fix(image loader): clear src and srct on changes and pre load image

prevents rendered image being reused when inputs change

Author: jackhkmatthews

src/app/image-loader/image-loader/image-loader.component.spec.ts

@@ -218,4 +218,10 @@ describe('ImageLoaderComponent', () => {
     component.ngOnChanges();
     expect(spy).toHaveBeenCalled();
   });
+
+  it('should preload image on changes', () => {
+    const spy = spyOn(component, 'preloadImage');
+    component.ngOnChanges();
+    expect(spy).toHaveBeenCalled();
+  });
 });

src/app/image-loader/image-loader/image-loader.component.ts

@@ -340,6 +340,9 @@ export class ImageLoaderComponent implements OnInit, AfterViewInit, OnDestroy, O
    * @memberof ImageLoaderComponent
    */
   public ngOnChanges(): void {
+    this.src = '';
+    this.srcset = '';
     this.setPlaceholder();
+    this.preloadImage();
   }
 }