# Copyright 2010 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS-IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Setuptools extension for running Google-style Python tests.

Google-style Python tests differ from normal Python tests in that each test
module is intended to be executed as an independent script. In particular, the
test fixture code in basetest.main() that executes module-wide setUp() and
tearDown() depends on __main__ being the module under test. This conflicts with
the usual setuptools test style, which uses a single TestSuite to run all of a
package's tests.

This package provides a new setuptools command, google_test, that runs all of
the google-style tests found in a specified directory.

NOTE: This works by overriding sys.modules['__main__'] with the module under
test, but still runs tests in the same process. Thus it will *not* work if your
tests depend on any of the following:
  - Per-process (as opposed to per-module) initialization.
  - Any entry point that is not basetest.main().

To use the google_test command in your project, do something like the following:

In setup.py:
  setup(
      name = "mypackage",
      ...
      setup_requires = ["google-apputils>=0.2"],
      google_test_dir = "tests",
      )

Run:
  $ python setup.py google_test
"""

from distutils import errors
import imp
import os
import re
import shlex
import sys
import traceback

from setuptools.command import test


def ValidateGoogleTestDir(unused_dist, unused_attr, value):
  """Validate that the test directory is a directory."""
  if not os.path.isdir(value):
    raise errors.DistutilsSetupError('%s is not a directory' % value)


class GoogleTest(test.test):
  """Command to run Google-style tests after in-place build."""

  description = 'run Google-style tests after in-place build'

  _DEFAULT_PATTERN = r'_(?:unit|reg)?test\.py$'

  user_options = [
      ('test-dir=', 'd', 'Look for test modules in specified directory.'),
      ('test-module-pattern=', 'p',
       ('Pattern for matching test modules. Defaults to %r. '
        'Only source files (*.py) will be considered, even if more files match '
        'this pattern.' % _DEFAULT_PATTERN)),
      ('test-args=', 'a',
       ('Arguments to pass to basetest.main(). May only make sense if '
        'test_module_pattern matches exactly one test.')),
      ]

  def initialize_options(self):
    self.test_dir = None
    self.test_module_pattern = self._DEFAULT_PATTERN
    self.test_args = ''

    # Set to a dummy value, since we don't call the superclass methods for
    # options parsing.
    self.test_suite = True

  def finalize_options(self):
    if self.test_dir is None:
      if self.distribution.google_test_dir:
        self.test_dir = self.distribution.google_test_dir
      else:
        raise errors.DistutilsOptionError('No test directory specified')

    self.test_module_pattern = re.compile(self.test_module_pattern)
    self.test_args = shlex.split(self.test_args)

  def _RunTestModule(self, module_path):
    """Run a module as a test module given its path.

    Args:
      module_path: The path to the module to test; must end in '.py'.

    Returns:
      True if the tests in this module pass, False if not or if an error occurs.
    """

    path, filename = os.path.split(module_path)

    old_argv = sys.argv[:]
    old_path = sys.path[:]
    old_modules = sys.modules.copy()

    # Make relative imports in test modules work with our mangled sys.path.
    sys.path.insert(0, path)

    module_name = filename.replace('.py', '')
    import_tuple = imp.find_module(module_name, [path])
    module = imp.load_module(module_name, *import_tuple)

    sys.modules['__main__'] = module
    sys.argv = [module.__file__] + self.test_args

    # Late import since this must be run with the project's sys.path.
    from . import basetest
    try:
      try:
        sys.stderr.write('Testing %s\n' % module_name)
        basetest.main()

        # basetest.main() should always call sys.exit, so this is very bad.
        return False
      except SystemExit as e:
        returncode, = e.args
        return not returncode
      except:
        traceback.print_exc()
        return False
    finally:
      sys.argv[:] = old_argv
      sys.path[:] = old_path
      sys.modules.clear()
      sys.modules.update(old_modules)

  def run_tests(self):
    ok = True
    for path, _, filenames in os.walk(self.test_dir):
      for filename in filenames:
        if not filename.endswith('.py'):
          continue
        file_path = os.path.join(path, filename)
        if self.test_module_pattern.search(file_path):
          ok &= self._RunTestModule(file_path)

    sys.exit(int(not ok))