Layer undefined when viewing app in Firefox

[FranklinAlexander]

I know that when viewing my app in Firefox browser, the query widget loads before the layer, which causes the layer to be undefined. To deal with this I set a timeout in my function (_getSelectedLayerInformation) within a Promise, which works and returns the correct info. The problem is that in the function is called I am not getting back anything. 

_getSelectedLayerInfomation: function(){
      var map = this.map;
      var type = 0;//0 means doesn't select any layer
      var layerItem = "FRRP_Subregions";
      var glayerIds = map.graphicsLayerIds;
      var items = this.layerChooserFromMapWithDropbox.getSelectedItems();
      if(items.length > 0){
          console.log("layer items length ", items.length);
          layerItem = "FRRP_Subregions";
      }
      return new Promise (function(resolve, reject) {
          setTimeout(function() {
              var layer = map.getLayer("FRRP_Subregions");
              console.log("sub-regions ", layer);
              if(layer){
                console.log("layer ", layer);
                //var layerInfo = layerItem.layerInfo;
                //layer = layerInfo.layerObject;
                if(layer.url){
                  console.log("layer url ", layer.url);
                  if(glayerIds.indexOf(layer.id) >= 0){
                    //layer exist in map
                    type = 1;
                  }else{
                    //layer exist in MapService
                    type = 2;
                  }
                }else{
                  //feature collection
                  type = 3;
                }
              }
              console.log(type, layerItem, layer);
              return {
                type: type,
                layerItem: layerItem,
                layer: layer
             };
         }, 500);
      })
},‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

The above function gets called inside of this function, but returns nothing. I can't figure out how to set up a promise that actually works that will execute the _getSelectedLayerInformation function and then execute the rest of the code. 

_featureSetChooser: function() {
        this.featureSetChooserForSingleLayer = null;
        let info = this._getSelectedLayerInfomation();  
        info.then(console.log("layer info ", info));  //// returns Promise pending???
   
        if(type > 0){
          this.featureSetChooserForSingleLayer = new FeatureSetChooserForSingleLayer({
            map: this.map,
            featureLayer: info.layer,
            updateSelection: false
          });

          this._selectionHandle = on(info.layer, 'selection-complete', lang.hitch(this, function() {
            var oldUseSelectedChecked = this.selectionRadio.getStatus() && this.selectionRadio.getValue();
            this._updateSelectedFeaturesCount();
            if(oldUseSelectedChecked){
              this._updateBuffer();
            }
          }));

          this.own(on(this.featureSetChooserForSingleLayer, 'user-clear', lang.hitch(this, this._onUserClear)));
          this.own(on(this.featureSetChooserForSingleLayer, 'loading', lang.hitch(this, lang.hitch(this, function(){
            this._clearBufferLayer();
            this._onLoading();
          }))));
          this.own(on(this.featureSetChooserForSingleLayer, 'unloading', lang.hitch(this, lang.hitch(this, function(){
            this._onUnloading();
            this._updateBuffer();
          }))));
          this.featureSetChooserForSingleLayer.placeAt(this.featureSetChooserDiv);
          //uncheck "Use selected features" option when begin drawing
          this.own(on(this.featureSetChooserForSingleLayer, 'draw-activate', lang.hitch(this, function(){
            this.uncheckSelectedFeaturesRadio();
          })));
        }
        var draw = query(".jimu-single-layer-featureset-chooser", this.domNode)[0];
        console.log("drawbox ", draw);
},‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

In the above function, the log statement on line 4 returns a pending promise. I am still trying how to implement promises, so I think I am leaving something out, but just can't figure out what that is! Thanks ahead of time for any pointers!