🐛 Fixed urls being /404/ after starting the Ghost server

no issue

- there was a timing bug in Ghost
- we do operations in parallel on bootstrap
  - 1) we fetch the resources as early as possible
  - 2) we do all the rest (express bootstrapping, theme loading, router registration) etc.
- it can happen that (2) happens too slow and ends in the situation that the queue, which is responsible
  to handle both parallel actions, does not wait for the routers and closes the event
- this is a short term fix
- i need to reconsider if there is a better long term fix

core/server/services/url/Queue.js

@@ -82,6 +82,7 @@ class Queue extends EventEmitter {
         if (!this.queue.hasOwnProperty(options.event)) {
             this.queue[options.event] = {
                 tolerance: options.tolerance,
+                requiredSubscriberCount: options.requiredSubscriberCount || 0,
                 subscribers: []
             };
         }
@@ -136,7 +137,8 @@ class Queue extends EventEmitter {
                 delete this.toNotify[action];
                 debug('ended (1)', event, action);
                 this.emit('ended', event);
-            } else if (this.toNotify[action].timeoutInMS > this.queue[event].tolerance) {
+            } else if (this.queue[options.event].subscribers.length >= this.queue[options.event].requiredSubscriberCount &&
+                this.toNotify[action].timeoutInMS > this.queue[event].tolerance) {
                 delete this.toNotify[action];
                 debug('ended (2)', event, action);
                 this.emit('ended', event);
@@ -159,6 +161,7 @@ class Queue extends EventEmitter {
         if (!this.queue.hasOwnProperty(options.event)) {
             this.queue[options.event] = {
                 tolerance: options.tolerance || 0,
+                requiredSubscriberCount: options.requiredSubscriberCount || 0,
                 subscribers: []
             };
         }

core/server/services/url/Resources.js

@@ -126,7 +126,8 @@ class Resources {
                 // CASE: all resources are fetched, start the queue
                 this.queue.start({
                     event: 'init',
-                    tolerance: 100
+                    tolerance: 100,
+                    requiredSubscriberCount: 1
                 });
             });
     }

core/test/unit/services/url/Queue_spec.js

@@ -241,5 +241,36 @@ describe('Unit: services/url/Queue', function () {
                 timeoutInMS: 20
             });
         });
+
+        it('late subscribers', function (done) {
+            let notified = 0;
+            let called = 0;
+
+            queue.addListener('ended', function (event) {
+                event.should.eql('nachos');
+                notified.should.eql(1);
+                called.should.eql(1);
+                done();
+            });
+
+            setTimeout(function () {
+                queue.register({
+                    event: 'nachos',
+                    tolerance: 100,
+                    timeoutInMS: 20,
+                    requiredSubscriberCount: 1
+                }, function () {
+                    called = called + 1;
+                    notified = notified + 1;
+                });
+            }, 500);
+
+            queue.start({
+                event: 'nachos',
+                tolerance: 60,
+                timeoutInMS: 20,
+                requiredSubscriberCount: 1
+            });
+        });
     });
 });