Revert "Save cookies back to jar when fetching clone.bundle"

This reverts commit 4abf8e6ef8.

The curl process for updating the cookie file is not atomic.  When
fetching many bundles in parallel, we can sometimes corrupt the file
causing it to be cleared.  Since users should manage gitcookies on
their own, leave it read-only.

Bug: https://crbug.com/gerrit/12300
Change-Id: Id472c99b197bc4cf8533c649f8881509f38643c1
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/254092
Reviewed-by: David Pursehouse <dpursehouse@collab.net>
Tested-by: Mike Frysinger <vapier@google.com>
(cherry picked from commit dc1d0e0c7f)

.gitignore

@@ -1,3 +1,11 @@
+*.egg-info/
+*.log
 *.pyc
+__pycache__
+/dist
 .repopickle_*
 /repoc
+/.tox
+
+# PyCharm related
+/.idea/

MANIFEST.in

@@ -0,0 +1,6 @@
+graft docs hooks tests
+include *.py
+include LICENSE
+include git_ssh
+include repo
+include run_tests

README.md

@@ -14,6 +14,7 @@ that you can put anywhere in your path.
 * [repo Manifest Format](./docs/manifest-format.md)
 * [repo Hooks](./docs/repo-hooks.md)
 * [Submitting patches](./SUBMITTING_PATCHES.md)
+* Running Repo in [Microsoft Windows](./docs/windows.md)
 
 ## Install
 

SUBMITTING_PATCHES.md

@@ -69,10 +69,38 @@ suppressed in the included `.flake8` file.
 
 ## Running tests
 
-There is a [`./run_tests`](./run_tests) helper script for quickly invoking all
-of our unittests.  The coverage isn't great currently, but it should still be
-run for all commits.
+We use [pytest](https://pytest.org/) and [tox](https://tox.readthedocs.io/) for
+running tests.  You should make sure to install those first.
 
+To run the full suite against all supported Python versions, simply execute:
+```sh
+$ tox -p auto
+```
+
+We have [`./run_tests`](./run_tests) which is a simple wrapper around `pytest`:
+```sh
+# Run the full suite against the default Python version.
+$ ./run_tests
+# List each test as it runs.
+$ ./run_tests -v
+
+# Run a specific unittest module (and all tests in it).
+$ ./run_tests tests/test_git_command.py
+
+# Run a specific testsuite in a specific unittest module.
+$ ./run_tests tests/test_editor.py::EditString
+
+# Run a single test.
+$ ./run_tests tests/test_editor.py::EditString::test_cat_editor
+
+# List all available tests.
+$ ./run_tests --collect-only
+
+# Run a single test using substring match.
+$ ./run_tests -k test_cat_editor
+```
+
+The coverage isn't great currently, but it should still be run for all commits.
 Adding more unittests for changes you make would be greatly appreciated :).
 Check out the [tests/](./tests/) subdirectory for more details.
 

docs/windows.md

@@ -0,0 +1,144 @@
+# Microsoft Windows Details
+
+Repo is primarily developed on Linux with a lot of users on macOS.
+Windows is, unfortunately, not a common platform.
+There is support in repo for Windows, but there might be some rough edges.
+
+Keep in mind that Windows in general is "best effort" and "community supported".
+That means we don't actively test or verify behavior, but rely heavily on users
+to report problems back to us, and to contribute fixes as needed.
+
+[TOC]
+
+## Windows
+
+We only support Windows 10 or newer.
+This is largely due to symlinks not being available in older versions, but it's
+also due to most developers not using Windows.
+
+We will never add code specific to older versions of Windows.
+It might work, but it most likely won't, so please don't bother asking.
+
+## Symlinks
+
+Repo will use symlinks heavily internally.
+On *NIX platforms, this isn't an issue, but Windows makes it a bit difficult.
+
+There are some documents out there for how to do this, but usually the easiest
+answer is to run your shell as an Administrator and invoke repo/git in that.
+
+This isn't a great solution, but Windows doesn't make this easy, so here we are.
+
+### Launch Git Bash
+
+If you install Git Bash (see below), you can launch that with appropriate
+permissions so that all programs "just work".
+
+* Open the Start Menu (i.e. press the ⊞ key).
+* Find/search for "Git Bash".
+* Right click it and select "Run as administrator".
+
+*** note
+**NB**: This environment is only needed when running `repo`, or any specific `git`
+command that might involve symlinks (e.g. `pull` or `checkout`).
+You do not need to run all your commands in here such as your editor.
+***
+
+### Symlinks with GNU tools
+
+If you want to use `ln -s` inside of the default Git/bash shell, you might need
+to export this environment variable:
+```sh
+$ export MSYS="winsymlinks:nativestrict"
+```
+
+Otherwise `ln -s` will copy files and not actually create a symlink.
+This also helps `tar` unpack symlinks, so that's nice.
+
+### References
+
+* https://github.com/git-for-windows/git/wiki/Symbolic-Links
+* https://blogs.windows.com/windowsdeveloper/2016/12/02/symlinks-windows-10/
+
+## Python
+
+You should make sure to be running Python 3.6 or newer under Windows.
+Python 2 might work, but due to already limited platform testing, you should
+only run newer Python versions.
+See our [Python Support](./python-support.md) document for more details.
+
+You can grab the latest Windows installer here:<br>
+https://www.python.org/downloads/release/python-3
+
+## Git
+
+You should install the most recent version of Git for Windows:<br>
+https://git-scm.com/download/win
+
+When installing, make sure to turn on "Enable symbolic links" when prompted.
+
+If you've already installed Git for Windows, you can simply download the latest
+installer from above and run it again.
+It should safely upgrade things in situ for you.
+This is useful if you want to switch the symbolic link option after the fact.
+
+## Shell
+
+We don't have a specific requirement for shell environments when running repo.
+Most developers use MinTTY/bash that's included with the Git for Windows install
+(so see above for installing Git).
+
+Command & Powershell & the Windows Terminal probably work.
+Who knows!
+
+## FAQ
+
+### repo upload always complains about allowing hooks or using --no-verify!
+
+When using `repo upload` in projects that have custom repohooks, you might get
+an error like the following:
+```sh
+$ repo upload
+ERROR: You must allow the pre-upload hook or use --no-verify.
+```
+
+This can be confusing as you never get prompted.
+[MinTTY has a bug][mintty] that breaks isatty checking inside of repo which
+causes repo to never interactively prompt the user which means the upload check
+always fails.
+
+You can workaround this by manually granting consent when uploading.
+Simply add the `--verify` option whenever uploading:
+```sh
+$ repo upload --verify
+```
+
+You will have to specify this flag every time you upload.
+
+[mintty]: https://github.com/mintty/mintty/issues/56
+
+### repohooks always fail with an close_fds error.
+
+When using the [reference repohooks project][repohooks] included in AOSP,
+you might see errors like this when running `repo upload`:
+```sh
+$ repo upload
+ERROR: Traceback (most recent call last):
+  ...
+  File "C:\...\lib\subprocess.py", line 351, in __init__
+    raise ValueError("close_fds is not supported on Windows "
+ValueError: close_fds is not supported on Windows platforms if you redirect stdin/stderr/stdout
+
+Failed to run main() for pre-upload hook; see traceback above.
+```
+
+This error shows up when using Python 2.
+You should upgrade to Python 3 instead (see above).
+
+If you already have Python 3 installed, make sure it's the default version.
+Running `python --version` should say `Python 3`, not `Python 2`.
+If you didn't install the Python versions, or don't have permission to change
+the default version, you can probably workaround this by changing `$PATH` in
+your shell so the Python 3 version is found first.
+
+[repohooks]: https://android.googlesource.com/platform/tools/repohooks

git_config.py

@@ -528,7 +528,7 @@ def GetUrlCookieFile(url, quiet):
         cookiefile = None
         proxy = None
         for line in p.stdout:
-          line = line.strip()
+          line = line.strip().decode('utf-8')
           if line.startswith(cookieprefix):
             cookiefile = os.path.expanduser(line[len(cookieprefix):])
           if line.startswith(proxyprefix):
@@ -540,7 +540,7 @@ def GetUrlCookieFile(url, quiet):
       finally:
         p.stdin.close()
         if p.wait():
-          err_msg = p.stderr.read()
+          err_msg = p.stderr.read().decode('utf-8')
           if ' -print_config' in err_msg:
             pass  # Persistent proxy doesn't support -print_config.
           elif not quiet:

main.py

@@ -27,6 +27,7 @@ import netrc
 import optparse
 import os
 import sys
+import textwrap
 import time
 
 from pyversion import is_python3
@@ -71,8 +72,10 @@ if not is_python3():
   input = raw_input
 
 global_options = optparse.OptionParser(
-                 usage="repo [-p|--paginate|--no-pager] COMMAND [ARGS]"
-                 )
+    usage='repo [-p|--paginate|--no-pager] COMMAND [ARGS]',
+    add_help_option=False)
+global_options.add_option('-h', '--help', action='store_true',
+                          help='show this help message and exit')
 global_options.add_option('-p', '--paginate',
                           dest='pager', action='store_true',
                           help='display command output in the pager')
@@ -123,6 +126,14 @@ class _Repo(object):
       argv = []
     gopts, _gargs = global_options.parse_args(glob)
 
+    if gopts.help:
+      global_options.print_help()
+      commands = ' '.join(sorted(self.commands))
+      wrapped_commands = textwrap.wrap(commands, width=77)
+      print('\nAvailable commands:\n  %s' % ('\n  '.join(wrapped_commands),))
+      print('\nRun `repo help <command>` for command-specific details.')
+      global_options.exit()
+
     return (name, gopts, argv)
 
   def _Run(self, name, gopts, argv):

platform_utils.py

@@ -80,7 +80,7 @@ class FileDescriptorStreams(object):
     """
     raise NotImplementedError
 
-  def _create_stream(fd, dest, std_name):
+  def _create_stream(self, fd, dest, std_name):
     """ Creates a new stream wrapping an existing file descriptor.
     """
     raise NotImplementedError

platform_utils_win32.py

@@ -16,6 +16,7 @@
 
 import errno
 
+from pyversion import is_python3
 from ctypes import WinDLL, get_last_error, FormatError, WinError, addressof
 from ctypes import c_buffer
 from ctypes.wintypes import BOOL, BOOLEAN, LPCWSTR, DWORD, HANDLE, POINTER, c_ubyte
@@ -179,7 +180,7 @@ def readlink(path):
   if reparse_point_handle == INVALID_HANDLE_VALUE:
     _raise_winerror(
         get_last_error(),
-        'Error opening symblic link \"%s\"'.format(path))
+        'Error opening symbolic link \"%s\"'.format(path))
   target_buffer = c_buffer(MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
   n_bytes_returned = DWORD()
   io_result = DeviceIoControl(reparse_point_handle,
@@ -194,7 +195,7 @@ def readlink(path):
   if not io_result:
     _raise_winerror(
         get_last_error(),
-        'Error reading symblic link \"%s\"'.format(path))
+        'Error reading symbolic link \"%s\"'.format(path))
   rdb = REPARSE_DATA_BUFFER.from_buffer(target_buffer)
   if rdb.ReparseTag == IO_REPARSE_TAG_SYMLINK:
     return _preserve_encoding(path, rdb.SymbolicLinkReparseBuffer.PrintName)
@@ -203,11 +204,15 @@ def readlink(path):
   # Unsupported reparse point type
   _raise_winerror(
       ERROR_NOT_SUPPORTED,
-      'Error reading symblic link \"%s\"'.format(path))
+      'Error reading symbolic link \"%s\"'.format(path))
 
 
 def _preserve_encoding(source, target):
   """Ensures target is the same string type (i.e. unicode or str) as source."""
+
+  if is_python3():
+    return target
+
   if isinstance(source, unicode):
     return unicode(target)
   return str(target)

project.py

@@ -1065,7 +1065,7 @@ class Project(object):
     """Prints the status of the repository to stdout.
 
     Args:
-      output: If specified, redirect the output to this object.
+      output_redir: If specified, redirect the output to this object.
       quiet:  If True then only print the project name.  Do not print
               the modified files, branch name, etc.
     """
@@ -1989,7 +1989,7 @@ class Project(object):
       gitmodules_lines = []
       fd, temp_gitmodules_path = tempfile.mkstemp()
       try:
-        os.write(fd, p.stdout)
+        os.write(fd, p.stdout.encode('utf-8'))
         os.close(fd)
         cmd = ['config', '--file', temp_gitmodules_path, '--list']
         p = GitCommand(None, cmd, capture_stdout=True, capture_stderr=True,
@@ -2235,16 +2235,6 @@ class Project(object):
       cmd.append('--update-head-ok')
     cmd.append(name)
 
-    spec = []
-
-    # If using depth then we should not get all the tags since they may
-    # be outside of the depth.
-    if no_tags or depth:
-      cmd.append('--no-tags')
-    else:
-      cmd.append('--tags')
-      spec.append(str((u'+refs/tags/*:') + remote.ToLocal('refs/tags/*')))
-
     if force_sync:
       cmd.append('--force')
 
@@ -2254,6 +2244,7 @@ class Project(object):
     if submodules:
       cmd.append('--recurse-submodules=on-demand')
 
+    spec = []
     if not current_branch_only:
       # Fetch whole repo
       spec.append(str((u'+refs/heads/*:') + remote.ToLocal('refs/heads/*')))
@@ -2261,19 +2252,36 @@ class Project(object):
       spec.append('tag')
       spec.append(tag_name)
 
-    if not self.manifest.IsMirror:
+    if self.manifest.IsMirror and not current_branch_only:
+      branch = None
+    else:
       branch = self.revisionExpr
-      if is_sha1 and depth and git_require((1, 8, 3)):
-        # Shallow checkout of a specific commit, fetch from that commit and not
-        # the heads only as the commit might be deeper in the history.
-        spec.append(branch)
-      else:
-        if is_sha1:
-          branch = self.upstream
-        if branch is not None and branch.strip():
-          if not branch.startswith('refs/'):
-            branch = R_HEADS + branch
-          spec.append(str((u'+%s:' % branch) + remote.ToLocal(branch)))
+    if (not self.manifest.IsMirror and is_sha1 and depth
+        and git_require((1, 8, 3))):
+      # Shallow checkout of a specific commit, fetch from that commit and not
+      # the heads only as the commit might be deeper in the history.
+      spec.append(branch)
+    else:
+      if is_sha1:
+        branch = self.upstream
+      if branch is not None and branch.strip():
+        if not branch.startswith('refs/'):
+          branch = R_HEADS + branch
+        spec.append(str((u'+%s:' % branch) + remote.ToLocal(branch)))
+
+    # If mirroring repo and we cannot deduce the tag or branch to fetch, fetch
+    # whole repo.
+    if self.manifest.IsMirror and not spec:
+      spec.append(str((u'+refs/heads/*:') + remote.ToLocal('refs/heads/*')))
+
+    # If using depth then we should not get all the tags since they may
+    # be outside of the depth.
+    if no_tags or depth:
+      cmd.append('--no-tags')
+    else:
+      cmd.append('--tags')
+      spec.append(str((u'+refs/tags/*:') + remote.ToLocal('refs/tags/*')))
+
     cmd.extend(spec)
 
     ok = False
@@ -2390,7 +2398,7 @@ class Project(object):
         platform_utils.remove(tmpPath)
     with GetUrlCookieFile(srcUrl, quiet) as (cookiefile, proxy):
       if cookiefile:
-        cmd += ['--cookie', cookiefile, '--cookie-jar', cookiefile]
+        cmd += ['--cookie', cookiefile]
       if proxy:
         cmd += ['--proxy', proxy]
       elif 'http_proxy' in os.environ and 'darwin' == sys.platform:

repo

@@ -16,7 +16,9 @@ import os
 REPO_URL = os.environ.get('REPO_URL', None)
 if not REPO_URL:
   REPO_URL = 'https://gerrit.googlesource.com/git-repo'
-REPO_REV = 'stable'
+REPO_REV = os.environ.get('REPO_REV')
+if not REPO_REV:
+  REPO_REV = 'repo-1'
 
 # Copyright (C) 2008 Google Inc.
 #
@@ -33,7 +35,7 @@ REPO_REV = 'stable'
 # limitations under the License.
 
 # increment this whenever we make important changes to this script
-VERSION = (1, 26)
+VERSION = (1, 27)
 
 # increment this if the MAINTAINER_KEYS block is modified
 KEYRING_VERSION = (1, 2)
@@ -235,10 +237,10 @@ group.add_option('--no-tags',
 group = init_optparse.add_option_group('repo Version options')
 group.add_option('--repo-url',
                  dest='repo_url',
-                 help='repo repository location', metavar='URL')
+                 help='repo repository location ($REPO_URL)', metavar='URL')
 group.add_option('--repo-branch',
                  dest='repo_branch',
-                 help='repo branch or revision', metavar='REVISION')
+                 help='repo branch or revision ($REPO_REV)', metavar='REVISION')
 group.add_option('--no-repo-verify',
                  dest='no_repo_verify', action='store_true',
                  help='do not verify repo source code')
@@ -366,15 +368,18 @@ def _Init(args, gitc_init=False):
 
   _CheckGitVersion()
   try:
-    if NeedSetupGnuPG():
-      can_verify = SetupGnuPG(opt.quiet)
+    if opt.no_repo_verify:
+      do_verify = False
     else:
-      can_verify = True
+      if NeedSetupGnuPG():
+        do_verify = SetupGnuPG(opt.quiet)
+      else:
+        do_verify = True
 
     dst = os.path.abspath(os.path.join(repodir, S_repo))
     _Clone(url, dst, opt.quiet, not opt.no_clone_bundle)
 
-    if can_verify and not opt.no_repo_verify:
+    if do_verify:
       rev = _Verify(dst, branch, opt.quiet)
     else:
       rev = 'refs/remotes/origin/%s^0' % branch

run_tests

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 # -*- coding:utf-8 -*-
 # Copyright 2019 The Android Open Source Project
 #
@@ -27,14 +27,13 @@ import sys
 def run_pytest(cmd, argv):
   """Run the unittests via |cmd|."""
   try:
-    subprocess.check_call([cmd] + argv)
-    return 0
+    return subprocess.call([cmd] + argv)
   except OSError as e:
     if e.errno == errno.ENOENT:
       print('%s: unable to run `%s`: %s' % (__file__, cmd, e), file=sys.stderr)
       print('%s: Try installing pytest: sudo apt-get install python-pytest' %
             (__file__,), file=sys.stderr)
-      return 1
+      return 127
     else:
       raise
 

setup.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+# -*- coding:utf-8 -*-
+# Copyright 2019 The Android Open Source Project
+#
+# 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.
+
+"""Python packaging for repo."""
+
+from __future__ import print_function
+
+import os
+import setuptools
+
+
+TOPDIR = os.path.dirname(os.path.abspath(__file__))
+
+
+# Rip out the first intro paragraph.
+with open(os.path.join(TOPDIR, 'README.md')) as fp:
+    lines = fp.read().splitlines()[2:]
+    end = lines.index('')
+    long_description = ' '.join(lines[0:end])
+
+
+# https://packaging.python.org/tutorials/packaging-projects/
+setuptools.setup(
+    name='repo',
+    version='1.13.8',
+    maintainer='Various',
+    maintainer_email='repo-discuss@googlegroups.com',
+    description='Repo helps manage many Git repositories',
+    long_description=long_description,
+    long_description_content_type='text/plain',
+    url='https://gerrit.googlesource.com/git-repo/',
+    project_urls={
+        'Bug Tracker': 'https://bugs.chromium.org/p/gerrit/issues/list?q=component:repo',
+    },
+    # https://pypi.org/classifiers/
+    classifiers=[
+        'Development Status :: 6 - Mature',
+        'Environment :: Console',
+        'Intended Audience :: Developers',
+        'License :: OSI Approved :: Apache Software License',
+        'Natural Language :: English',
+        'Operating System :: MacOS :: MacOS X',
+        'Operating System :: Microsoft :: Windows :: Windows 10',
+        'Operating System :: POSIX :: Linux',
+        'Topic :: Software Development :: Version Control :: Git',
+    ],
+    # We support Python 2.7 and Python 3.6+.
+    python_requires='>=2.7, ' + ', '.join('!=3.%i.*' % x for x in range(0, 6)),
+    packages=['subcmds'],
+)

subcmds/forall.py

@@ -366,7 +366,7 @@ def DoWork(project, mirror, opt, cmd, shell, cnt, config):
     while not s_in.is_done:
       in_ready = s_in.select()
       for s in in_ready:
-        buf = s.read()
+        buf = s.read().decode()
         if not buf:
           s.close()
           s_in.remove(s)

subcmds/gitc_init.py

@@ -50,7 +50,7 @@ use for this GITC client.
 """
 
   def _Options(self, p):
-    super(GitcInit, self)._Options(p)
+    super(GitcInit, self)._Options(p, gitc_init=True)
     g = p.add_option_group('GITC options')
     g.add_option('-f', '--manifest-file',
                  dest='manifest_file',

subcmds/help.py

@@ -33,11 +33,8 @@ class Help(PagedCommand, MirrorSafeCommand):
 Displays detailed usage information about a command.
 """
 
-  def _PrintAllCommands(self):
-    print('usage: repo COMMAND [ARGS]')
-    print('The complete list of recognized repo commands are:')
-    commandNames = list(sorted(self.commands))
-
+  def _PrintCommands(self, commandNames):
+    """Helper to display |commandNames| summaries."""
     maxlen = 0
     for name in commandNames:
       maxlen = max(maxlen, len(name))
@@ -50,6 +47,12 @@ Displays detailed usage information about a command.
       except AttributeError:
         summary = ''
       print(fmt % (name, summary))
+
+  def _PrintAllCommands(self):
+    print('usage: repo COMMAND [ARGS]')
+    print('The complete list of recognized repo commands are:')
+    commandNames = list(sorted(self.commands))
+    self._PrintCommands(commandNames)
     print("See 'repo help <command>' for more information on a "
           'specific command.')
 
@@ -71,19 +74,8 @@ Displays detailed usage information about a command.
     commandNames = list(sorted([name
                     for name, command in self.commands.items()
                     if command.common and gitc_supported(command)]))
+    self._PrintCommands(commandNames)
 
-    maxlen = 0
-    for name in commandNames:
-      maxlen = max(maxlen, len(name))
-    fmt = '  %%-%ds  %%s' % maxlen
-
-    for name in commandNames:
-      command = self.commands[name]
-      try:
-        summary = command.helpSummary.strip()
-      except AttributeError:
-        summary = ''
-      print(fmt % (name, summary))
     print(
 "See 'repo help <command>' for more information on a specific command.\n"
 "See 'repo help --all' for a complete list of recognized commands.")

subcmds/info.py

@@ -103,6 +103,10 @@ class Info(PagedCommand):
         self.headtext(currentBranch)
         self.out.nl()
 
+      self.heading("Manifest revision: ")
+      self.headtext(p.revisionExpr)
+      self.out.nl()
+
       localBranches = list(p.GetBranches().keys())
       self.heading("Local Branches: ")
       self.redtext(str(len(localBranches)))

subcmds/init.py

@@ -81,7 +81,7 @@ manifest, a subsequent `repo sync` (or `repo sync -d`) is necessary
 to update the working directory files.
 """
 
-  def _Options(self, p):
+  def _Options(self, p, gitc_init=False):
     # Logging
     g = p.add_option_group('Logging options')
     g.add_option('-q', '--quiet',
@@ -96,7 +96,12 @@ to update the working directory files.
     g.add_option('-b', '--manifest-branch',
                  dest='manifest_branch',
                  help='manifest branch or revision', metavar='REVISION')
-    g.add_option('--current-branch',
+    cbr_opts = ['--current-branch']
+    # The gitc-init subcommand allocates -c itself, but a lot of init users
+    # want -c, so try to satisfy both as best we can.
+    if not gitc_init:
+      cbr_opts += ['-c']
+    g.add_option(*cbr_opts,
                  dest='current_branch_only', action='store_true',
                  help='fetch only current manifest branch from server')
     g.add_option('-m', '--manifest-name',

tox.ini

@@ -0,0 +1,22 @@
+# Copyright 2019 The Android Open Source Project
+#
+# 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.
+
+# https://tox.readthedocs.io/
+
+[tox]
+envlist = py27, py36, py37, py38
+
+[testenv]
+deps = pytest
+commands = {toxinidir}/run_tests