Make test_env compatible with python 2 & 3

Use the vendored copy of the `six` library to make this code work across
Python versions.

Bug: 942720
Change-Id: I4bdb1032ed8e89e733b929eb13ada54efeb3b019
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2229335
Commit-Queue: Chris McDonald <cjmcdonald@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774934}

testing/test_env.py

-#!/usr/bin/env python2
+#!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Sets environment variables needed to run a chromium unit test."""
 
+from __future__ import print_function
 import io
 import os
 import signal
@@ -13,6 +14,13 @@ import subprocess
 import sys
 import time
 
+SIX_DIR = os.path.join(
+    os.path.dirname(os.path.dirname(os.path.abspath(__file__))), 'third_party',
+    'six')
+sys.path.insert(0, SIX_DIR)
+
+import six
+
 # This is hardcoded to be src/ relative to this script.
 ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 
@@ -167,12 +175,12 @@ def symbolize_snippets_in_json(cmd, env):
     p = subprocess.Popen(symbolize_command, stderr=subprocess.PIPE, env=env)
     (_, stderr) = p.communicate()
   except OSError as e:
-    print >> sys.stderr, 'Exception while symbolizing snippets: %s' % e
+    print('Exception while symbolizing snippets: %s' % e, file=sys.stderr)
     raise
 
   if p.returncode != 0:
-    print >> sys.stderr, "Error: failed to symbolize snippets in JSON:\n"
-    print >> sys.stderr, stderr
+    print("Error: failed to symbolize snippets in JSON:\n", file=sys.stderr)
+    print(stderr, file=sys.stderr)
     raise subprocess.CalledProcessError(p.returncode, symbolize_command)
 
 
@@ -345,7 +353,7 @@ def run_executable(cmd, env, stdoutfile=None):
   print('Additional test environment:\n%s\n'
         'Command: %s\n' % (
         '\n'.join('    %s=%s' %
-            (k, v) for k, v in sorted(env_to_print.iteritems())),
+            (k, v) for k, v in sorted(six.iteritems(env_to_print))),
         ' '.join(cmd)))
   sys.stdout.flush()
   env.update(extra_env or {})
@@ -371,7 +379,7 @@ def run_executable(cmd, env, stdoutfile=None):
     else:
       return run_command(cmd, env=env, log=False)
   except OSError:
-    print >> sys.stderr, 'Failed to start %s' % cmd
+    print('Failed to start %s' % cmd, file=sys.stderr)
     raise
 
 

testing/test_env_test_script.py

@@ -5,14 +5,14 @@
 
 """Script for use in test_env unittests."""
 
-import os
+from __future__ import print_function
 import signal
 import sys
 import time
 
 
-def print_signal(sig, *_):
-  print 'Signal :{}'.format(sig)
+def print_signal(sig, *_args):
+  print('Signal :{}'.format(sig))
 
 
 if __name__ == '__main__':

testing/test_env_unittest.py

@@ -17,20 +17,29 @@ import sys
 import time
 import unittest
 
-
-TEST_SCRIPT = 'test_env_user_script.py'
+HERE = os.path.dirname(os.path.abspath(__file__))
+TEST_SCRIPT = os.path.join(HERE, 'test_env_user_script.py')
 
 
 def launch_process_windows(args):
+  # The `universal_newlines` option is equivalent to `text` in Python 3.
   return subprocess.Popen(
-      [sys.executable, TEST_SCRIPT] + args, stdout=subprocess.PIPE,
-      stderr=subprocess.STDOUT, env=os.environ.copy(),
-      creationflags=subprocess.CREATE_NEW_PROCESS_GROUP)
+      [sys.executable, TEST_SCRIPT] + args,
+      stdout=subprocess.PIPE,
+      stderr=subprocess.STDOUT,
+      env=os.environ.copy(),
+      creationflags=subprocess.CREATE_NEW_PROCESS_GROUP,
+      universal_newlines=True)
+
 
 def launch_process_nonwindows(args):
+  # The `universal_newlines` option is equivalent to `text` in Python 3.
   return subprocess.Popen(
-      [sys.executable, TEST_SCRIPT] + args, stdout=subprocess.PIPE,
-      stderr=subprocess.STDOUT, env=os.environ.copy())
+      [sys.executable, TEST_SCRIPT] + args,
+      stdout=subprocess.PIPE,
+      stderr=subprocess.STDOUT,
+      env=os.environ.copy(),
+      universal_newlines=True)
 
 
 def read_subprocess_message(proc, starts_with):
@@ -58,7 +67,7 @@ class SignalingWindowsTest(unittest.TestCase):
     proc = launch_process_windows([])
     send_and_wait(proc, signal.CTRL_BREAK_EVENT)
     sig = read_subprocess_message(proc, 'Signal :')
-    self.assertEqual(sig, str(signal.SIGBREAK))
+    self.assertEqual(sig, str(int(signal.SIGBREAK)))
 
 
 class SignalingNonWindowsTest(unittest.TestCase):
@@ -72,13 +81,13 @@ class SignalingNonWindowsTest(unittest.TestCase):
     proc = launch_process_nonwindows([])
     send_and_wait(proc, signal.SIGTERM)
     sig = read_subprocess_message(proc, 'Signal :')
-    self.assertEqual(sig, str(signal.SIGTERM))
+    self.assertEqual(sig, str(int(signal.SIGTERM)))
 
   def test_send_sigint(self):
     proc = launch_process_nonwindows([])
     send_and_wait(proc, signal.SIGINT)
     sig = read_subprocess_message(proc, 'Signal :')
-    self.assertEqual(sig, str(signal.SIGINT))
+    self.assertEqual(sig, str(int(signal.SIGINT)))
 
 
 if __name__ == '__main__':

testing/test_env_user_script.py

@@ -5,8 +5,12 @@
 
 """Script for use in test_env unittests."""
 
+import os
+
 import test_env
 
+HERE = os.path.dirname(os.path.abspath(__file__))
+TEST_SCRIPT = os.path.join(HERE, 'test_env_test_script.py')
 
 if __name__ == '__main__':
-  test_env.run_command(['python', 'test_env_test_script.py'])
+  test_env.run_command([TEST_SCRIPT])