UFM: Fixes the truncate filter to only add ellipsis when text is actually truncated (closes #20395) (#20396)

* Initial plan

* Fix UFM truncate filter to only add ellipsis when text is actually truncated

Co-authored-by: iOvergaard <752371+iOvergaard@users.noreply.github.com>

* feat: trims string before evaluating

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: iOvergaard <752371+iOvergaard@users.noreply.github.com>

src/Umbraco.Web.UI.Client/src/packages/ufm/filters/truncate.filter.test.ts

@@ -0,0 +1,67 @@
+import { expect } from '@open-wc/testing';
+import { UmbUfmTruncateFilterApi } from './truncate.filter.js';
+
+describe('UmbUfmTruncateFilter', () => {
+	let filter: UmbUfmTruncateFilterApi;
+
+	beforeEach(() => {
+		filter = new UmbUfmTruncateFilterApi();
+	});
+
+	describe('filter', () => {
+		it('should not add ellipsis when text is shorter than length', () => {
+			const result = filter.filter('Test', 10);
+			expect(result).to.equal('Test');
+		});
+
+		it('should not add ellipsis when text equals length', () => {
+			const result = filter.filter('Test', 4);
+			expect(result).to.equal('Test');
+		});
+
+		it('should add ellipsis when text is longer than length', () => {
+			const result = filter.filter('Lorem ipsum', 5);
+			expect(result).to.equal('Lorem…');
+		});
+
+		it('should add custom tail when text is truncated', () => {
+			const result = filter.filter('Lorem ipsum', 5, '...');
+			expect(result).to.equal('Lorem...');
+		});
+
+		it('should not add tail when tail is false and text is truncated', () => {
+			const result = filter.filter('Lorem ipsum', 5, 'false');
+			expect(result).to.equal('Lorem');
+		});
+
+		it('should add ellipsis when tail is true and text is truncated', () => {
+			const result = filter.filter('Lorem ipsum', 5, 'true');
+			expect(result).to.equal('Lorem…');
+		});
+
+		it('should not add ellipsis when tail is false and text is not truncated', () => {
+			const result = filter.filter('Test', 10, 'false');
+			expect(result).to.equal('Test');
+		});
+
+		it('should not add custom tail when text is not truncated', () => {
+			const result = filter.filter('Test', 10, '...');
+			expect(result).to.equal('Test');
+		});
+
+		it('should handle empty string', () => {
+			const result = filter.filter('', 10);
+			expect(result).to.equal('');
+		});
+
+		it('should handle non-string input', () => {
+			const result = filter.filter(null as any, 10);
+			expect(result).to.equal(null);
+		});
+
+		it('should trim whitespace before adding ellipsis', () => {
+			const result = filter.filter('Hello world', 6);
+			expect(result).to.equal('Hello…');
+		});
+	});
+});

src/Umbraco.Web.UI.Client/src/packages/ufm/filters/truncate.filter.ts

@@ -2,13 +2,22 @@ import { UmbUfmFilterBase } from './base.filter.js';
 
 class UmbUfmTruncateFilterApi extends UmbUfmFilterBase {
 	filter(str: string, length: number, tail?: string) {
-		if (typeof str !== 'string' || !str.length) return str;
+		if (typeof str !== 'string') return str;
+
+		// Remove leading/trailing whitespace before calculating length
+		str = str.trim();
+
+		// Only add ellipsis if the string was actually truncated
+		if (!str.length || str.length <= length) {
+			return str;
+		}
+
 		if (tail === 'false') tail = '';
 		if (tail === 'true') tail = '…';
 		tail = !tail && tail !== '' ? '…' : tail;
-
 		return str.slice(0, length).trim() + tail;
 	}
 }
 
 export { UmbUfmTruncateFilterApi as api };
+export { UmbUfmTruncateFilterApi };