Small Changes

public/service-worker.js

@@ -52,13 +52,21 @@ self.addEventListener('fetch', function(event){
                 .error(function(error){
                   console.log(error);  
                 });
+            }else if(event.request.url.indexOf("/last-modified") > -1){
+                var myHeaders = new Headers();
+                myHeaders.append('test', 'test');
+                var init = {
+                    method: 'GET',
+                    headers: myHeaders,
+                    cache: 'default'
+                }
+                
+                return fetch(event.request.url, init);
             }else{
                 return fetch(event.request)
                 .then(function(response){
                     return caches.open(CACHE_NAME).then(function(cache){
-                        if(event.request.url.indexOf("tile_cache") < 0){
-                            cache.put(event.request.url, response.clone());
-                        }
+                        cache.put(event.request.url, response.clone());
                         return response;
                     });  
                 });

routes/web.php

 <?php
 
+use Illuminate\Http\Request;
+
 /*
 |--------------------------------------------------------------------------
 | Web Routes
@@ -15,9 +17,16 @@ Route::get('/', function () {
 
 });
 
-Route::get('/last-modified', function(){
-    return Response::make("", 200)
-        ->header("last-modified", filemtime(base_path()) * 1000);
+Route::get('/last-modified', function(Request $request){
+    die(var_dump($request->header()));
+    $file = public_path() . mix('/js/modules.js');
+    if(strpos($file, "?") != FALSE)
+        $file = substr($file, 0, strpos($file, "?"));
+
+    $response = Response::make("", 200)
+        ->header("last-modified", filemtime($file) * 1000);
+
+    return $response;
 });
 
 Route::group(['prefix' => 'download'], function(){