fix(tracker): emit empty referrer and normalize 'direct' server-side

Tracker now sends empty string when document.referrer is missing; the
API normalizes legacy 'direct' values alongside empty strings in the
isDirect / referrer CASE expressions. Also adds the full set of
Telegram domains to the referrer classification list.

Author: izadoesdev

apps/api/src/query/expressions.ts

@@ -200,7 +200,7 @@ export const Expressions = {
 	referrer: {
 		normalized: expr(`
 			CASE 
-				WHEN referrer = '' OR referrer IS NULL THEN 'direct'
+				WHEN referrer = '' OR referrer IS NULL OR referrer = 'direct' THEN 'direct'
 				WHEN domain(referrer) LIKE '%.google.com%' OR domain(referrer) LIKE 'google.com%' THEN 'https://google.com'
 				WHEN domain(referrer) LIKE '%.facebook.com%' OR domain(referrer) LIKE 'facebook.com%' THEN 'https://facebook.com'
 				WHEN domain(referrer) LIKE '%.twitter.com%' OR domain(referrer) LIKE 'twitter.com%' OR domain(referrer) LIKE 't.co%' THEN 'https://twitter.com'
@@ -210,7 +210,7 @@ export const Expressions = {
 
 		domain: expr("domain(referrer)"),
 
-		isDirect: expr("referrer = '' OR referrer IS NULL"),
+		isDirect: expr("referrer = '' OR referrer IS NULL OR referrer = 'direct'"),
 
 		isExternal: (websiteDomain: string) =>
 			expr(`

packages/shared/src/lists/referrers.ts

@@ -2584,7 +2584,11 @@ export const referrers: Record<string, { type: string; name: string }> = {
 	"vkontakte.ru": { type: "social", name: "Vkontakte" },
 	"weibo.com": { type: "social", name: "Weibo" },
 	"t.cn": { type: "social", name: "Weibo" },
+	"t.me": { type: "social", name: "Telegram" },
+	"telegram.org": { type: "social", name: "Telegram" },
+	"telegram.me": { type: "social", name: "Telegram" },
 	"web.telegram.org": { type: "social", name: "Telegram" },
+	"desktop.telegram.org": { type: "social", name: "Telegram" },
 	"org.telegram.messenger": { type: "social", name: "Telegram" },
 	"org.telegram.messenger.web": { type: "social", name: "Telegram" },
 	"org.aka.messenger": { type: "social", name: "Telegram" },

packages/tracker/src/core/tracker.ts

@@ -392,7 +392,7 @@ export class BaseTracker {
 				window.location.search +
 				window.location.hash,
 			title: document.title,
-			referrer: document.referrer || "direct",
+			referrer: document.referrer || "",
 			viewport_size: width && height ? `${width}x${height}` : undefined,
 			timezone: this.cachedTimezone,
 			language: navigator.language,

packages/tracker/tests/context.spec.ts

@@ -524,7 +524,7 @@ test.describe("Event Context", () => {
 			expect(payload?.referrer).toBe("https://google.com/search?q=test");
 		});
 
-		test("uses 'direct' when no referrer", async ({ page }) => {
+		test("uses empty string when no referrer", async ({ page }) => {
 			await page.goto("/test");
 			await page.evaluate(() => {
 				// Clear any referrer
@@ -548,7 +548,7 @@ test.describe("Event Context", () => {
 			const request = await requestPromise;
 			const payload = findEvent(request, (e) => e.name === "screen_view");
 
-			expect(payload?.referrer).toBe("direct");
+			expect(payload?.referrer).toBe("");
 		});
 	});