Issue 6727 - Use string rather than map for single-domain filters

test/filterClasses.js

Index: test/filterClasses.js
===================================================================
--- a/test/filterClasses.js
+++ b/test/filterClasses.js
@@ -66,20 +66,27 @@
   {
     result.push("disabled=" + filter.disabled);
     result.push("lastHit=" + filter.lastHit);
     result.push("hitCount=" + filter.hitCount);
 
     let domains = [];
     if (filter.domains)
     {
-      for (let [domain, isIncluded] of filter.domains)
+      if (typeof filter.domains == "string")
+      {
+        domains.push(filter.domains);
+      }
+      else
       {
-        if (domain != "")
-          domains.push(isIncluded ? domain : "~" + domain);
+        for (let [domain, isIncluded] of filter.domains)
+        {
+          if (domain != "")
+            domains.push(isIncluded ? domain : "~" + domain);
+        }
       }
     }
     result.push("domains=" + domains.sort().join("|"));
 
     if (filter instanceof RegExpFilter)
     {
       result.push("regexp=" + filter.regexp.source);
       result.push("contentType=" + filter.contentType);
@@ -103,18 +110,20 @@
     {
       if (filter instanceof ElemHideFilter)
         result.push("type=elemhide");
       else if (filter instanceof ElemHideException)
         result.push("type=elemhideexception");
       else if (filter instanceof ElemHideEmulationFilter)
         result.push("type=elemhideemulation");
 
+      let domains = typeof filter.domains == "string" ?
+                      [[filter.domains, true]] : filter.domains;
       result.push("selectorDomains=" +
-                  [...filter.domains || []]
+                  [...domains || []]
                   .filter(([domain, isIncluded]) => isIncluded)
                   .map(([domain]) => domain.toLowerCase()));
       result.push("selector=" + filter.selector);
     }
   }
   return result;
 }