Issue 6538, 6781 - Implement script parsing for snippets

lib/snippets.js

 /*
  * 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
@@ skipping 57 matching lines @@
     for (let text of filters)
     {
       let filter = Filter.fromText(text);
       if (filter.isActiveOnDomain(domain) &&
           !ElemHide.getException(filter, domain))
       {
         result.push(filter);
       }
     }
     return result;
+  },
+
+  /**
+   * Parses a script and returns a list of all its commands and their arguments
+   * @param {string} script
+   * @return {Array.<string[]>}

[Manish Jethani, 2018/04/26 13:25:17]

I had to use Array.<string[]> instead of string[][] because ESLint complained
(even though it is valid JSDoc and actually better, oh I hate ESLint).

+   */
+  parseScript(script)
+  {
+    let tree = [];
+
+    let escape = false;
+    let literal = false;
+
+    let call = [];
+    let argument = "";
+
+    for (let character of [...script.trim(), ";"])

[Manish Jethani, 2018/04/26 13:25:17]

The parsing here is as per the specification in Trac #6538. Also see unit tests.

+    {
+      if (escape)
+      {
+        escape = false;
+
+        argument += character;
+      }
+      else if (character == "\\")
+      {
+        escape = true;
+      }
+      else if (character == "'")
+      {
+        literal = !literal;
+      }
+      else if (literal || character != ";" && !/\s/u.test(character))
+      {
+        argument += character;
+      }
+      else
+      {
+        if (argument)
+        {
+          call.push(argument);
+          argument = "";
+        }
+
+        if (character == ";" && call.length > 0)
+        {
+          tree.push(call);
+          call = [];
+        }
+      }
+    }
+
+    return tree;
   }
 };
 
 exports.Snippets = Snippets;