Polymer: Update find_unused_elements.py

third_party/polymer/v1_0/find_unused_elements.py

Index: third_party/polymer/v1_0/find_unused_elements.py
diff --git a/third_party/polymer/v1_0/find_unused_elements.py b/third_party/polymer/v1_0/find_unused_elements.py
index 5dbacdbdcbcec33a1c587eb987f182fc234e3025..bc377c1c1d8ec03dceefd8f19de026f5a57b428c 100644
--- a/third_party/polymer/v1_0/find_unused_elements.py
+++ b/third_party/polymer/v1_0/find_unused_elements.py
@@ -11,7 +11,14 @@ to check if other elements have become unused.
 import os
 import re
 import subprocess
+import sys
+import tempfile
 
+_HERE_PATH = os.path.dirname(__file__)
+_SRC_PATH = os.path.normpath(os.path.join(_HERE_PATH, '..', '..', '..'))
+sys.path.append(os.path.join(_SRC_PATH, 'third_party', 'node'))

[michaelpg, 2017/06/05 19:22:36]

remove uglify check in reproduce.sh

[dpapad, 2017/06/05 19:42:02]

Done.

+import node
+import node_modules
 
 class UnusedElementsDetector(object):
   """Finds unused Polymer elements."""
@@ -58,8 +65,16 @@ class UnusedElementsDetector(object):
     text = re.sub('<if .*?>', '', text, flags=re.IGNORECASE)
     text = re.sub('</if>', '', text, flags=re.IGNORECASE)
 
-    proc = subprocess.Popen(['uglifyjs', filename], stdout=subprocess.PIPE)

[Dan Beam, 2017/06/02 21:49:08]

can we change to subprocess2 and use stderr=subprocess.VOID instead?

https://cs.chromium.org/chromium/build/tests/masters_util.py?type=cs&q=stderr...

[dpapad, 2017/06/05 19:22:09]

We probably could (have not tried yet), but importing subproccess2 is a bit
involved, see lines
https://cs.chromium.org/chromium/build/tests/masters_util.py?type=cs&q=stderr....

Do you still think this is a better idea than just writing to a temp file? If
not, I might not get to it today.

[dpapad, 2017/06/06 21:39:55]

This is not necessary anymore. I rebased this CL after
https://codereview.chromium.org/2921793002 (which changes uglifyjs to
uglify-es), and there is no need to use the temporary file anymore, see patch
#4.

-    return proc.stdout.read()
+    # Need to write the output to a temporary file to avoid
+    # https://github.com/mishoo/UglifyJS2/issues/641 which has been fixed after
+    # version 2.4.21.
+    # TODO(dpapad): Chromium currently uses 2.4.10, update to latest version.
+    with tempfile.NamedTemporaryFile(mode='wt+') as tmp:
+      node.RunNode([
+          node_modules.PathToUglifyJs(), filename, '--output', tmp.name])
+      output = tmp.read()
+
+    return output
 
   @staticmethod
   def __StripComments(filename):
@@ -133,11 +148,6 @@ class UnusedElementsDetector(object):
           if not filename.endswith('.html') and not filename.endswith('.js'):
             continue
 
-          # Skip generated files that may include the element source.
-          if filename in ('crisper.js', 'vulcanized.html',
-                          'app.crisper.js', 'app.vulcanized.html'):
-            continue
-
           with open(os.path.join(dirpath, filename)) as f:
             text = f.read()
           if not re.search('/%s/' % element_dir, text):