DEV: do not wait for closed composer event on test (#7221)

app/assets/javascripts/discourse/components/composer-editor.js.es6

@@ -916,7 +916,10 @@ export default Ember.Component.extend({
     Ember.run.next(() => {
       $("#main-outlet").css("padding-bottom", 0);
       // need to wait a bit for the "slide down" transition of the composer
-      Ember.run.later(() => this.appEvents.trigger("composer:closed"), 400);
+      Ember.run.later(
+        () => this.appEvents.trigger("composer:closed"),
+        Ember.testing ? 0 : 400
+      );
     });
 
     if (this._enableAdvancedEditorPreviewSync())