Issue 7094 - Encapsulate management of subscription filters

test/filterStorage_readwrite.js

Index: test/filterStorage_readwrite.js
===================================================================
--- a/test/filterStorage_readwrite.js
+++ b/test/filterStorage_readwrite.js
@@ -103,17 +103,17 @@
   {
     test.ok(filterStorage.initialized, "Initialize after the first load");
     test.equal(filterStorage.fileProperties.version, filterStorage.formatVersion, "File format version");
 
     if (withExternal)
     {
       {
         let subscription = new ExternalSubscription("~external~external subscription ID", "External subscription");
-        subscription.filters = [Filter.fromText("foo"), Filter.fromText("bar")];
+        subscription.filters = ["foo", "bar"];
         filterStorage.addSubscription(subscription);
       }
 
       let externalSubscriptions = [...filterStorage.subscriptions()].filter(subscription => subscription instanceof ExternalSubscription);
       test.equal(externalSubscriptions.length, 1, "Number of external subscriptions after updateExternalSubscription");
 
       test.equal(externalSubscriptions[0].url, "~external~external subscription ID", "ID of external subscription");
       test.equal(externalSubscriptions[0].filters.length, 2, "Number of filters in external subscription");