Issue 7059 - Modify fldiff so it can handle multiple files

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
 import io
 import sys
+import os
 
 from .renderer import render_diff
+from .parser import parse_filterlist
 
 __all__ = ['main']
 
 
-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()
+class MissingFilterListError(Exception):
+    """Error in finding a latest filter list, or base filter lists."""
 
 
-def main():
+def _get_version(filterlist, base):

[Vasily Kuznetsov, 2018/10/29 23:47:33]

Nit: maybe this argument can just be called "filename" here, since this is what
it means basically.

[rhowell, 2018/10/31 00:20:58]

Done.

+    for line in parse_filterlist(filterlist):
+        if line.type == 'metadata' and line.key == 'Version':
+            return line.value
+    raise MissingFilterListError('Unable to find Version in {}'.format(base))
+
+
+def parse_args(args_in=None):
+    parser = argparse.ArgumentParser(description='Render a filter list diff.')
+    parser.add_argument('latest',
+                        help='The most recent version of the filter list')
+    parser.add_argument('-o', '--output_dir', default=os.getcwd(),
+                        help='The directory to write the diffs to')
+    parser.add_argument('base_files', nargs='+',
+                        help='One or more archived filter lists')
+    return parser.parse_args(args_in)
+
+
+def main(args_in=None):
     """Entry point for the diff rendering script (fldiff)."""
-    args = parse_args()
+    arg = parse_args(args_in)
 
-    with io.open(args.base, 'r', encoding='utf-8') as base, \
-            io.open(args.latest, 'r', encoding='utf-8') as latest:
+    with io.open(arg.latest, 'r', encoding='utf8') as latest_list:
+        latest = latest_list.readlines()
+
+    for base_file in arg.base_files:
+        with io.open(base_file, 'r', encoding='utf8') as base_file:
+            base = base_file.readlines()
 
         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')
+        try:
+            version = _get_version(base, base_file.name)
+        except MissingFilterListError as exc:
+            sys.exit(exc)
 
-        with outfile:
+        # TODO: After removing the dict test, this .strip() can go
+        outfile = os.path.join(arg.output_dir.strip(),
+                               'diff{}.txt'.format(version))
+
+        with io.open(outfile, 'w', encoding='utf-8') as out_fp:
             for line in lines:
-                print(line, file=outfile)
+                out_fp.write(line + '\n')