Add a window check, and test for it

Author: RVMendoza

angular/projects/spark-angular/src/lib/utilities/isElementVisible/isElementVisible.spec.ts

@@ -23,6 +23,7 @@ class Test1Component {
 describe('isElementVisible', () => {
   let component: Test1Component;
   let componentFixture: ComponentFixture<Test1Component>;
+  let windowSpy;
 
   beforeEach(async(() => {
     TestBed.configureTestingModule({
@@ -31,11 +32,16 @@ describe('isElementVisible', () => {
   }));
 
   beforeEach(() => {
+    windowSpy = jest.spyOn(window, 'window', 'get');
     componentFixture = TestBed.createComponent(Test1Component);
     component = componentFixture.componentInstance;
     componentFixture.detectChanges();
   });
 
+  afterEach(() => {
+    windowSpy.mockRestore();
+  });
+
   it('should return false for element with display: none', () => {
     expect(isElementVisible(component.elDisplayNone)).toEqual(false);
   });
@@ -51,4 +57,10 @@ describe('isElementVisible', () => {
   it('should return true for element with visibility: visible', () => {
     expect(isElementVisible(component.elVisibilityVisible)).toEqual(true);
   });
+
+  it('should not use window scope if window is undefined', () => {
+    windowSpy.mockImplementation(() => undefined);
+    expect(window).toBeUndefined();
+    expect(isElementVisible(component.elDisplayNone)).toEqual(undefined);
+  });
 });

angular/projects/spark-angular/src/lib/utilities/isElementVisible/isElementVisible.ts

@@ -10,13 +10,15 @@ export const isElementVisible = (elRef: ElementRef): boolean => {
   if (!elRef) {
     return;
   }
-  const elementDisplayValue = window.getComputedStyle(elRef.nativeElement)
-    .display;
-  const elementVisibilityValue = window.getComputedStyle(elRef.nativeElement)
-    .visibility;
-  const elementIsVisible =
-    elementDisplayValue === 'none' || elementVisibilityValue === 'hidden'
-      ? false
-      : true;
-  return elementIsVisible;
+  if (typeof window !== 'undefined') {
+    const elementDisplayValue = window.getComputedStyle(elRef.nativeElement)
+      .display;
+    const elementVisibilityValue = window.getComputedStyle(elRef.nativeElement)
+      .visibility;
+    const elementIsVisible =
+      elementDisplayValue === 'none' || elementVisibilityValue === 'hidden'
+        ? false
+        : true;
+    return elementIsVisible;
+  }
 };