first pass analytics redo

tests/stats-analytics.test.ts

@@ -0,0 +1,31 @@
+import { describe, test, expect } from 'bun:test';
+import { parseAcquisition } from '$lib/utils/acquisition';
+
+describe('parseAcquisition', () => {
+	test('extracts utm parameters and ref', () => {
+		const a = parseAcquisition('?utm_source=bluesky&utm_medium=social&utm_campaign=launch', '');
+		expect(a.utm_source).toBe('bluesky');
+		expect(a.utm_medium).toBe('social');
+		expect(a.utm_campaign).toBe('launch');
+	});
+
+	test('falls back to ref for the source', () => {
+		expect(parseAcquisition('?ref=hn', '').utm_source).toBe('hn');
+	});
+
+	test('keeps an external referrer', () => {
+		const a = parseAcquisition('', 'https://news.ycombinator.com/item?id=1');
+		expect(a.referrer).toBe('https://news.ycombinator.com/item?id=1');
+	});
+
+	test('blank and whitespace values become null', () => {
+		const a = parseAcquisition('?utm_source=%20%20', '');
+		expect(a.utm_source).toBeNull();
+		expect(a.referrer).toBeNull();
+	});
+
+	test('caps absurdly long values', () => {
+		const a = parseAcquisition(`?utm_source=${'x'.repeat(500)}`, '');
+		expect(a.utm_source!.length).toBe(256);
+	});
+});