✨(frontend) match event properties in posthog e2e helper

Asserting only on the event name is not enough when the same event is
emitted from multiple call sites with different payloads. Expose
expectEventSentWithProps so specs can pin down the expected slot or
context, and keep the captured properties available alongside the
existing names array.

src/frontend/apps/e2e/__tests__/app-drive/utils/posthog-utils.ts

@@ -2,6 +2,11 @@ import { expect, Page } from "@playwright/test";
 
 const FAKE_POSTHOG_HOST = "http://fake-ph.test";
 
+type CapturedEvent = {
+  event: string;
+  properties: Record<string, unknown>;
+};
+
 /**
  * Intercepts the config API to enable PostHog with a fake key and
  * captures all PostHog events sent by the page.
@@ -9,12 +14,14 @@ const FAKE_POSTHOG_HOST = "http://fake-ph.test";
  * Must be called **before** any page navigation (e.g. before `page.goto`).
  *
  * @returns An object with:
- *  - `events`: the live array of captured event names
- *  - `expectEventSent(name, timeout?)`: assertion helper that polls
- *     until the given event appears
+ *  - `events`: the live array of captured events with their properties
+ *  - `expectEventSent(name, timeout?)`: polls until the given event name appears
+ *  - `expectEventSentWithProps(name, props, timeout?)`: polls until at least
+ *     one captured event matches the name AND has every entry in `props`
+ *     as a strict equality match
  */
 export const setupPosthogEventCapture = async (page: Page) => {
-  const events: string[] = [];
+  const events: CapturedEvent[] = [];
 
   await page.route("**/api/v1.0/config/**", async (route) => {
     const response = await route.fetch();
@@ -28,7 +35,10 @@ export const setupPosthogEventCapture = async (page: Page) => {
     try {
       const postData = JSON.parse(route.request().postData() ?? "{}");
       if (postData.event) {
-        events.push(postData.event);
+        events.push({
+          event: postData.event,
+          properties: postData.properties ?? {},
+        });
       }
     } catch {
       // ignore non-JSON requests (e.g. /decide)
@@ -42,9 +52,29 @@ export const setupPosthogEventCapture = async (page: Page) => {
 
   const expectEventSent = async (eventName: string, timeout = 5000) => {
     await expect
-      .poll(() => events.includes(eventName), { timeout })
+      .poll(() => events.some((e) => e.event === eventName), { timeout })
       .toBe(true);
   };
 
-  return { events, expectEventSent };
+  const expectEventSentWithProps = async (
+    eventName: string,
+    expectedProps: Record<string, unknown>,
+    timeout = 5000,
+  ) => {
+    await expect
+      .poll(
+        () =>
+          events.some(
+            (e) =>
+              e.event === eventName &&
+              Object.entries(expectedProps).every(
+                ([k, v]) => e.properties[k] === v,
+              ),
+          ),
+        { timeout },
+      )
+      .toBe(true);
+  };
+
+  return { events, expectEventSent, expectEventSentWithProps };
 };