test/gtest_test_utils.py

#!/usr/bin/env python
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"""Unit test utilities for Google C++ Testing Framework."""

__author__ = 'wan@google.com (Zhanyong Wan)'

import os
import sys
import unittest


# Initially maps a flag to its default value.  After
# _ParseAndStripGTestFlags() is called, maps a flag to its actual
# value.
_flag_map = {'gtest_source_dir': os.path.dirname(sys.argv[0]),
             'gtest_build_dir': os.path.dirname(sys.argv[0])}
_gtest_flags_are_parsed = False


def _ParseAndStripGTestFlags(argv):
  """Parses and strips Google Test flags from argv.  This is idempotent."""

  global _gtest_flags_are_parsed
  if _gtest_flags_are_parsed:
    return

  _gtest_flags_are_parsed = True
  for flag in _flag_map:
    # The environment variable overrides the default value.
    if flag.upper() in os.environ:
      _flag_map[flag] = os.environ[flag.upper()]

    # The command line flag overrides the environment variable.
    i = 1  # Skips the program name.
    while i < len(argv):
      prefix = '--' + flag + '='
      if argv[i].startswith(prefix):
        _flag_map[flag] = argv[i][len(prefix):]
        del argv[i]
        break
      else:
        # We don't increment i in case we just found a --gtest_* flag
        # and removed it from argv.
        i += 1


def GetFlag(flag):
  """Returns the value of the given flag."""

  # In case GetFlag() is called before Main(), we always call
  # _ParseAndStripGTestFlags() here to make sure the --gtest_* flags
  # are parsed.
  _ParseAndStripGTestFlags(sys.argv)

  return _flag_map[flag]


def GetSourceDir():
  """Returns the absolute path of the directory where the .py files are."""

  return os.path.abspath(GetFlag('gtest_source_dir'))


def GetBuildDir():
  """Returns the absolute path of the directory where the test binaries are."""

  return os.path.abspath(GetFlag('gtest_build_dir'))


def GetExitStatus(exit_code):
  """Returns the argument to exit(), or -1 if exit() wasn't called.

  Args:
    exit_code: the result value of os.system(command).
  """

  if os.name == 'nt':
    # On Windows, os.WEXITSTATUS() doesn't work and os.system() returns
    # the argument to exit() directly.
    return exit_code
  else:
    # On Unix, os.WEXITSTATUS() must be used to extract the exit status
    # from the result of os.system().
    if os.WIFEXITED(exit_code):
      return os.WEXITSTATUS(exit_code)
    else:
      return -1


def Main():
  """Runs the unit test."""

  # We must call _ParseAndStripGTestFlags() before calling
  # unittest.main().  Otherwise the latter will be confused by the
  # --gtest_* flags.
  _ParseAndStripGTestFlags(sys.argv)
  unittest.main()