFLAGS
             os.chmod(fn, m ^ EXECFLAGS)
             exec_flags_cannot_flip = ((os.stat(fn).st_mode & 0o777) == m)
         finally:
             os.unlink(fn)
     except (IOError, OSError):
         # we don't care, the user probably won't be able to commit anyway
         return False
     return not (new_file_has_exec or exec_flags_cannot_flip)
 
 @check("icasefs", "case insensitive file system")
 def has_icasefs():
     # Stolen from mercurial.util
     fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix)
     os.close(fd)
     try:
         s1 = os.stat(path)
         d, b = os.path.split(path)
         p2 = os.path.join(d, b.upper())
         if path == p2:
             p2 = os.path.join(d, b.lower())
         try:
             s2 = os.stat(p2)
             return s2 == s1
         except OSError:
             return False
     finally:
         os.remove(path)
 
 @check("fifo", "named pipes")
 def has_fifo():
     if getattr(os, "mkfifo", None) is None:
         return False
     name = tempfile.mktemp(dir='.', prefix=tempprefix)
     try:
         os.mkfifo(name)
         os.unlink(name)
         return True
     except OSError:
         return False
 
 @check("killdaemons", 'killdaemons.py support')
 def has_killdaemons():
     return True
 
 @check("cacheable", "cacheable filesystem")
 def has_cacheable_fs():
     from mercurial import util
 
     fd, path = tempfile.mkstemp(dir='.', prefix=tempprefix)
     os.close(fd)
     try:
         return util.cachestat(path).cacheable()
     finally:
         os.remove(path)
 
 @check("lsprof", "python lsprof module")
 def has_lsprof():
     try:
         import _lsprof
         _lsprof.Profiler # silence unused import warning
         return True
     except ImportError:
         return False
 
 @check("gettext", "GNU Gettext (msgfmt)")
 def has_gettext():
     return matchoutput('msgfmt --version', 'GNU gettext-tools')
 
 @check("git", "git command line client")
 def has_git():
     return matchoutput('git --version 2>&1', r'^git version')
 
 @check("docutils", "Docutils text processing library")
 def has_docutils():
     try:
         from docutils.core import publish_cmdline
         publish_cmdline # silence unused import
         return True
     except ImportError:
         return False
 
 def getsvnversion():
     m = matchoutput('svn --version --quiet 2>&1', r'^(\d+)\.(\d+)')
     if not m:
         return (0, 0)
     return (int(m.group(1)), int(m.group(2)))
 
 @check("svn15", "subversion client and admin tools >= 1.5")
 def has_svn15():
     return getsvnversion() >= (1, 5)
 
 @check("svn13", "subversion client and admin tools >= 1.3")
 def has_svn13():
     return getsvnversion() >= (1, 3)
 
 @check("svn", "subversion client and admin tools")
 def has_svn():
     return matchoutput('svn --version 2>&1', r'^svn, version') and \
         matchoutput('svnadmin --version 2>&1', r'^svnadmin, version')
 
 @check("svn-bindings", "subversion python bindings")
 def has_svn_bindings():
     try:
         import svn.core
         version = svn.core.SVN_VER_MAJOR, svn.core.SVN_VER_MINOR
         if version < (1, 4):
             return False
         return True
     except ImportError:
         return False
 
 @check("p4", "Perforce server and client")
 def has_p4():
     return (matchoutput('p4 -V', r'Rev\. P4/') and
             matchoutput('p4d -V', r'Rev\. P4D/'))
 
 @check("symlink", "symbolic links")
 def has_symlink():
     if getattr(os, "symlink", None) is None:
         return False
     name = tempfile.mktemp(dir='.', prefix=tempprefix)
     try:
         os.symlink(".", name)
         os.unlink(name)
         return True
     except (OSError, AttributeError):
         return False
 
 @check("hardlink", "hardlinks")
 def has_hardlink():
     from mercurial import util
     fh, fn = tempfile.mkstemp(dir='.', prefix=tempprefix)
     os.close(fh)
     name = tempfile.mktemp(dir='.', prefix=tempprefix)
     try:
         util.oslink(fn, name)
         os.unlink(name)
         return True
     except OSError:
         return False
     finally:
         os.unlink(fn)
 
 @check("tla", "GNU Arch tla client")
 def has_tla():
     return matchoutput('tla --version 2>&1', r'The GNU Arch Revision')
 
 @check("gpg", "gpg client")
 def has_gpg():
     return matchoutput('gpg --version 2>&1', r'GnuPG')
 
 @check("unix-permissions", "unix-style permissions")
 def has_unix_permissions():
     d = tempfile.mkdtemp(dir='.', prefix=tempprefix)
     try:
         fname = os.path.join(d, 'foo')
         for umask in (0o77, 0o07, 0o22):
             os.umask(umask)
             f = open(fname, 'w')
             f.close()
             mode = os.stat(fname).st_mode
             os.unlink(fname)
             if mode & 0o777 != ~umask & 0o666:
                 return False
         return True
     finally:
         os.rmdir(d)
 
 @check("unix-socket", "AF_UNIX socket family")
 def has_unix_socket():
     return getattr(socket, 'AF_UNIX', None) is not None
 
 @check("root", "root permissions")
 def has_root():
     return getattr(os, 'geteuid', None) and os.geteuid() == 0
 
 @check("pyflakes", "Pyflakes python linter")
 def has_pyflakes():
     return matchoutput("sh -c \"echo 'import re' 2>&1 | pyflakes\"",
                        r"<stdin>:1: 're' imported but unused",
                        True)
 
 @check("pygments", "Pygments source highlighting library")
 def has_pygments():
     try:
         import pygments
         pygments.highlight # silence unused import warning
         return True
     except ImportError:
         return False
 
 @check("outer-repo", "outer repo")
 def has_outer_repo():
     # failing for other reasons than 'no repo' imply that there is a repo
     return not matchoutput('hg root 2>&1',
                            r'abort: no repository found', True)
 
 @check("ssl", "ssl module available")
 def has_ssl():
     try:
         import ssl
         ssl.CERT_NONE
         return True
     except ImportError:
         return False
 
 @check("sslcontext", "python >= 2.7.9 ssl")
 def has_sslcontext():
     try:
         import ssl
         ssl.SSLContext
         return True
     except (ImportError, AttributeError):
         return False
 
 @check("defaultcacerts", "can verify SSL certs by system's CA certs store")
 def has_defaultcacerts():
     from mercurial import sslutil
     return sslutil._defaultcacerts() != '!'
 
 @check("windows", "Windows")
 def has_windows():
     return os.name == 'nt'
 
 @check("system-sh", "system() uses sh")
 def has_system_sh():
     return os.name != 'nt'
 
 @check("serve", "platform and python can manage 'hg serve -d'")
 def has_serve():
     return os.name != 'nt' # gross approximation
 
 @check("test-repo", "running tests from repository")
 def has_test_repo():
     t = os.environ["TESTDIR"]
     return os.path.isdir(os.path.join(t, "..", ".hg"))
 
 @check("tic", "terminfo compiler and curses module")
 def has_tic():
     try:
         import curses
         curses.COLOR_BLUE
         return matchoutput('test -x "`which tic`"', '')
     except ImportError:
         return False
 
 @check("msys", "Windows with MSYS")
 def has_msys():
     return os.getenv('MSYSTEM')
 
 @check("aix", "AIX")
 def has_aix():
     return sys.platform.startswith("aix")
 
 @check("osx", "OS X")
 def has_osx():
     return sys.platform == 'darwin'
 
 @check("docker", "docker support")
 def has_docker():
     pat = r'A self-sufficient runtime for linux containers\.'
     if matchoutput('docker --help', pat):
         if 'linux' not in sys.platform:
             # TODO: in theory we should be able to test docker-based
             # package creation on non-linux using boot2docker, but in
             # practice that requires extra coordination to make sure
             # $TESTTEMP is going to be visible at the same path to the
             # boot2docker VM. If we figure out how to verify that, we
             # can use the following instead of just saying False:
             # return 'DOCKER_HOST' in os.environ
             return False
 
         return True
     return False
 
 @check("debhelper", "debian packaging tools")
 def has_debhelper():
     dpkg = matchoutput('dpkg --version',
                        "Debian `dpkg' package management program")
     dh = matchoutput('dh --help',
                      'dh is a part of debhelper.', ignorestatus=True)
     dh_py2 = matchoutput('dh_python2 --help',
                          'other supported Python versions')
     return dpkg and dh and dh_py2
 
 @check("absimport", "absolute_import in __future__")
 def has_absimport():
     import __future__
     from mercurial import util
     return util.safehasattr(__future__, "absolute_import")
 
 @check("py3k", "running with Python 3.x")
 def has_py3k():
     return 3 == sys.version_info[0]
 
 @check("py3exe", "a Python 3.x interpreter is available")
 def has_python3exe():
     return 'PYTHON3' in os.environ
 
 @check("pure", "running with pure Python code")
 def has_pure():
     return any([
         os.environ.get("HGMODULEPOLICY") == "py",
         os.environ.get("HGTEST_RUN_TESTS_PURE") == "--pure",
     ])
 
 @check("slow", "allow slow tests")
 def has_slow():
     return os.environ.get('HGTEST_SLOW') == 'slow'
 
 @check("hypothesis", "Hypothesis automated test generation")
 def has_hypothesis():
     try:
         import hypothesis
         hypothesis.given
         return True
     except ImportError:
         return False