Issue 6945 - Add script to make filter list diffs

abp/filters/diff_script.py

 # This file is part of Adblock Plus <https://adblockplus.org/>,
 # Copyright (C) 2006-present eyeo GmbH
 #
 # Adblock Plus is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 3 as
 # published by the Free Software Foundation.
 #
 # Adblock Plus is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
 
 """Command line script for rendering Adblock Plus filter list diffs."""
 
 from __future__ import print_function
+
 import argparse

[Sebastian Noack, 2018/09/21 11:51:21]

Nit: __future__ imports are special, so I would seperate them from corelib
imports with a blank line.

[rhowell, 2018/09/24 22:05:21]

Done.

 import io
 import sys
 
-from .sources import NotFound
 from .renderer import render_diff
+
 __all__ = ['main']

[Sebastian Noack, 2018/09/21 11:51:21]

Nit: There should be blank link above, here as well.

[rhowell, 2018/09/24 22:05:21]

Done.

 
 
 def parse_args():
     parser = argparse.ArgumentParser(description='Render a filter list diff.')
     parser.add_argument(
         'base', help='the older filter list that needs to be updated',
         nargs='?')
     parser.add_argument(
         'latest', help='the most recent version of the filter list',
         nargs='?')
     parser.add_argument(
         'outfile', help='output file for filter list diff',
         default='-', nargs='?')
     return parser.parse_args()
 
 
-def main(args_in=None):

[Sebastian Noack, 2018/09/21 11:51:20]

The args_in argument seems to be unused, and I don't see such an argument in
render_script.py either.

[rhowell, 2018/09/24 22:05:21]

Oops, I should've removed this when removing the extraneous test on the last
patch set. Done!

-    """Entry point for the diff rendering script (diffrender)."""
+def main():
+    """Entry point for the diff rendering script (fldiff)."""
     args = parse_args()
 
-    with io.open(args.base, 'r') as base, io.open(args.latest, 'r') as latest:

[Sebastian Noack, 2018/09/21 11:51:21]

Unlike below, you don't specify an encoding when calling io.open() here. On
Linux (at least) it will still work as intended as it defaults to UTF-8. But
according to the documentation the default encoding depends on the platform. So
we should explicitly specify encoding='utf-8' here as well.

[rhowell, 2018/09/24 22:05:21]

Done.

-        try:
-            lines = render_diff(base, latest)
-            if args.outfile == '-':
-                outfile = io.open(sys.stdout.fileno(), 'w',
-                                  closefd=False,
-                                  encoding=sys.stdout.encoding or 'utf-8')
-            else:
-                outfile = io.open(args.outfile, 'w', encoding='utf-8')
+    with io.open(args.base, 'r', encoding='utf-8') as base, \
+            io.open(args.latest, 'r', encoding='utf-8') as latest:
 
-            with outfile:
-                for line in lines:
-                    print(line, file=outfile)
-        except NotFound as exc:

[Sebastian Noack, 2018/09/21 11:51:20]

Can we even run into this exception since we neither load the input files
through the sources module nor do we render includes.

[rhowell, 2018/09/24 22:05:21]

I guess not. Removed it.

-            sys.exit(exc)
+        lines = render_diff(base, latest)
+        if args.outfile == '-':
+            outfile = io.open(sys.stdout.fileno(), 'w',
+                              closefd=False,
+                              encoding=sys.stdout.encoding or 'utf-8')
+        else:
+            outfile = io.open(args.outfile, 'w', encoding='utf-8')
+
+        with outfile:
+            for line in lines:
+                print(line, file=outfile)