tests/hghave

hg-cpython: fallback when encountering an unknown matcher

At this point in the process, nothing user-visible has happened, it is still
safe to fallback. This can happen now that we're going to be using
"container matchers" like unionmatcher and intersectionmatcher.

This is easier and less error-prone than recursive checking beforehand since
only the presence of a transformation case will allow the process to continue.

#!/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.
"""


import hghave
import optparse
import os
import sys

checks = hghave.checks


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


def test_features():
    failed = 0
    for name, feature in checks.items():
        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

        assert hghaveaddon  # silence pyflakes
    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)