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Testing Environment Variable Parsing Implementation in Telegram

This test suite validates Google Test’s environment variable parsing functionality within the Telegram project. It ensures proper handling of configuration settings through environment variables and their corresponding command line flags.

Test Coverage Overview

The test suite provides comprehensive coverage of Google Test’s environment variable handling mechanisms.

Key areas tested include:

Environment variable to flag mapping verification
Default value handling when variables are unset
XML output file configuration
Platform-specific settings for Linux and Windows
Override behavior between different configuration methods

Implementation Analysis

The testing approach utilizes Python’s unittest framework to systematically verify environment variable parsing. The implementation employs helper functions for setting environment variables and executing the test binary, following a consistent pattern of setting variables, running tests, and verifying outputs.

Key patterns include:

Isolated environment variable manipulation
Subprocess execution for testing
Assertion-based verification
Platform-specific test branching

Technical Details

Testing tools and configuration:

Python unittest framework
Custom test utilities (gtest_test_utils)
Environment variable manipulation through os.environ
Platform detection for conditional testing
Subprocess execution for isolated test runs
Custom assertion utilities for precise verification

Best Practices Demonstrated

The test suite exemplifies several testing best practices in environment variable handling.

Notable practices include:

Isolation of test environments
Cleanup of modified environment states
Platform-aware test execution
Comprehensive error messages
Modular test helper functions
Clear test case organization

drklo/telegram

TMessagesProj/jni/boringssl/third_party/googletest/test/googletest-env-var-test.py

            
#!/usr/bin/env python
#
# Copyright 2008, 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.

"""Verifies that Google Test correctly parses environment variables."""

import os
import gtest_test_utils


IS_WINDOWS = os.name == 'nt'
IS_LINUX = os.name == 'posix' and os.uname()[0] == 'Linux'

COMMAND = gtest_test_utils.GetTestExecutablePath('googletest-env-var-test_')

environ = os.environ.copy()


def AssertEq(expected, actual):
  if expected != actual:
    print('Expected: %s' % (expected,))
    print('  Actual: %s' % (actual,))
    raise AssertionError


def SetEnvVar(env_var, value):
  """Sets the env variable to 'value'; unsets it when 'value' is None."""

  if value is not None:
    environ[env_var] = value
  elif env_var in environ:
    del environ[env_var]


def GetFlag(flag):
  """Runs googletest-env-var-test_ and returns its output."""

  args = [COMMAND]
  if flag is not None:
    args += [flag]
  return gtest_test_utils.Subprocess(args, env=environ).output


def TestFlag(flag, test_val, default_val):
  """Verifies that the given flag is affected by the corresponding env var."""

  env_var = 'GTEST_' + flag.upper()
  SetEnvVar(env_var, test_val)
  AssertEq(test_val, GetFlag(flag))
  SetEnvVar(env_var, None)
  AssertEq(default_val, GetFlag(flag))


class GTestEnvVarTest(gtest_test_utils.TestCase):

  def testEnvVarAffectsFlag(self):
    """Tests that environment variable should affect the corresponding flag."""

    TestFlag('break_on_failure', '1', '0')
    TestFlag('color', 'yes', 'auto')
    TestFlag('filter', 'FooTest.Bar', '*')
    SetEnvVar('XML_OUTPUT_FILE', None)  # For 'output' test
    TestFlag('output', 'xml:tmp/foo.xml', '')
    TestFlag('print_time', '0', '1')
    TestFlag('repeat', '999', '1')
    TestFlag('throw_on_failure', '1', '0')
    TestFlag('death_test_style', 'threadsafe', 'fast')
    TestFlag('catch_exceptions', '0', '1')

    if IS_LINUX:
      TestFlag('death_test_use_fork', '1', '0')
      TestFlag('stack_trace_depth', '0', '100')


  def testXmlOutputFile(self):
    """Tests that $XML_OUTPUT_FILE affects the output flag."""

    SetEnvVar('GTEST_OUTPUT', None)
    SetEnvVar('XML_OUTPUT_FILE', 'tmp/bar.xml')
    AssertEq('xml:tmp/bar.xml', GetFlag('output'))

  def testXmlOutputFileOverride(self):
    """Tests that $XML_OUTPUT_FILE is overridden by $GTEST_OUTPUT."""

    SetEnvVar('GTEST_OUTPUT', 'xml:tmp/foo.xml')
    SetEnvVar('XML_OUTPUT_FILE', 'tmp/bar.xml')
    AssertEq('xml:tmp/foo.xml', GetFlag('output'))

if __name__ == '__main__':
  gtest_test_utils.Main()