tor-browser

commit 81f7f765376fa7dbf278cc9edec9d8f4a06bd6ad
parent 730809f3983bb5d9ecaed7c305fea480f3f1e575
Author: Irene Ni <ini@mozilla.com>
Date:   Thu,  8 Jan 2026 21:56:22 +0000

Bug 2008733 - Use random tile as fallback if no frecency match is found. r=nbarrett,home-newtab-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D278193

Diffstat:
M
browser/extensions/newtab/lib/TopSitesFeed.sys.mjs
 | 
22
++++++++++++++++------
M
browser/extensions/newtab/test/xpcshell/test_TopSitesFeed_frecencyDeduping.js
 | 
5
+++++
M
browser/extensions/newtab/test/xpcshell/test_TopSitesFeed_frecencyRanking.js
 | 
44
++++++++++++++++++++++++++++++++++++++------

3 files changed, 59 insertions(+), 12 deletions(-)
diff --git a/browser/extensions/newtab/lib/TopSitesFeed.sys.mjs b/browser/extensions/newtab/lib/TopSitesFeed.sys.mjs
@@ -1391,13 +1391,23 @@ export class TopSitesFeed {
     ) {
       const { values } = this.store.getState().Prefs;
       const numItems = values?.trainhopConfig?.sov?.numItems;
+      const randomSponsorEnabled = values?.trainhopConfig?.sov?.random_sponsor;
+
+      if (!randomSponsorEnabled) {
+        candidates = await this.frecencyBoostProvider.fetch(numItems);
+        // If we have a matched set of candidates,
+        // we can check if it's an exposure event.
+        if (candidates.length) {
+          this.frecencyBoostedSpocsExposureEvent();
+        }
+      }
 
-      candidates = await this.frecencyBoostProvider.fetch(numItems);
-
-      // If we have a matched set of candidates,
-      // we can check if it's an exposure event.
-      if (candidates.length) {
-        this.frecencyBoostedSpocsExposureEvent();
+      if (!candidates.length) {
+        const randomTile =
+          await this.frecencyBoostProvider.retrieveRandomFrecencyTile();
+        if (randomTile) {
+          candidates = [randomTile];
+        }
       }
     }
     return candidates;
diff --git a/browser/extensions/newtab/test/xpcshell/test_TopSitesFeed_frecencyDeduping.js b/browser/extensions/newtab/test/xpcshell/test_TopSitesFeed_frecencyDeduping.js
@@ -85,6 +85,11 @@ async function getTopSitesFeedForTest(
     .stub(feed.frecencyBoostProvider, "_frecencyBoostedSponsors")
     .value(frecencyBoostedSponsors);
 
+  // Stub random fallback to return null for testing deduping logic.
+  sandbox
+    .stub(feed.frecencyBoostProvider, "retrieveRandomFrecencyTile")
+    .returns(null);
+
   // We need to refresh, because TopSitesFeed's
   // DEFAULT_TOP_SITES acts like a singleton.
   DEFAULT_TOP_SITES.length = 0;
diff --git a/browser/extensions/newtab/test/xpcshell/test_TopSitesFeed_frecencyRanking.js b/browser/extensions/newtab/test/xpcshell/test_TopSitesFeed_frecencyRanking.js
@@ -109,12 +109,13 @@ add_task(async function test_frecency_sponsored_topsites() {
   {
     info(
       "TopSitesFeed.fetchFrecencyBoostedSpocs - " +
-        "Should return an empty array with no history"
+        "Should return random fallback tile with no history"
     );
     const feed = await getTopSitesFeedForTest(sandbox);
 
     const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
-    Assert.equal(frecencyBoostedSpocs.length, 0);
+    Assert.equal(frecencyBoostedSpocs.length, 1);
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost-random");
 
     sandbox.restore();
   }
@@ -190,6 +191,7 @@ add_task(async function test_frecency_sponsored_topsites() {
     const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
     Assert.equal(frecencyBoostedSpocs.length, 1);
     Assert.equal(frecencyBoostedSpocs[0].hostname, "domain1");
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost");
 
     sandbox.restore();
   }
@@ -210,13 +212,14 @@ add_task(async function test_frecency_sponsored_topsites() {
     const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
     Assert.equal(frecencyBoostedSpocs.length, 1);
     Assert.equal(frecencyBoostedSpocs[0].hostname, "domain1");
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost");
 
     sandbox.restore();
   }
   {
     info(
       "TopSitesFeed.fetchFrecencyBoostedSpocs - " +
-        "Should not return a match with a different subdomain"
+        "Should not return a match with a different subdomain (returns random fallback)"
     );
     const feed = await getTopSitesFeedForTest(sandbox, {
       frecent: [
@@ -228,7 +231,8 @@ add_task(async function test_frecency_sponsored_topsites() {
     });
 
     const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
-    Assert.equal(frecencyBoostedSpocs.length, 0);
+    Assert.equal(frecencyBoostedSpocs.length, 1);
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost-random");
 
     sandbox.restore();
   }
@@ -249,13 +253,14 @@ add_task(async function test_frecency_sponsored_topsites() {
     const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
     Assert.equal(frecencyBoostedSpocs.length, 1);
     Assert.equal(frecencyBoostedSpocs[0].hostname, "sub.domain1");
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost");
 
     sandbox.restore();
   }
   {
     info(
       "TopSitesFeed.fetchFrecencyBoostedSpocs - " +
-        "Should not match a partial domain"
+        "Should not match a partial domain (returns random fallback)"
     );
     const feed = await getTopSitesFeedForTest(sandbox, {
       frecent: [
@@ -267,7 +272,34 @@ add_task(async function test_frecency_sponsored_topsites() {
     });
 
     const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
-    Assert.equal(frecencyBoostedSpocs.length, 0);
+    Assert.equal(frecencyBoostedSpocs.length, 1);
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost-random");
+
+    sandbox.restore();
+  }
+  {
+    info(
+      "TopSitesFeed.fetchFrecencyBoostedSpocs - " +
+        "Control group always returns random tile (ignores frecency matches)"
+    );
+    const feed = await getTopSitesFeedForTest(sandbox, {
+      frecent: [
+        {
+          url: "https://domain1.com",
+          frecency: 1234,
+        },
+      ],
+    });
+
+    feed.store.state.Prefs.values.trainhopConfig = {
+      sov: {
+        random_sponsor: true,
+      },
+    };
+
+    const frecencyBoostedSpocs = await feed.fetchFrecencyBoostedSpocs();
+    Assert.equal(frecencyBoostedSpocs.length, 1);
+    Assert.equal(frecencyBoostedSpocs[0].type, "frecency-boost-random");
 
     sandbox.restore();
   }