feat: frontend unit tests

frontend/tests/utils/helpers/imageExtension.test.ts

@@ -0,0 +1,47 @@
+import { imageExtension } from '../../../src/static/js/utils/helpers/imageExtension';
+
+describe('js/utils/helpers', () => {
+    describe('imageExtension', () => {
+        // @todo: 'imageExtension' behaves as a 'fileExtension' function. It should be renamed...
+        test('Returns the extension for a typical filename', () => {
+            expect(imageExtension('photo.png')).toBe('png');
+            expect(imageExtension('document.pdf')).toBe('pdf');
+        });
+
+        test('Returns the last segment for filenames with multiple dots', () => {
+            expect(imageExtension('archive.tar.gz')).toBe('gz');
+            expect(imageExtension('backup.2024.12.31.zip')).toBe('zip');
+        });
+
+        // @todo: It shouldn't happen. Fix that
+        test('Returns the entire string when there is no dot in the filename', () => {
+            expect(imageExtension('file')).toBe('file');
+            expect(imageExtension('README')).toBe('README');
+        });
+
+        test('Handles hidden files that start with a dot', () => {
+            expect(imageExtension('.gitignore')).toBe('gitignore');
+            expect(imageExtension('.env.local')).toBe('local');
+        });
+
+        test('Returns undefined for falsy or empty inputs', () => {
+            expect(imageExtension('')).toBeUndefined();
+            expect(imageExtension(undefined as unknown as string)).toBeUndefined();
+            expect(imageExtension(null as unknown as string)).toBeUndefined();
+        });
+
+        test('Extracts the extension from URL-like paths', () => {
+            expect(imageExtension('https://example.com/images/avatar.jpeg')).toBe('jpeg');
+            expect(imageExtension('/static/assets/icons/favicon.ico')).toBe('ico');
+        });
+
+        test('Preserves case of the extension', () => {
+            expect(imageExtension('UPPER.CASE.JPG')).toBe('JPG');
+            expect(imageExtension('Mixed.Extension.PnG')).toBe('PnG');
+        });
+
+        test('Returns empty string when the filename ends with a trailing dot', () => {
+            expect(imageExtension('weird.')).toBe('');
+        });
+    });
+});