tests/test-config-env.py

narrowspec: move module into core

Having support for parsing the narrow specification in core is
necessary for moving many other parts of narrow to core.

We do still want to harmonize the narrow spec with the sparse
spec. And the format needs to be documented. But this shouldn't
hold up the code moving to core.

Differential Revision: https://phab.mercurial-scm.org/D2201

# Test the config layer generated by environment variables

from __future__ import absolute_import, print_function

import os

from mercurial import (
    encoding,
    rcutil,
    ui as uimod,
    util,
)

testtmp = encoding.environ['TESTTMP']

# prepare hgrc files
def join(name):
    return os.path.join(testtmp, name)

with open(join('sysrc'), 'w') as f:
    f.write('[ui]\neditor=e0\n[pager]\npager=p0\n')

with open(join('userrc'), 'w') as f:
    f.write('[ui]\neditor=e1')

# replace rcpath functions so they point to the files above
def systemrcpath():
    return [join('sysrc')]

def userrcpath():
    return [join('userrc')]

rcutil.systemrcpath = systemrcpath
rcutil.userrcpath = userrcpath
os.path.isdir = lambda x: False # hack: do not load default.d/*.rc

# utility to print configs
def printconfigs(env):
    encoding.environ = env
    rcutil._rccomponents = None # reset cache
    ui = uimod.ui.load()
    for section, name, value in ui.walkconfig():
        source = ui.configsource(section, name)
        print('%s.%s=%s # %s' % (section, name, value, util.pconvert(source)))
    print('')

# environment variable overrides
printconfigs({})
printconfigs({'EDITOR': 'e2', 'PAGER': 'p2'})