tests/hghave

Add hghave utility and run-tests.py support.

hghave detects system features like symlinks availability at run-time. Tests can be skipped by starting them with:

"$TESTDIR/hghave" symlink || exit 80

The 80 exit status triggers hghave output handling by run-tests.py. Also, tests output can be locally patched on the fly to match reference output.

#!/usr/bin/env python
"""Test the running system for features availability. Exit with zero
if all features are there, non-zero otherwise.
"""
import optparse
import os
import sys

def has_symlink():
    return hasattr(os, "symlink")

checks = {
    "symlink": (has_symlink, "symbolic links"),
}

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

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

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

    failures = 0

    def error(msg):
        global failures
        if not quiet:
            sys.stderr.write(msg + '\n')
        failures += 1
    
    for feature in args:
        if feature not in checks:
            error('hghave: unknown feature: ' + feature)
            continue
        
        check, desc = checks[feature]       
        if not check():
            error('hghave: missing feature: ' + desc)

    if failures != 0:
        sys.exit(1)