annotate tests/hghave @ 40009:842ffcf1d42f

storageutil: extract most of emitrevisions() to standalone function

As part of implementing a storage backend, I found myself copying
most of revlog.emitrevisions(). This code is highly nuanced and it
bothered me greatly to be copying such low-level code.

This commit extracts the bulk of revlog.emitrevisions() into a
new standalone function. In order to make the function generally
usable, all "self" function calls that aren't exposed on the
ifilestorage interface are passed in via callable arguments.

No meaningful behavior should have changed as part of the port.

Upcoming commits will tweak behavior to make the code more
generically usable.

Differential Revision: https://phab.mercurial-scm.org/D4803

#!/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 absolute_import, print_function

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)