code improvements

src/app/img-magnifier/img-magnifier.component.spec.ts

@@ -1,39 +1,5 @@
-// import { async, ComponentFixture, TestBed } from '@angular/core/testing';
-//
-// import { ImgMagnifierComponent } from './img-magnifier.component';
-//
-// // TODO
-//
-// let windowServiceSpy: jasmine.SpyObj<Window>;
-//
-// describe('ImgMagnifierComponent', () => {
-//   let component: ImgMagnifierComponent;
-//   let fixture: ComponentFixture<ImgMagnifierComponent>;
-//
-//   beforeEach(async(() => {
-//     const windowSpy = jasmine.createSpyObj('Window', ['pageXOffset', 'pageYOffset']);
-//
-//     TestBed.configureTestingModule({
-//       declarations: [ ImgMagnifierComponent ],
-//       imports: [
-//       ],
-//       providers: [
-//         {provide: Window, useValue: windowSpy}
-//       ]
-//     })
-//     .compileComponents();
-//
-//     windowServiceSpy = TestBed.inject(Window) as jasmine.SpyObj<Window>;
-//   }));
-//
-//   beforeEach(() => {
-//     fixture = TestBed.createComponent(ImgMagnifierComponent);
-//     component = fixture.componentInstance;
-//     component.ngOnInit();
-//     fixture.detectChanges();
-//   });
-//
-//   it('should create', () => {
-//     expect(component).toBeTruthy();
-//   });
-// });
+import { async, ComponentFixture, TestBed } from '@angular/core/testing';
+
+describe('ImgMagnifierComponent', () => {
+
+});

src/app/img-magnifier/img-magnifier.component.ts

@@ -7,13 +7,13 @@ import {AfterViewInit, Component, ElementRef, Input, OnInit, ViewChild} from '@a
 })
 export class ImgMagnifierComponent implements OnInit, AfterViewInit {
 
-  @Input() src: string;
-  @Input() zoom: number;
-  @Input() magnifierSize: {width: number, height: number};
+  @Input() src: string;   // image source
+  @Input() zoom: number;  // zoom level
+  @Input() magnifierSize: {width: number, height: number};  // size of the magnifier
   @ViewChild('mainImg') mainImg: ElementRef;
 
   backgroundSize;
-  magnifierPos = {x: 0, y: 0};
+  magnifierPos = {x: 0, y: 0};  // position of the magnifier
   showMagnifier = false;
 
   constructor(
@@ -29,7 +29,7 @@ export class ImgMagnifierComponent implements OnInit, AfterViewInit {
     }, 1);
   }
 
-  calcPos(event) {
+  calcPos(event) {  // calculate the current magnifier position
     const img = this.mainImg.nativeElement.getBoundingClientRect();
     this.magnifierPos.x = Math.min(
       img.width - this.magnifierSize.width,
@@ -42,7 +42,7 @@ export class ImgMagnifierComponent implements OnInit, AfterViewInit {
   }
 
   calcBackgroundSize() {
-    this.backgroundSize = this.mainImg ? (this.mainImg.nativeElement.width * this.zoom - this.magnifierSize.width) + 'px ' +
-      (this.mainImg.nativeElement.height * this.zoom - this.magnifierSize.height) + 'px ' : '0 0';
+    this.backgroundSize = this.mainImg ? (this.mainImg.nativeElement.width * this.zoom - this.magnifierSize.width) +
+      'px ' + (this.mainImg.nativeElement.height * this.zoom - this.magnifierSize.height) + 'px ' : '0 0';
   }
 }