PM-3203 - use utm cookies on the login & signup links

Author: vas3a

src/lib/components/user-area/UserArea.svelte

@@ -5,6 +5,7 @@
   import { AUTH0_AUTHENTICATOR_URL } from 'lib/config';
   import { AUTH_USER_ROLE } from 'lib/config/auth';
   import { DISABLE_NUDGES } from "lib/config/profile-toasts.config";
+  import { appendUtmParamsToUrl } from 'lib/functions/utm-cookies.handler';
 
   import ToolSelector from '../tool-selector/ToolSelector.svelte';
 
@@ -65,12 +66,15 @@
   function onSignIn(signup?: any) {
     const locationHref = `${window.location.origin}${window.location.pathname}`
 
-    const signupUrl = [
+    let signupUrl = [
       `${AUTH0_AUTHENTICATOR_URL}?retUrl=${encodeURIComponent(locationHref)}`,
       signup === true ? '&mode=signUp' : '',
       $ctx.signupUtmCodes,
     ].filter(Boolean).join('&')
 
+    // Append UTM parameters from cookie if they exist
+    signupUrl = appendUtmParamsToUrl(signupUrl);
+
     window.location.href = signupUrl;
   }
 

src/lib/functions/utm-cookies.handler.ts

@@ -199,3 +199,40 @@ export function getUtmCookie(): UtmParams | null {
     return null;
   }
 }
+
+/**
+ * Appends UTM parameters from the tc_utm cookie to a given URL
+ * Only appends parameters that exist in the cookie
+ * @param url - The base URL to append parameters to
+ * @returns URL with UTM parameters appended, or original URL if no cookie exists
+ */
+export function appendUtmParamsToUrl(url: string): string {
+  if (!url) {
+    return url;
+  }
+
+  const utmParams = getUtmCookie();
+  if (!utmParams || Object.keys(utmParams).length === 0) {
+    return url;
+  }
+
+  try {
+    const urlObj = new URL(url, window.location.origin);
+    
+    // Append only the UTM parameters that exist in the cookie
+    if (utmParams.utm_source) {
+      urlObj.searchParams.set('utm_source', utmParams.utm_source);
+    }
+    if (utmParams.utm_medium) {
+      urlObj.searchParams.set('utm_medium', utmParams.utm_medium);
+    }
+    if (utmParams.utm_campaign) {
+      urlObj.searchParams.set('utm_campaign', utmParams.utm_campaign);
+    }
+    
+    return urlObj.toString();
+  } catch (error) {
+    console.warn('Error appending UTM parameters to URL:', error);
+    return url;
+  }
+}