Upgrade clean-css

In order to upgrade clean-css it is necessary to import the filter
definition from the future version of webassets. This version takes
extra arguments in the filter configuration, allowing us to disable
the advanced optimizations that became the default in 3.0+ but that
breaks some of our styles.

conf/production.ini

@@ -56,6 +56,7 @@ webassets.static_view: True
 webassets.browserify_bin: ./node_modules/.bin/browserify
 webassets.browserify_extra_args: --extension=.coffee --transform coffeeify
 webassets.cleancss_bin: ./node_modules/.bin/cleancss
+webassets.cleancss_extra_args: --skip-advanced --skip-rebase
 webassets.uglifyjs_bin: ./node_modules/.bin/uglifyjs
 
 

h/assets.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+import os
 import re
 
 from deform.field import Field
@@ -36,6 +37,45 @@ def input(self, in_, out, **kwargs):
 register_filter(Browserify)
 
 
+# The release versions of webassets upstream don't support extra arguments yet.
+class CleanCSS(ExternalTool):
+    """
+    Minify css using `Clean-css <https://github.com/GoalSmashers/clean-css/>`_.
+
+    Clean-css is an external tool written for NodeJS; this filter assumes that
+    the ``cleancss`` executable is in the path. Otherwise, you may define
+    a ``CLEANCSS_BIN`` setting.
+
+    Additional options may be passed to ``cleancss`` binary using the setting
+    ``CLEANCSS_EXTRA_ARGS``, which expects a list of strings.
+    """
+
+    name = 'cleancss'
+    options = {
+        'binary': 'CLEANCSS_BIN',
+        'extra_args': 'CLEANCSS_EXTRA_ARGS',
+    }
+
+    def output(self, _in, out, **kw):
+        args = [self.binary or 'cleancss']
+        if self.extra_args:
+            if isinstance(self.extra_args, basestring):
+                self.extra_args = self.extra_args.split()
+            args.extend(self.extra_args)
+        self.subprocess(args, out, _in)
+
+    def input(self, _in, out, **kw):
+        args = [self.binary or 'cleancss', '--root',
+                os.path.dirname(kw['source_path'])]
+        if self.extra_args:
+            if isinstance(self.extra_args, basestring):
+                self.extra_args = self.extra_args.split()
+            args.extend(self.extra_args)
+        self.subprocess(args, out, _in)
+
+register_filter(CleanCSS)
+
+
 class WebassetsResourceRegistry(object):
 
     def __init__(self, env):

package.json

@@ -19,7 +19,7 @@
     "browserify": "^9.0.3",
     "browserify-ngannotate": "^1.0.1",
     "browserify-shim": "^3.8.3",
-    "clean-css": "2.2.2",
+    "clean-css": "3.3.9",
     "coffee-script": "1.7.1",
     "coffeeify": "^1.0.0",
     "diff-match-patch": "^1.0.0",