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
@@ skipping 10 matching lines @@
 import io
 import sys
 import os
 
 from .renderer import render_diff
 from .parser import parse_filterlist
 
 __all__ = ['main']
 
 
-class MissingFilterListError(Exception):
-    """Error in finding a latest filter list, or base filter lists."""
+class MissingVersionError(Exception):
+    """Unable to find Version in filter list."""
 
 
-def _get_version(filterlist):
+def _get_version(filterlist, filename):
     for line in parse_filterlist(filterlist):
-        if line.type == 'header':
-            base = line.version
         if line.type == 'metadata' and line.key == 'Version':
             return line.value
-    raise MissingFilterListError('Unable to find Version in [{}]'.format(base))

[Vasily Kuznetsov, 2018/10/29 16:31:48]

Wouldn't it be more helpful to give filename in this error message instead of
the version from the header? What do you think?

[rhowell, 2018/10/29 20:01:40]

Yeah. With this (old) method, it returns the header line:

    Unable to find Version in [Adblock Plus 2.0]

But it does seem more accurate and explicit to return the file's name:

    Unable to find Version in
/tmp/pytest-of-emma/pytest-372/test_no_version0/root/archive/list113.txt

+    raise MissingVersionError('Unable to find Version in {}'.format(filename))
 
 
-def parse_args(args_in=None):
+def parse_args():
     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)
+    return parser.parse_args()
 
 
-def main(args_in=None):
+def main():
     """Entry point for the diff rendering script (fldiff)."""
-    arg = parse_args(args_in)
-
-    with io.open(arg.latest, 'r', encoding='utf8') as latest_list:
+    args = parse_args()
+    with io.open(args.latest, 'r', encoding='utf8') as latest_list:
         latest = latest_list.readlines()
 
-    for base_file in arg.base_files:
+    for base_file in args.base_files:
         with io.open(base_file, 'r', encoding='utf8') as base_file:
             base = base_file.readlines()
-            lines = render_diff(base, latest)
-            try:
-                version = _get_version(base)
-            except MissingFilterListError as exc:
-                sys.exit(exc)
 
-            # TODO: After removing the dict test, this .strip() can go
-            outfile = os.path.join(arg.output_dir.strip(),
-                                   'diff{}.txt'.format(version))
+        lines = render_diff(base, latest)
+        try:
+            version = _get_version(base, base_file.name)
+        except MissingVersionError as exc:
+            sys.exit(exc)
 
-            with io.open(outfile, 'w', encoding='utf-8') as out_fp:
-                for line in lines:
-                    out_fp.write(line + '\n')
+        outfile = os.path.join(args.output_dir, 'diff{}.txt'.format(version))
+        with io.open(outfile, 'w', encoding='utf-8') as out_fp:
+            for line in lines:
+                out_fp.write(line + '\n')