Implement blocking functionality after certain count of visits, added tests

lib/db.js

@@ -1,5 +1,5 @@
 var sqlite3 = require('sqlite3').verbose();
-var db = new sqlite3.Database("./proxy.db")
+var db = new sqlite3.Database("./proxy.db");
 
 /** TODO - MAKE THESE FUNCTIONS THEIR OWN MODULE. VVV 
  *  FIXME - need to close the database connection
@@ -35,7 +35,7 @@ function updateVisitCount(hostname) {
  */
 function addHostToTable(hostname) {
     db.serialize(() => {
-        db.run("insert into hosts (hostname, visitcount) values (?, 0)", [hostname])
+        db.run("insert into hosts (hostname, visitcount) values (?, 0)", [hostname]);
     })
 }
 
@@ -43,14 +43,21 @@ function addHostToTable(hostname) {
  * Either initialize a row in the database, or update the visit count for a row.
  * @param {string} hostname Host that was visited
  */
-exports.visitHost = function (hostname) {
+exports.visitHost = function (hostname, callbackFn) {
     return db.serialize(() => {
         db.get("select * from hosts where hostname = ?", [hostname], (err, row) => {
             if (row === undefined) {
                 addHostToTable(hostname);
+                callbackFn(true);
             } else {
-                updateVisitCount(hostname);
+                // Do the blocking, make this configurable.
+                if (row.visitcount >= 2) {
+                    callbackFn(false);
+                } else {
+                    updateVisitCount(hostname);
+                    callbackFn(true);
+                }
             }
-        })
+        });
     });
 }