tests/sitecustomize.py

ui: add a "config_default" method

This allow code to access the expected value for a config. This is useful in the
context of dynamic default value, and short term it will be useful to write
dynamically "correct" code.

Differential Revision: https://phab.mercurial-scm.org/D9759

from __future__ import absolute_import
import os

if os.environ.get('COVERAGE_PROCESS_START'):
    try:
        import coverage
        import uuid

        covpath = os.path.join(
            os.environ['COVERAGE_DIR'], 'cov.%s' % uuid.uuid1()
        )
        cov = coverage.coverage(data_file=covpath, auto_data=True)
        cov._warn_no_data = False
        cov._warn_unimported_source = False
        cov.start()
    except ImportError:
        pass