Issue 2658 - Got rid of try..catch for filter validation

lib/filterValidation.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 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
@@ skipping 22 matching lines @@
   }
   catch (e)
   {
     return false;
   }
   return true;
 }
 
 /**
  * @typedef ParsedFilter
- * @property {?Filter} [filter]  The parsed filter is it is valid. Or null if

[kzar, 2015/06/08 11:28:04]

Nit: Typo "The parsed filter_if_ it is valid"

[Sebastian Noack, 2015/06/08 12:00:08]

Done.

+ * @property {?Filter} [filter]  The parsed filter if it is valid. Or null if
  *                               the given string is empty or a filter list header.
  * @property {string} [error]    An error message indicated that the filter cannot
  *                               be parsed or contains an invalid CSS selector.
  */
 
 let parseFilter =
 /**
  * Parses and validates a filter given by the user.
  *
  * @param {string}  text
- * @param {Boolean} [ignoreHeaders=false]  If true, no error is produced
- *                                         for filter list headers, instead
- *                                         {filter: null} is returned.
+ * @param {Boolean} [ignoreHeaders=false]  If true, {filter: null} is
+                                           returned instead an error
+                                           for filter list headers.
  * @return {ParsedFilter}
  */
 exports.parseFilter = function(text, ignoreHeaders)
 {
   let filter = null;
   text = Filter.normalize(text);
 
   if (text)
   {
     if (text[0] != "[")
@@ skipping 21 matching lines @@
  * @property {string} [error]      An error message indicated that any filter cannot
  *                                 be parsed or contains an invalid CSS selector.
  */
 
 /**
  * Parses and validates a newline-separated list of filters given by the user.
  *
  * @param {string}  text
  * @param {Boolean} [ignoreHeaders=false]  If true, filter list headers
  *                                         will be stripped instead of
- *                                         producing an error.

[kzar, 2015/06/08 11:28:04]

Nit: "returning"?

[Sebastian Noack, 2015/06/08 12:00:08]

I did not say to "return" an error, because strictly speaking we return an
object containing an error. But fair enough.

+ *                                         returning an error.
  * @return {ParsedFilters}
  */
 exports.parseFilters = function(text, ignoreHeaders)
 {
   let lines = text.split("\n");
   let filters = [];
 
   for (let i = 0; i < lines.length; i++)
   {
     let {filter, error} = parseFilter(lines[i], ignoreHeaders);
 
     if (error)
       return {error: ext.i18n.getMessage("line", (i + 1).toString()) + ": " + error};
 
     if (filter)

[kzar, 2015/06/08 11:28:04]

Nit: Should be `else if (filter)` IMO

[Sebastian Noack, 2015/06/08 12:00:08]

No, it shouldn't. The else would be redundant, as we return above.

       filters.push(filter);
   }
 
   return {filters: filters};
 };