Cover the one behavioural change of #1300 with a real spec

clarin-description-item-field is the only component this port changes
behaviourally: it used to join every description value into a single innerHTML
with <br>, and now renders one <div> per value so each can carry its own lang.

That component had no spec on dtq-dev-9-base. dtq-dev has one, but it is a bare
"should create" smoke test that would not have caught any of this, and the
source commit did not touch it.

Adds five cases against the new shape: one element per value, per-value BCP 47
lang, no lang attribute for the wildcard language, makeLinks still producing
anchors through [innerHTML], and the empty-metadata case.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: milanmajchrak

src/app/item-page/simple/field-components/clarin-description-item-field/clarin-description-item-field.component.spec.ts

@@ -0,0 +1,87 @@
+import {
+  ComponentFixture,
+  TestBed,
+} from '@angular/core/testing';
+import { By } from '@angular/platform-browser';
+
+import { Item } from '../../../../core/shared/item.model';
+import { ClarinDescriptionItemFieldComponent } from './clarin-description-item-field.component';
+
+describe('ClarinDescriptionItemFieldComponent', () => {
+
+  let component: ClarinDescriptionItemFieldComponent;
+  let fixture: ComponentFixture<ClarinDescriptionItemFieldComponent>;
+
+  function itemWithDescriptions(values: { value: string, language: string }[]): Item {
+    return Object.assign(new Item(), {
+      metadata: {
+        'dc.description': values,
+      },
+    });
+  }
+
+  function render(item: Item): void {
+    fixture = TestBed.createComponent(ClarinDescriptionItemFieldComponent);
+    component = fixture.componentInstance;
+    component.fields = ['dc.description'];
+    component.item = item;
+    fixture.detectChanges();
+  }
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [ClarinDescriptionItemFieldComponent],
+    }).compileComponents();
+  });
+
+  it('should render one element per description value', () => {
+    render(itemWithDescriptions([
+      { value: 'first description', language: 'en_US' },
+      { value: 'second description', language: 'cs_CZ' },
+    ]));
+
+    const divs = fixture.debugElement.queryAll(By.css('div'));
+    expect(divs.length).toBe(2);
+    expect(divs[0].nativeElement.textContent).toContain('first description');
+    expect(divs[1].nativeElement.textContent).toContain('second description');
+  });
+
+  it('should give each value its own normalized BCP 47 lang attribute', () => {
+    render(itemWithDescriptions([
+      { value: 'anglicky', language: 'en_US' },
+      { value: 'cesky', language: 'cs_CZ' },
+    ]));
+
+    const divs = fixture.debugElement.queryAll(By.css('div'));
+    expect(divs[0].nativeElement.getAttribute('lang')).toEqual('en-US');
+    expect(divs[1].nativeElement.getAttribute('lang')).toEqual('cs-CZ');
+    expect(fixture.nativeElement.innerHTML).not.toContain('lang="en_US"');
+  });
+
+  it('should omit the lang attribute for the wildcard language', () => {
+    render(itemWithDescriptions([{ value: 'language independent', language: '*' }]));
+
+    const div = fixture.debugElement.query(By.css('div'));
+    expect(div.nativeElement.hasAttribute('lang')).toBeFalse();
+    expect(fixture.nativeElement.innerHTML).not.toContain('lang="*"');
+  });
+
+  it('should still turn URLs in the description into links', () => {
+    render(itemWithDescriptions([
+      { value: 'see https://lindat.cz for more', language: 'en_US' },
+    ]));
+
+    const anchor = fixture.debugElement.query(By.css('div a'));
+    expect(anchor).toBeTruthy();
+    expect(anchor.nativeElement.getAttribute('href')).toEqual('https://lindat.cz');
+    expect(anchor.nativeElement.getAttribute('target')).toEqual('_blank');
+  });
+
+  it('should render nothing when the item has no description', () => {
+    render(Object.assign(new Item(), { metadata: {} }));
+
+    expect(component.descriptionEntries).toEqual([]);
+    expect(fixture.debugElement.queryAll(By.css('div')).length).toBe(0);
+  });
+
+});