fix: added more unit tests for format date pipe

TRACEFOSS-865

Author: fbedarf

src/app/modules/shared/pipes/format-date.pipe.spec.ts

@@ -19,16 +19,37 @@
  * SPDX-License-Identifier: Apache-2.0
  ********************************************************************************/
 
+import { CalendarDateModel } from '@core/model/calendar-date.model';
 import { screen } from '@testing-library/angular';
 import { renderComponent } from '@tests/test-render.utils';
 import { SharedModule } from '..';
 
 describe('FormatDatePipe', () => {
   it('should format date having the 1970 value for the year', async () => {
-    await renderComponent(`{{ 'unitTest.test01' | formatDate }}`, {
+    const date = new CalendarDateModel(null);
+    await renderComponent(`{{ date | formatDate }}`, {
       imports: [SharedModule],
+      componentProperties: { date },
     });
 
-    expect(screen.getByText('This is for unit tests purposes.')).toBeInTheDocument();
+    expect(screen.getByText('--')).toBeInTheDocument();
+  });
+
+  it('should format date without issues', async () => {
+    const date = new CalendarDateModel('2022-02-04T13:48:54Z');
+    await renderComponent(`{{ date | formatDate }}`, {
+      imports: [SharedModule],
+      componentProperties: { date },
+    });
+
+    expect(screen.getByText('2/4/2022')).toBeInTheDocument();
+  });
+
+  it('should return -- if string is empty', async () => {
+    await renderComponent(`{{ '' | formatDate }}`, {
+      imports: [SharedModule],
+    });
+
+    expect(screen.getByText('--')).toBeInTheDocument();
   });
 });

src/app/modules/shared/pipes/format-date.pipe.ts

@@ -48,7 +48,7 @@ export class FormatDatePipe implements PipeTransform, OnDestroy {
 
   public transform(input: string | CalendarDateModel): string {
     if (!input) {
-      return '';
+      return '--';
     }
 
     const date = typeof input === 'string' ? this.transformStringToDate(input) : input.valueOf();