Issue 4373 - Made jshydra compatible with Python 3

utils.py

-# coding: utf-8
-
 # This Source Code is subject to the terms of the Mozilla Public License
 # version 2.0 (the "License"). You can obtain a copy of the License at
 # http://mozilla.org/MPL/2.0/.
 
-from contextlib import closing
 import os
 import platform
-from StringIO import StringIO
-import sys
-import urllib
+import io
 import zipfile
 
-JSSHELL_DIR = "mozilla-esr31"
-JSSHELL_URL = ("https://ftp.mozilla.org/pub/mozilla.org/firefox/nightly"
-               "/2015/02/2015-02-25-00-22-19-%s/jsshell-%%s.zip" % JSSHELL_DIR)
+try:
+    from urllib.request import urlopen
+except ImportError:
+    import urllib2

[Sebastian Noack, 2016/08/30 11:44:39]

It seems more resonable to fallback to urllib2 (rather than urllib) on Python 2,
since it is closer to the semantics of urllib.request on Python 3, e.g. it
raises when encountering bad HTTP responses.

[Vasily Kuznetsov, 2016/08/30 13:16:30]

Acknowledged.

+    import contextlib
+
+    def urlopen(*args, **kwargs):
+        return contextlib.closing(urllib2.urlopen(*args, **kwargs))
+
+JSSHELL_DIR = 'mozilla-esr31'
+JSSHELL_URL = ('https://ftp.mozilla.org/pub/mozilla.org/firefox/nightly'
+               '/2015/02/2015-02-25-00-22-19-{}'
+               '/jsshell-{{}}.zip'.format(JSSHELL_DIR))
 
 JSSHELL_SUPPORTED_PLATFORMS = {
-    "win32": "win32",
-    "linux2": {
-        "i686": "linux-i686",
-        "x86_64": "linux-x86_64"
+    'Windows': 'win32',
+    'Linux': {
+        'i686': 'linux-i686',
+        'x86_64': 'linux-x86_64'
     },
-    "darwin": "mac"
+    'Darwin': 'mac'
 }
 
 
 def ensureJSShell():
     path = os.environ.get('SPIDERMONKEY_BINARY')
     if path and os.path.isfile(path):
         return path
 
     baseDir = os.path.dirname(__file__)
+    system = platform.system()
 
     try:
-        build = JSSHELL_SUPPORTED_PLATFORMS[sys.platform]
+        build = JSSHELL_SUPPORTED_PLATFORMS[system]
         if isinstance(build, dict):
             build = build[platform.machine()]
     except KeyError:
-        raise Exception('Platform %s (%s) not supported by JS shell' % (
-            sys.platform, platform.machine()
+        raise Exception('Platform {} ({}) not supported by JS shell'.format(
+            system, platform.machine()
         ))
 
     shell_dir = os.path.join(baseDir, JSSHELL_DIR + "-" + build)
     if not os.path.exists(shell_dir):
         os.makedirs(shell_dir)
-    if sys.platform == 'win32':
+    if system == 'Windows':
         path = os.path.join(shell_dir, 'js.exe')
     else:
         path = os.path.join(shell_dir, 'js')
 
     if os.path.exists(path):
         return path
 
-    with closing(urllib.urlopen(JSSHELL_URL % build)) as response:
+    with urlopen(JSSHELL_URL.format(build)) as response:
         data = response.read()
 
-    with zipfile.ZipFile(StringIO(data)) as zip:
-        zip.extractall(shell_dir)
+    with zipfile.ZipFile(io.BytesIO(data)) as archive:
+        archive.extractall(shell_dir)
 
     if not os.path.exists(path):
         raise Exception('Downloaded package didn\'t contain JS shell executable')
 
     try:
-        os.chmod(path, 0700)
+        os.chmod(path, 0o700)
     except:
         pass
 
     return path