Issue 6538, 6781 - Implement support for snippet filters

lib/snippets.js

Index: lib/snippets.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/snippets.js
@@ -0,0 +1,81 @@
+/*
+ * 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/>.
+ */
+
+"use strict";
+
+/**
+ * @fileOverview Snippets implementation.
+ */
+
+const {ElemHide} = require("./elemHide");
+const {Filter} = require("./filterClasses");
+
+let filters = new Set();
+
+/**
+ * Container for snippet filters
+ * @class
+ */
+let Snippets = {
+  /**
+   * Removes all known filters
+   */
+  clear()
+  {
+    filters.clear();
+  },
+
+  /**
+   * Add a new snippet filter
+   * @param {SnippetFilter} filter
+   */
+  add(filter)
+  {
+    filters.add(filter.text);
+  },
+
+  /**
+   * Removes a snippet filter
+   * @param {SnippetFilter} filter
+   */
+  remove(filter)
+  {
+    filters.delete(filter.text);
+  },
+
+  /**
+   * Returns a list of all scripts active on a particular domain
+   * @param {string} domain
+   * @return {string[]}
+   */
+  getScriptsForDomain(domain)
+  {
+    let result = [];
+    for (let text of filters)
+    {
+      let filter = Filter.fromText(text);
+      if (filter.isActiveOnDomain(domain) &&
+          !ElemHide.getException(filter, domain))
+      {
+        result.push(filter.code);
+      }
+    }
+    return result;
+  }
+};
+
+exports.Snippets = Snippets;