tests/silenttestrunner.py

profiling: add statprof support for Chrome trace viewer rendering

We synthesize function call begin/end events from snapshots, and
try (configurably) to eliminate "noisy" stack frames.

Example invocation:

hg --config profiling.output=$HOME/Desktop/clone.json \
   --config profiling.statformat=chrome \
   --profile clone https://www.mercurial-scm.org/repo/hg

from __future__ import absolute_import, print_function
import os
import sys
import unittest

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)

if os.environ.get('SILENT_BE_NOISY'):
    main = unittest.main