tests/silenttestrunner.py

patch: enable diff.tab markup for the color extension

The following patch splits up changed lines along tabs (using
re.findall), and gives them a "diff.tab" label. This can be used by
the color extension for colorising tabs, like it does right now with
trailing whitespace.

I also provide corresponding tests.

import unittest, sys

def main(modulename):
    '''run the tests found in module, printing nothing when all tests pass'''
    module = sys.modules[modulename]
    suite = unittest.defaultTestLoader.loadTestsFromModule(module)
    results = unittest.TestResult()
    suite.run(results)
    if results.errors or results.failures:
        for tc, exc in results.errors:
            print 'ERROR:', tc
            print
            sys.stdout.write(exc)
        for tc, exc in results.failures:
            print 'FAIL:', tc
            print
            sys.stdout.write(exc)
        sys.exit(1)