[DSC-1484] feature: added utility functions

Author: vNovski

src/app/core/cache/builders/link.service.spec.ts

@@ -251,4 +251,55 @@ describe('LinkService', () => {
     });
   });
 
+  describe('User Functions', () => {
+    fdescribe('isLinkInternal', () => {
+      it('should return true for internal link starting with "/"', () => {
+        result = service.isLinkInternal('/my-link', 'https://currentdomain');
+        expect(result).toBe(true);
+      });
+
+      it('should return true for internal link starting with currentURL', () => {
+        result = service.isLinkInternal('https://currentdomain/my-link', 'https://currentdomain');
+        expect(result).toBe(true);
+      });
+
+      it('should return true for internal link starting with "currentdomain"', () => {
+        result = service.isLinkInternal('currentdomain/my-link', 'https://currentdomain');
+        expect(result).toBe(true);
+      });
+
+      it('should return false for external link', () => {
+        result = service.isLinkInternal('https://externaldomain/my-link', 'https://currentdomain');
+        expect(result).toBe(false);
+      });
+
+      it('should return true for internal link link without leading "/"', () => {
+        result = service.isLinkInternal('my-link', 'https://currentdomain');
+        expect(result).toBe(true);
+      });
+    });
+
+    fdescribe('transformInternalLink', () => {
+      it('should transform internal link by removing currentURL', () => {
+        result = service.transformInternalLink('https://currentdomain/my-link', 'https://currentdomain');
+        expect(result).toBe('/my-link');
+      });
+
+      it('should transform internal link by adding leading "/" if missing', () => {
+        result = service.transformInternalLink('currentdomain/my-link', 'https://currentdomain');
+        expect(result).toBe('/my-link');
+      });
+
+      it('should return unchanged link for external link', () => {
+        result = service.transformInternalLink('https://externalDomain/my-link', 'https://currentdomain');
+        expect(result).toBe('https://externalDomain/my-link');
+      });
+
+      it('should return unchanged link for internal link with leading "/"', () => {
+        result = service.transformInternalLink('/my-link', 'https://currentdomain');
+        expect(result).toBe('/my-link');
+      });
+    });
+  });
+
 });

src/app/core/cache/builders/link.service.ts

@@ -123,4 +123,47 @@ export class LinkService {
     return result;
   }
 
+  /**
+   * Check if the provided link is internal, i.e., it starts with a '/' or matches the current URL.
+   *
+   * @param link The link to be checked.
+   * @param currentURL The current URL to compare against.
+   * @returns A boolean indicating whether the link is internal.
+   */
+  public isLinkInternal(link: string, currentURL: string): boolean {
+    // Create a Domain object for the provided link
+    const currentDomain = new URL(currentURL).hostname;
+
+    return link.startsWith('/')
+      || link.startsWith(currentURL)
+      || link.startsWith(currentDomain)
+      || link === currentDomain
+      || !link.includes('://');
+  }
+
+  /**
+   * Transform an internal link based on the current URL.
+   *
+   * @param link The link to be transformed.
+   * @param currentURL The current URL used for transformation.
+   * @returns The transformed internal link.
+   */
+  public transformInternalLink(link: string, currentURL: string): string {
+    // Create a Domain object for the provided link
+    const currentDomain = new URL(currentURL).hostname;
+
+    if (link.startsWith(currentURL)) {
+      const currentSegments = link.substring(currentURL.length);
+      return currentSegments.startsWith('/') ? currentSegments : `/${currentSegments}`;
+    }
+
+    if (link.startsWith(currentDomain)) {
+      const currentSegments = link.substring(currentDomain.length);
+      return currentSegments.startsWith('/') ? currentSegments : `/${currentSegments}`;
+    }
+
+    return link;
+
+  }
+
 }