Reactivate tests for the ScrollPagePipe

projects/common/pipes/scroll-pages.pipe.spec.ts

+import { TestBed } from '@angular/core/testing';
+import { SharedModule } from 'common/shared.module';
+import { Page } from 'common/models/page';
 import { ScrollPagesPipe } from './scroll-pages.pipe';
 
 describe('ScrollPagesPipe', () => {
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [
+        SharedModule
+      ]
+    })
+      .compileComponents();
+  });
+
+  const page: Page = new Page({
+    hasMaxWidth: false,
+    maxWidth: 0,
+    margin: 0,
+    backgroundColor: 'white',
+    alwaysVisible: false,
+    alwaysVisiblePagePosition: 'left',
+    alwaysVisibleAspectRatio: 50,
+    sections: []
+  });
+
+  const pipe = new ScrollPagesPipe();
+
   it('create an instance', () => {
-    const pipe = new ScrollPagesPipe();
     expect(pipe).toBeTruthy();
   });
+
+  it('should transform 3 pages to 2 scroll pages', () => {
+    const pages = [page, page, { ...page, alwaysVisible: true } as Page];
+    expect(pipe.transform(pages).length).toBe(2);
+  });
+
+  it('should transform 2 pages to 2 scroll pages', () => {
+    const pages = [page, page];
+    expect(pipe.transform(pages).length).toBe(2);
+  });
 });