test: add unit tests for ContentHeroComponent and handle ResizeObserver unavailability

Entire-Checkpoint: c6e522b4276c

libs/ui/components/src/lib/content-hero/content-hero.component.spec.ts

@@ -0,0 +1,41 @@
+import { ComponentFixture, TestBed } from '@angular/core/testing';
+import { TranslateModule } from '@ngx-translate/core';
+import { ContentHeroComponent } from './content-hero.component';
+
+describe('ContentHeroComponent', () => {
+    let fixture: ComponentFixture<ContentHeroComponent>;
+    const originalResizeObserver = globalThis.ResizeObserver;
+
+    afterEach(() => {
+        Object.defineProperty(globalThis, 'ResizeObserver', {
+            configurable: true,
+            writable: true,
+            value: originalResizeObserver,
+        });
+    });
+
+    beforeEach(async () => {
+        await TestBed.configureTestingModule({
+            imports: [ContentHeroComponent, TranslateModule.forRoot()],
+        }).compileComponents();
+
+        fixture = TestBed.createComponent(ContentHeroComponent);
+    });
+
+    it('renders description content when ResizeObserver is unavailable', () => {
+        Object.defineProperty(globalThis, 'ResizeObserver', {
+            configurable: true,
+            writable: true,
+            value: undefined,
+        });
+
+        fixture.componentRef.setInput('title', 'Fallback_Title');
+        fixture.componentRef.setInput('description', 'Plain description');
+
+        expect(() => fixture.detectChanges()).not.toThrow();
+
+        const host = fixture.nativeElement as HTMLElement;
+        expect(host.textContent).toContain('Fallback Title');
+        expect(host.textContent).toContain('Plain description');
+    });
+});

libs/ui/components/src/lib/content-hero/content-hero.component.ts

@@ -110,6 +110,10 @@ export class ContentHeroComponent {
 
     private observeOverflow(el: HTMLElement): void {
         this.resizeObserver?.disconnect();
+        if (typeof ResizeObserver === 'undefined') {
+            this.measureOverflow(el);
+            return;
+        }
         this.resizeObserver = new ResizeObserver(() => this.measureOverflow(el));
         this.resizeObserver.observe(el);
     }