small fix for test

Author: andrefarzat

src/app/shared/plotly.service.spec.ts

@@ -12,6 +12,16 @@ describe('PlotlyService', () => {
         });
     });
 
+    it('should get a plotly instance by id', inject([PlotlyService], (service: PlotlyService) => {
+        const instance = { id: 'aidi' } as Plotly.PlotlyHTMLElement;
+
+        PlotlyService.insert(instance);
+        expect(service.getInstanceByDivId('aidi')).toBe(instance);
+
+        PlotlyService.remove(instance);
+        expect(service.getInstanceByDivId('aidi')).toBeUndefined();
+    }));
+
     it('should check the plotly dependency', inject([PlotlyService], (service: PlotlyService) => {
         PlotlyService.setPlotly(undefined);
         expect(() => service.getPlotly()).toThrowError(`Peer dependency plotly.js isn't installed`);
@@ -64,15 +74,4 @@ describe('PlotlyService', () => {
         service.resize('one' as any);
         expect(plotly.Plots.resize).toHaveBeenCalledWith('one');
     }));
-
-
-    it('should get a plotly instance by id', inject([PlotlyService], (service: PlotlyService) => {
-        const instance = { id: 'aidi' } as Plotly.PlotlyHTMLElement;
-
-        PlotlyService.insert(instance);
-        expect(service.getInstanceByDivId('aidi')).toBe(instance);
-
-        PlotlyService.remove(instance);
-        expect(service.getInstanceByDivId('aidi')).toBeUndefined();
-    }));
 });

src/app/shared/plotly.service.ts

@@ -30,7 +30,7 @@ export class PlotlyService {
 
     public getInstanceByDivId(id: string): Plotly.PlotlyHTMLElement | undefined {
         for (const instance of PlotlyService.instances) {
-            if (instance.id === id) {
+            if (instance && instance.id === id) {
                 return instance;
             }
         }