view tests/hghave @ 28450:155e3308289c

hgext: officially turn 'hgext' into a namespace package

Actually since Python 2.3, there is some way to turn top level package into
"namespace package" so that multiple subpackage installed in different part of
the path can still be imported transparently. This feature was previously
thought (at least by myself) to be only provided by some setuptool black magic.

Turning hgext into such namespace package allows third extensions to install
themselves inside the "hgext" namespace package to avoid polluting the global
python module namespace. They will now be able to do so without making it a pain
to use a Mercurial "installed" in a different way/location than these
extensions.

The only constrains is that the extension ship a 'hgext/__init__.py' containing
the same call to 'pkgutil.extend_path' and nothing else. This seems realistic.

The main question that remains is: should we introduce a dedicated namespace for
third party extension (hgext3rd?) to make a clearer distinction between what is
officially supported and what is not? If so, this will be introduced in a follow
up patch.

#!/usr/bin/env python
"""Test the running system for features availability. Exit with zero
if all features are there, non-zero otherwise. If a feature name is
prefixed with "no-", the absence of feature is tested.
"""

from __future__ import print_function

import optparse
import os, sys
import hghave

checks = hghave.checks

def list_features():
    for name, feature in sorted(checks.iteritems()):
        desc = feature[1]
        print(name + ':', desc)

def test_features():
    failed = 0
    for name, feature in checks.iteritems():
        check, _ = feature
        try:
            check()
        except Exception as e:
            print("feature %s failed:  %s" % (name, e))
            failed += 1
    return failed

parser = optparse.OptionParser("%prog [options] [features]")
parser.add_option("--test-features", action="store_true",
                  help="test available features")
parser.add_option("--list-features", action="store_true",
                  help="list available features")

def _loadaddon():
    if 'TESTDIR' in os.environ:
        # loading from '.' isn't needed, because `hghave` should be
        # running at TESTTMP in this case
        path = os.environ['TESTDIR']
    else:
        path = '.'

    if not os.path.exists(os.path.join(path, 'hghaveaddon.py')):
        return

    sys.path.insert(0, path)
    try:
        import hghaveaddon
    except BaseException as inst:
        sys.stderr.write('failed to import hghaveaddon.py from %r: %s\n'
                         % (path, inst))
        sys.exit(2)
    sys.path.pop(0)

if __name__ == '__main__':
    options, args = parser.parse_args()
    _loadaddon()
    if options.list_features:
        list_features()
        sys.exit(0)

    if options.test_features:
        sys.exit(test_features())

    hghave.require(args)