web_dev_style: ignore --css-vars from alphabetical ordering requirement

chrome/browser/web_dev_style/css_checker.py

 # Copyright 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.
 
 """Presubmit script for Chromium WebUI resources.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools, and see
 http://www.chromium.org/developers/web-development-style-guide for the rules
 we're checking against here.
@@ skipping 15 matching lines @@
       return (len(s) == 6 and s[0] == s[1] and s[2] == s[3] and s[4] == s[5])
 
     def _is_gray(s):
       return s[0] == s[1] == s[2] if len(s) == 3 else s[0:2] == s[2:4] == s[4:6]
 
     def _remove_all(s):
       s = _remove_grit(s)
       s = _remove_ats(s)
       s = _remove_comments(s)
       s = _remove_template_expressions(s)
-      s = _remove_mixins(s)
+      s = _remove_valid_vars(s)
       return s
 
     def _extract_inline_style(s):
       return '\n'.join(re.findall(r'<style\b[^>]*>([^<]*)<\/style>', s))
 
     def _remove_ats(s):
       at_reg = re.compile(r"""
           @(?!apply)(?!\d+x\b)    # @at-keyword, not (apply|2x)
           \w+[^'"]*?{             # selector junk {
           (.*{.*?})+              # inner { curly } blocks, rules, and selector
           .*?}                    # stuff up to the first end curly }
           """,
           re.DOTALL | re.VERBOSE)
       return at_reg.sub('\\1', s)
 
     def _remove_comments(s):
       return re.sub(re.compile(r'/\*.*?\*/', re.DOTALL), '', s)
 
-    def _remove_mixins(s):
-      return re.sub(re.compile(r'--[\d\w-]+: {.*?};', re.DOTALL), '', s)

[dschuyler, 2016/09/19 21:23:28]

With this no longer being done, it looks like
something like this, "--foo: {\n a: b;\n c: d;\n};\n"
would result in, '\n c: d;\n};\n' based on the new
_remove_valid_vars().

-
-    def _remove_template_expressions(s):
-      return re.sub(re.compile(r'\$i18n(Raw)?{[^}]*}', re.DOTALL), '', s)
-
     def _remove_grit(s):
       grit_reg = re.compile(r"""
           <if[^>]+>.*?<\s*/\s*if[^>]*>|  # <if> contents </if>
           <include[^>]+>                 # <include>
           """,
           re.DOTALL | re.VERBOSE)
       return re.sub(grit_reg, '', s)
 
+    def _remove_template_expressions(s):
+      return re.sub(re.compile(r'\$i18n(Raw)?{[^}]*}', re.DOTALL), '', s)
+
+    mixin_shim_reg = '[\w\d-]+_-_[\w\d-]+'
+
+    def _remove_valid_vars(s):
+      valid_var_reg = '--(?!' + mixin_shim_reg + ')[\d\w-]+\s*:\s*[^;]+?;'
+      return re.sub(re.compile(valid_var_reg, re.DOTALL), '', s)

[dschuyler, 2016/09/19 21:23:28]

About the regex changes:
- having \d and \w in the same [] is be redundant (previously mentioned).
- I think the re.DOTALL doesn't affect a regex that doesn't have any dots '.'
- If the re.DOTALL is removed, the re.compile would become redundant.
- the \s* near the end looks redundant with the [^;]+, since 'not ;' would
include \s.
- the ? near the end "[^;]+?;" (while harmless) doesn't appear to be useful
- if the ? was trying to make the "[^;]+" optional, then either of these would
work as alternatives: "([^;]+)?" or "[^;]*"
- the backslashes happen to be working out ok with \w and \s, but I think it
would be more correct to create raw (r'') strings

Does something like the following do what is needed?

   mixin_shim_reg = r'[\w-]+_-_[\w-]+'

   def _remove_valid_vars(s):
      valid_var_reg = '--(?!' + mixin_shim_reg + r')[\w-]+\s*:[^;]*;'
      return re.sub(valid_var_reg, '', s)

[Dan Beam, 2016/09/22 02:13:26]

Done.
added back a .
i kept it, but turns out you can just pass flags= as well.  changed all _remove*
methods to just use re.sub(..., flags=...) rather than compile()
Done.
Done.
no, we talked about this.  was supposed to be non-greedy.  it probably doesn't
matter.  dropped other than for .*?
Done.
kind of, but like you mentioned (somewhere else?) [^;] can only be satisfied
until the first ;.  inside of multi-rule mixins, this is problematic.

so i've essentially created 2 branches: if we find a {.*?}, remove that, else
look until ;

+
     def _rgb_from_hex(s):
       if len(s) == 3:
         r, g, b = s[0] + s[0], s[1] + s[1], s[2] + s[2]
       else:
         r, g, b = s[0:2], s[2:4], s[4:6]
       return int(r, base=16), int(g, base=16), int(b, base=16)
 
     def _strip_prefix(s):
       return re.sub(r'^-(?:o|ms|moz|khtml|webkit)-', '', s)
 
@@ skipping 84 matching lines @@
       return small_seconds_reg.search(line)
 
     def suggest_ms_from_s(line):
       ms = int(float(small_seconds_reg.search(line).group(1)) * 1000)
       return ' (replace with %dms)' % ms
 
     def no_data_uris_in_source_files(line):
       return re.search(r'\(\s*\s*data:', line)
 
     def no_mixin_shims(line):
-      return re.search('\-\-[\w\-]+_\-_[\w\-]+\s*:', line)
+      return re.search('--' + mixin_shim_reg + '\s*:', line)
 
     def no_quotes_in_url(line):
       return re.search('url\s*\(\s*["\']', line, re.IGNORECASE)
 
     def one_rule_per_line(line):
       one_rule_reg = re.compile(r"""
           [\w-](?<!data):  # a rule: but no data URIs
           (?!//)[^;]+;     # value; ignoring colons in protocols:// and };
           \s*[^ }]\s*      # any non-space after the end colon
           """,
@@ skipping 237 matching lines @@
                 error += check['after'](line)
               check_errors.append(error)
           if len(check_errors) > 0:
             file_errors.append('- %s\n%s' %
                 (check['desc'], '\n'.join(check_errors)))
       if file_errors:
         results.append(self.output_api.PresubmitPromptWarning(
             '%s:\n%s' % (f[0], '\n\n'.join(file_errors))))
 
     return results