Misc improvements

- improve integration test coverage
- rely on genkit's user_engagement function
- clean up deps

ai-user-engagement/functions/.env

@@ -0,0 +1 @@
+GENKIT_ENV=prod

ai-user-engagement/functions/.env.local

@@ -0,0 +1 @@
+GENKIT_ENV=dev

ai-user-engagement/functions/integration-tests/integration-test.spec.ts

@@ -1,9 +1,14 @@
 import axios from "axios";
 import { expect } from "chai";
+import { readFileSync } from 'fs';
 
 describe("firebase-ai-user-engagement", () => {
   const uri = "http://localhost:5001/demo-test/us-central1/ext-ai-user-engagement-collectEngagement/";
 
+  function delay(ms: number) {
+    return new Promise( resolve => setTimeout(resolve, ms) );
+  }
+
   it("should collect user feedback", async () => {
     const request = {
       name: "featureName",
@@ -16,9 +21,30 @@ describe("firebase-ai-user-engagement", () => {
     };
 
     const res = await axios.post(uri, request);
+    expect(res.data).to.eql({});
 
-    return expect(res.data).to.eql({});
-  }).timeout(10000);
+    await delay(5000);
+
+    // Wait for emulator logs to contain the user feedback message. We do this
+    // by explicitly setting the Genkit env to "dev" (by using .env.local
+    // config), which forces logs to be written to console, and by redirecting
+    // emulator output to a tmp file (see package.json).
+    let tries = 5;
+    let foundLog = false;
+    while (tries > 0) {
+      const testLogs = readFileSync('/tmp/engagement_test_output', 'utf8');
+      if (testLogs.indexOf("UserFeedback[featureName]") > 0) {
+        foundLog = true;
+        break;
+      } else {
+        console.log('.');
+      }
+      await delay(10000); // wait 10s
+      tries--;
+    }
+
+    return expect(foundLog).to.be.true;
+  }).timeout(60000);
 
   it("should collect user acceptance", async () => {
     const request = {