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# Copyright (c) 2009, Google Inc. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
# * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# Class for unittest support. Used for capturing stderr/stdout.
import logging
import sys
import unittest
from StringIO import StringIO
class OutputCapture(object):
# By default we capture the output to a stream. Other modules may override
# this function in order to do things like pass through the output. See
# webkitpy.test.main for an example.
@staticmethod
def stream_wrapper(stream):
return StringIO()
def __init__(self, log_level=logging.INFO):
self.saved_outputs = dict()
self._log_level = log_level
def set_log_level(self, log_level):
self._log_level = log_level
if hasattr(self, '_logs_handler'):
self._logs_handler.setLevel(self._log_level)
def _capture_output_with_name(self, output_name):
stream = getattr(sys, output_name)
captured_output = self.stream_wrapper(stream)
self.saved_outputs[output_name] = stream
setattr(sys, output_name, captured_output)
return captured_output
def _restore_output_with_name(self, output_name):
captured_output = getattr(sys, output_name).getvalue()
setattr(sys, output_name, self.saved_outputs[output_name])
del self.saved_outputs[output_name]
return captured_output
def capture_output(self):
self._logs = StringIO()
self._logs_handler = logging.StreamHandler(self._logs)
self._logs_handler.setLevel(self._log_level)
self._logger = logging.getLogger()
self._orig_log_level = self._logger.level
self._logger.addHandler(self._logs_handler)
self._logger.setLevel(min(self._log_level, self._orig_log_level))
return (self._capture_output_with_name("stdout"), self._capture_output_with_name("stderr"))
def restore_output(self):
self._logger.removeHandler(self._logs_handler)
self._logger.setLevel(self._orig_log_level)
self._logs_handler.flush()
self._logs.flush()
logs_string = self._logs.getvalue()
delattr(self, '_logs_handler')
delattr(self, '_logs')
return (self._restore_output_with_name("stdout"), self._restore_output_with_name("stderr"), logs_string)
def assert_outputs(self, testcase, function, args=[], kwargs={}, expected_stdout="", expected_stderr="", expected_exception=None, expected_logs=None):
self.capture_output()
try:
if expected_exception:
return_value = testcase.assertRaises(expected_exception, function, *args, **kwargs)
else:
return_value = function(*args, **kwargs)
finally:
(stdout_string, stderr_string, logs_string) = self.restore_output()
if hasattr(testcase, 'assertMultiLineEqual'):
testassert = testcase.assertMultiLineEqual
else:
testassert = testcase.assertEqual
testassert(stdout_string, expected_stdout)
testassert(stderr_string, expected_stderr)
if expected_logs is not None:
testassert(logs_string, expected_logs)
# This is a little strange, but I don't know where else to return this information.
return return_value
class OutputCaptureScope(object):
def __init__(self, output_capture=OutputCapture()):
self._output_capture = output_capture
self.captured_output = (None, None, None)
def __enter__(self):
self._output_capture.capture_output()
def __exit__(self, exc_type, exc_value, traceback):
self.captured_output = self._output_capture.restore_output()
class OutputCaptureTestCaseBase(unittest.TestCase):
maxDiff = None
def setUp(self):
unittest.TestCase.setUp(self)
self.output_capture = OutputCapture()
(self.__captured_stdout, self.__captured_stderr) = self.output_capture.capture_output()
def tearDown(self):
del self.__captured_stdout
del self.__captured_stderr
self.output_capture.restore_output()
unittest.TestCase.tearDown(self)
def assertStdout(self, expected_stdout):
self.assertEqual(expected_stdout, self.__captured_stdout.getvalue())
def assertStderr(self, expected_stderr):
self.assertEqual(expected_stderr, self.__captured_stderr.getvalue())