tests/hghave

revset: use delayregistrar to register predicate in extension easily

Previous patch introduced 'revset.predicate' decorator to register
revset predicate function easily.

But it shouldn't be used in extension directly, because it registers
specified function immediately. Registration itself can't be restored,
even if extension loading fails after that.

Therefore, registration should be delayed until 'uisetup()' or so.

This patch uses 'extpredicate' decorator derived from 'delayregistrar'
to register predicate in extension easily.

This patch also tests whether 'registrar.delayregistrar' avoids
function registration if 'setup()' isn't invoked on it, because
'extpredicate' is the first user of it.

#!/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 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, 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, 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)