add unit tests for EnhanceAffiliateLinks

Author: George Haberis

dotcom-rendering/src/components/EnhanceAffiliateLinks.test.tsx

@@ -0,0 +1,84 @@
+import '@testing-library/jest-dom';
+import { render } from '@testing-library/react';
+import { useBetaAB } from '../lib/useAB';
+import { EnhanceAffiliateLinks } from './EnhanceAffiliateLinks.importable';
+
+// Mock the useAB module
+jest.mock('../lib/useAB', () => ({
+	useBetaAB: jest.fn(),
+}));
+
+describe('EnhanceAffiliateLinks', () => {
+	beforeEach(() => {
+		// Clear the DOM before each test
+		document.body.innerHTML = '';
+		jest.restoreAllMocks();
+	});
+
+	it('should not modify links if no Skimlinks are present', () => {
+		document.body.innerHTML = `
+            <a href="https://example.com">Not a Skimlink</a>
+        `;
+
+		render(<EnhanceAffiliateLinks />);
+
+		const link = document.querySelector('a');
+		expect(link?.href).toBe('https://example.com/');
+	});
+
+	it('should append xcust parameter to Skimlinks with refferer set to none if unavailable', () => {
+		Object.defineProperty(document, 'referrer', {
+			value: '',
+			configurable: true,
+		});
+
+		document.body.innerHTML = `
+            <a href="https://go.skimresources.com/?id=12345">Skimlink</a>
+        `;
+
+		render(<EnhanceAffiliateLinks />);
+
+		const link = document.querySelector('a');
+		expect(link?.href).toContain(
+			'xcust=referrer%7Cnone%7CaccountId%7C12345',
+		);
+	});
+
+	it('should append xcust parameter to Skimlinks with refferer set if available', () => {
+		Object.defineProperty(document, 'referrer', {
+			value: 'https://foo.com',
+			configurable: true,
+		});
+
+		document.body.innerHTML = `
+            <a href="https://go.skimresources.com/?id=12345">Skimlink</a>
+        `;
+
+		render(<EnhanceAffiliateLinks />);
+
+		const link = document.querySelector('a');
+		expect(link?.href).toContain(
+			'xcust=referrer%7Cfoo.com%7CaccountId%7C12345',
+		);
+	});
+
+	it('should include AB test participations in xcust if present', () => {
+		document.body.innerHTML = `
+            <a href="https://go.skimresources.com/?id=12345">Skimlink</a>
+        `;
+
+		(useBetaAB as jest.Mock).mockReturnValue({
+			getParticipations: () => ({
+				test1: 'variantA',
+				test2: 'variantB',
+			}),
+		});
+
+		render(<EnhanceAffiliateLinks />);
+
+		const link = document.querySelector('a');
+		expect(link?.href).toContain(
+			'xcust=referrer%7Cfoo.com%7CaccountId%7C12345%7CabTestParticipations%7Ctest1%3AvariantA%2Ctest2%3AvariantB',
+		);
+	});
+});