Merging upstream version 126.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

19 files changed, 1198 insertions, 104 deletions

diff --git a/testing/web-platform/tests/fledge/tentative/TODO b/testing/web-platform/tests/fledge/tentative/TODO
index 0f68a7c914..6fd378c035 100644
--- a/testing/web-platform/tests/fledge/tentative/TODO
+++ b/testing/web-platform/tests/fledge/tentative/TODO
@@ -47,6 +47,7 @@ Need tests for (likely not a complete list):
 * adAuctionConfig passed to reportResult().
 * Component auctions.
   * Including cross-origin sellers.
+  * Timeouts (seller timeout, buyer timeout, reporting timeout).
 * browserSignals fields in scoring/bidding methods.
 * In reporting methods, browserSignals fields: topLevelSeller,
     componentSeller, modifiedBid, adCost, madeHighestScoringOtherBid
@@ -88,3 +89,4 @@ If possible:
 * Signals request batching. This is an optional feature, so can't require it,
     but maybe a test where batching could be used, and make sure things work,
     whether batching is used or not?
+* reporting timeout being 0.
diff --git a/testing/web-platform/tests/fledge/tentative/additional-bids.https.window.js b/testing/web-platform/tests/fledge/tentative/additional-bids.https.window.js
index 0e1d22c261..965f9a60c7 100644
--- a/testing/web-platform/tests/fledge/tentative/additional-bids.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/additional-bids.https.window.js
@@ -10,15 +10,8 @@
 // This file contains tests for additional bids and negative targeting.
 //
 // TODO:
-// - test that an negatively targeted additional bid is suppressed.
-// - test that an incorrectly signed additional bid is not negative targeted.
-// - test that an missing-signature additional bid is not negative targeted.
-// - test that an additional bid with some correct signatures can be negative.
-//       negative targeted for those negative interest groups whose signatures
-//       match.
-// - test an additional bid with multiple negative interest groups.
-// - test that multiple negative interest groups with mismatched joining origins
-//       is not negative targeted.
+// - test that an additional bid with some correct signatures can be negative
+//       targeted for those negative interest groups whose signatures match.
 // - test that additional bids can be fetched using an iframe navigation.
 // - test that additional bids are not fetched using an iframe navigation for
 //      which the `adAuctionHeaders=true` attribute is not specified.
@@ -26,12 +19,19 @@
 //      `adAuctionHeaders: true` is not specified.
 // - test that an additional bid with an incorrect auction nonce is not used
 //       included in an auction. Same for seller and top-level seller.
+// - lots of tests for different types of malformed additional bids, e.g.
+//       missing fields, malformed signature, invalid currency code,
+//       missing joining origin for multiple negative interest groups, etc.
 // - test that correctly formatted additional bids are included in an auction
 //       when fetched alongside malformed additional bid headers by a Fetch
-//       request.
+//       request (both invalid headers and invalid additional bids)
+// - test that an additional bid is rejected if its from a buyer who is not
+//       allowed to participate in the auction.
+// - test that an additional bid is rejected if its currency doesn't match the
+//       buyer's associated per-buyer currency from the auction config.
 // - test that correctly formatted additional bids are included in an auction
 //       when fetched alongside malformed additional bid headers by an iframe
-//       navigation.
+//       navigation (both invalid headers and invalid additional bids).
 // - test that reportWin is not used for reporting an additional bid win.
 // - test that additional bids can *not* be fetched from iframe subresource
 //       requests.
@@ -80,6 +80,9 @@
 // for ad auction headers interception to associate it with this auction.
 const SINGLE_SELLER_AUCTION_SELLER = window.location.origin;
 
+const ADDITIONAL_BID_SECRET_KEY = 'nWGxne/9WmC6hEr0kuwsxERJxWl7MmkZcDusAxyuf2A=';
+const ADDITIONAL_BID_PUBLIC_KEY = '11qYAYKxCrfVS/7TyWQHOg7hcvPapiMlrwIaaPcHURo=';
+
 // Single-seller auction with a single buyer who places a single additional
 // bid. As the only bid, this wins.
 subsetTest(promise_test, async test => {
@@ -88,12 +91,12 @@ subsetTest(promise_test, async test => {
   const seller = SINGLE_SELLER_AUCTION_SELLER;
 
   const buyer = OTHER_ORIGIN1;
-  const additionalBid = createAdditionalBid(
+  const additionalBid = additionalBidHelper.createAdditionalBid(
       uuid, auctionNonce, seller, buyer, 'horses', 1.99);
 
   await runAdditionalBidTest(
       test, uuid, [buyer], auctionNonce,
-      fetchAdditionalBids(seller, [additionalBid]),
+      additionalBidHelper.fetchAdditionalBids(seller, [additionalBid]),
       /*highestScoringOtherBid=*/0,
       /*winningAdditionalBidId=*/'horses');
 }, 'single valid additional bid');
@@ -105,16 +108,17 @@ subsetTest(promise_test, async test => {
   const seller = SINGLE_SELLER_AUCTION_SELLER;
 
   const buyer1 = OTHER_ORIGIN1;
-  const additionalBid1 = createAdditionalBid(
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
       uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
 
   const buyer2 = OTHER_ORIGIN2;
-  const additionalBid2 = createAdditionalBid(
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
       uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
 
   await runAdditionalBidTest(
       test, uuid, [buyer1, buyer2], auctionNonce,
-      fetchAdditionalBids(seller, [additionalBid1, additionalBid2]),
+      additionalBidHelper.fetchAdditionalBids(
+          seller, [additionalBid1, additionalBid2]),
       /*highestScoringOtherBid=*/1.99,
       /*winningAdditionalBidId=*/'planes');
 }, 'two valid additional bids');
@@ -127,20 +131,241 @@ subsetTest(promise_test, async test => {
   const seller = SINGLE_SELLER_AUCTION_SELLER;
 
   const buyer1 = OTHER_ORIGIN1;
-  const additionalBid1 = createAdditionalBid(
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
       uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
 
   const buyer2 = OTHER_ORIGIN2;
-  const additionalBid2 = createAdditionalBid(
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
       uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
 
-
   await runAdditionalBidTest(
     test, uuid, [buyer1, buyer2], auctionNonce,
     Promise.all([
-        fetchAdditionalBids(seller, [additionalBid1]),
-        fetchAdditionalBids(seller, [additionalBid2])
+        additionalBidHelper.fetchAdditionalBids(seller, [additionalBid1]),
+        additionalBidHelper.fetchAdditionalBids(seller, [additionalBid2])
     ]),
     /*highestScoringOtherBid=*/1.99,
     /*winningAdditionalBidId=*/'planes');
 }, 'two valid additional bids from two distinct Fetch requests');
+
+// Single-seller auction with a single additional bid. Because this additional
+// bid is filtered by negative targeting, this auction has no winner.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const negativeInterestGroupName = 'already-owns-a-plane';
+
+  const buyer = OTHER_ORIGIN1;
+  const additionalBid = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer, 'planes', 2.99);
+  additionalBidHelper.addNegativeInterestGroup(
+      additionalBid, negativeInterestGroupName);
+  additionalBidHelper.signWithSecretKeys(
+      additionalBid, [ADDITIONAL_BID_SECRET_KEY]);
+
+  await joinNegativeInterestGroup(
+      test, buyer, negativeInterestGroupName, ADDITIONAL_BID_PUBLIC_KEY);
+
+  await runBasicFledgeTestExpectingNoWinner(
+      test, uuid,
+      { interestGroupBuyers: [buyer],
+        auctionNonce: auctionNonce,
+        additionalBids: additionalBidHelper.fetchAdditionalBids(
+            seller, [additionalBid])});
+}, 'one additional bid filtered by negative targeting, so auction has no ' +
+   'winner');
+
+// Single-seller auction with a two buyers competing with additional bids.
+// The higher of these has a negative interest group specified, and that
+// negative interest group has been joined, so the lower bid wins.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const negativeInterestGroupName = 'already-owns-a-plane';
+
+  const buyer1 = OTHER_ORIGIN1;
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
+
+  const buyer2 = OTHER_ORIGIN2;
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
+  additionalBidHelper.addNegativeInterestGroup(
+      additionalBid2, negativeInterestGroupName);
+  additionalBidHelper.signWithSecretKeys(
+      additionalBid2, [ADDITIONAL_BID_SECRET_KEY]);
+
+  await joinNegativeInterestGroup(
+      test, buyer2, negativeInterestGroupName, ADDITIONAL_BID_PUBLIC_KEY);
+
+  await runAdditionalBidTest(
+    test, uuid, [buyer1, buyer2], auctionNonce,
+    additionalBidHelper.fetchAdditionalBids(
+        seller, [additionalBid1, additionalBid2]),
+    /*highestScoringOtherBid=*/0,
+    /*winningAdditionalBidId=*/'horses');
+}, 'higher additional bid is filtered by negative targeting, so ' +
+   'lower additional bid win');
+
+// Same as above, except that the bid is missing a signature, so that the
+// negative targeting interest group is ignored, and the higher bid, which
+// would have otherwise been filtered by negative targeting, wins.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const negativeInterestGroupName = 'already-owns-a-plane';
+
+  const buyer1 = OTHER_ORIGIN1;
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
+
+  const buyer2 = OTHER_ORIGIN2;
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
+  additionalBidHelper.addNegativeInterestGroup(
+      additionalBid2, negativeInterestGroupName);
+
+  await joinNegativeInterestGroup(
+      test, buyer2, negativeInterestGroupName, ADDITIONAL_BID_PUBLIC_KEY);
+
+  await runAdditionalBidTest(
+    test, uuid, [buyer1, buyer2], auctionNonce,
+    additionalBidHelper.fetchAdditionalBids(
+        seller, [additionalBid1, additionalBid2]),
+    /*highestScoringOtherBid=*/1.99,
+    /*winningAdditionalBidId=*/'planes');
+}, 'higher additional bid is filtered by negative targeting, but it is ' +
+   'missing a signature, so it still wins');
+
+// Same as above, except that the bid is signed incorrectly, so that the
+// negative targeting interest group is ignored, and the higher bid, which
+// would have otherwise been filtered by negative targeting, wins.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const negativeInterestGroupName = 'already-owns-a-plane';
+
+  const buyer1 = OTHER_ORIGIN1;
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
+
+  const buyer2 = OTHER_ORIGIN2;
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
+  additionalBidHelper.addNegativeInterestGroup(
+      additionalBid2, negativeInterestGroupName);
+  additionalBidHelper.incorrectlySignWithSecretKeys(
+      additionalBid2, [ADDITIONAL_BID_SECRET_KEY]);
+
+  await joinNegativeInterestGroup(
+      test, buyer2, negativeInterestGroupName, ADDITIONAL_BID_PUBLIC_KEY);
+
+  await runAdditionalBidTest(
+    test, uuid, [buyer1, buyer2], auctionNonce,
+    additionalBidHelper.fetchAdditionalBids(
+        seller, [additionalBid1, additionalBid2]),
+    /*highestScoringOtherBid=*/1.99,
+    /*winningAdditionalBidId=*/'planes');
+}, 'higher additional bid is filtered by negative targeting, but it has an ' +
+   'invalid signature, so it still wins');
+
+// A test of an additional bid with multiple negative interest groups.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const negativeInterestGroupName1 = 'already-owns-a-plane';
+  const negativeInterestGroupName2 = 'another-negative-interest-group';
+
+  const buyer1 = OTHER_ORIGIN1;
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
+
+  const buyer2 = OTHER_ORIGIN2;
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
+  additionalBidHelper.addNegativeInterestGroups(
+      additionalBid2, [negativeInterestGroupName1, negativeInterestGroupName2],
+      /*joiningOrigin=*/window.location.origin);
+  additionalBidHelper.signWithSecretKeys(
+      additionalBid2, [ADDITIONAL_BID_SECRET_KEY]);
+
+  await joinNegativeInterestGroup(
+      test, buyer2, negativeInterestGroupName1, ADDITIONAL_BID_PUBLIC_KEY);
+
+  await runAdditionalBidTest(
+    test, uuid, [buyer1, buyer2], auctionNonce,
+    additionalBidHelper.fetchAdditionalBids(
+        seller, [additionalBid1, additionalBid2]),
+    /*highestScoringOtherBid=*/0,
+    /*winningAdditionalBidId=*/'horses');
+}, 'higher additional bid is filtered by negative targeting by two negative ' +
+   'interest groups, and since one is on the device, the lower bid wins');
+
+// Same as above, but with a mismatched joining origin.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const negativeInterestGroupName1 = 'already-owns-a-plane';
+  const negativeInterestGroupName2 = 'another-negative-interest-group';
+
+  const buyer1 = OTHER_ORIGIN1;
+  const additionalBid1 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer1, 'horses', 1.99);
+
+  const buyer2 = OTHER_ORIGIN2;
+  const additionalBid2 = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer2, 'planes', 2.99);
+  additionalBidHelper.addNegativeInterestGroups(
+      additionalBid2, [negativeInterestGroupName1, negativeInterestGroupName2],
+      /*joiningOrigin=*/OTHER_ORIGIN1);
+  additionalBidHelper.signWithSecretKeys(
+      additionalBid2, [ADDITIONAL_BID_SECRET_KEY]);
+
+  await joinNegativeInterestGroup(
+      test, buyer2, negativeInterestGroupName1, ADDITIONAL_BID_PUBLIC_KEY);
+
+  await runAdditionalBidTest(
+    test, uuid, [buyer1, buyer2], auctionNonce,
+    additionalBidHelper.fetchAdditionalBids(
+        seller, [additionalBid1, additionalBid2]),
+    /*highestScoringOtherBid=*/1.99,
+    /*winningAdditionalBidId=*/'planes');
+}, 'higher additional bid is filtered by negative targeting by two negative ' +
+   'interest groups, but because of a joining origin mismatch, it still wins');
+
+// Ensure that trusted seller signals are retrieved for additional bids.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const auctionNonce = await navigator.createAuctionNonce();
+  const seller = SINGLE_SELLER_AUCTION_SELLER;
+
+  const buyer = OTHER_ORIGIN1;
+  const additionalBid = additionalBidHelper.createAdditionalBid(
+      uuid, auctionNonce, seller, buyer, 'horses', 1.99);
+
+  let renderURL = createRenderURL(uuid);
+  await runBasicFledgeTestExpectingWinner(
+      test, uuid,
+      { interestGroupBuyers: [buyer],
+        auctionNonce: auctionNonce,
+        additionalBids: additionalBidHelper.fetchAdditionalBids(
+            seller, [additionalBid]),
+        decisionLogicURL: createDecisionScriptURL(
+            uuid,
+            { scoreAd:
+                `if(!"${renderURL}" in trustedScoringSignals.renderURL) ` +
+                  'throw "missing trusted signals";'}),
+        trustedScoringSignalsURL: TRUSTED_SCORING_SIGNALS_URL});
+}, 'trusted seller signals retrieved for additional bids');
diff --git a/testing/web-platform/tests/fledge/tentative/auction-config-passed-to-worklets.https.window.js b/testing/web-platform/tests/fledge/tentative/auction-config-passed-to-worklets.https.window.js
index c78a27bb87..9b12d077ba 100644
--- a/testing/web-platform/tests/fledge/tentative/auction-config-passed-to-worklets.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/auction-config-passed-to-worklets.https.window.js
@@ -6,7 +6,8 @@
 // META: variant=?1-5
 // META: variant=?6-10
 // META: variant=?11-15
-// META: variant=?16-last
+// META: variant=?16-20
+// META: variant=?21-last
 
 "use strict;"
 
@@ -206,3 +207,23 @@ makeTest({
               [{width: ' 100', height: '200.50px '},
                {width: ' 70.00sh ', height: '80.50sw'}]}
 });
+
+makeTest({
+  name: 'AuctionConfig.reportingTimeout with positive within-cap value.',
+  fieldName: 'reportingTimeout',
+  fieldValue: 100,
+});
+
+makeTest({
+  name: 'AuctionConfig.reportingTimeout above the cap value.',
+  fieldName: 'reportingTimeout',
+  fieldValue: 5000,
+  auctionConfigOverrides: {fieldValue: 1234567890}
+});
+
+makeTest({
+  name: 'AuctionConfig.reportingTimeout not provided',
+  fieldName: 'reportingTimeout',
+  fieldValue: 50,
+  auctionConfigOverrides: {fieldValue: undefined}
+});
\ No newline at end of file
diff --git a/testing/web-platform/tests/fledge/tentative/auction-config.https.window.js b/testing/web-platform/tests/fledge/tentative/auction-config.https.window.js
index 8fbdc95dfc..5fa4fa252f 100644
--- a/testing/web-platform/tests/fledge/tentative/auction-config.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/auction-config.https.window.js
@@ -10,7 +10,9 @@
 // META: variant=?21-25
 // META: variant=?26-30
 // META: variant=?31-35
-// META: variant=?36-last
+// META: variant=?36-40
+// META: variant=?40-45
+// META: variant=?46-last
 
 "use strict;"
 
@@ -86,6 +88,14 @@ const EXPECT_NO_WINNER = auctionResult => {
   assert_equals(auctionResult, null, 'Auction unexpected had a winner');
 };
 
+// Expect a winner (FencedFrameConfig).
+const EXPECT_WINNER =
+    auctionResult => {
+      assert_true(
+          auctionResult instanceof FencedFrameConfig,
+          'Auction did not return expected FencedFrameConfig');
+    }
+
 // Expect an exception of the given type.
 const EXPECT_EXCEPTION = exceptionType => auctionResult => {
   assert_not_equals(auctionResult, null, "got null instead of expected error");
@@ -130,6 +140,50 @@ makeTest({
 });
 
 makeTest({
+  name: 'valid trustedScoringSignalsURL',
+  expect: EXPECT_WINNER,
+  auctionConfigOverrides:
+      {trustedScoringSignalsURL: window.location.origin + '/resource.json'}
+});
+
+makeTest({
+  name: 'trustedScoringSignalsURL should not have a fragment',
+  expect: EXPECT_EXCEPTION(TypeError),
+  auctionConfigOverrides:
+      {trustedScoringSignalsURL: window.location.origin + '/resource.json#foo'}
+});
+
+makeTest({
+  name: 'trustedScoringSignalsURL with an empty fragment is not OK',
+  expect: EXPECT_EXCEPTION(TypeError),
+  auctionConfigOverrides:
+      {trustedScoringSignalsURL: window.location.origin + '/resource.json#'}
+});
+
+makeTest({
+  name: 'trustedScoringSignalsURL should not have a query',
+  expect: EXPECT_EXCEPTION(TypeError),
+  auctionConfigOverrides:
+      {trustedScoringSignalsURL: window.location.origin + '/resource.json?foo'}
+});
+
+makeTest({
+  name: 'trustedScoringSignalsURL with an empty query is not OK',
+  expect: EXPECT_EXCEPTION(TypeError),
+  auctionConfigOverrides:
+      {trustedScoringSignalsURL: window.location.origin + '/resource.json?'}
+});
+
+makeTest({
+  name: 'trustedScoringSignalsURL should not have embedded credentials',
+  expect: EXPECT_EXCEPTION(TypeError),
+  auctionConfigOverrides: {
+    trustedScoringSignalsURL: (window.location.origin + '/resource.json')
+                                  .replace('https://', 'https://user:pass@')
+  }
+});
+
+makeTest({
   name: 'trustedScoringSignalsURL is cross-origin with seller',
   expect: EXPECT_EXCEPTION(TypeError),
   auctionConfigOverrides: { trustedScoringSignalsURL: "https://example.com" },
@@ -420,9 +474,9 @@ subsetTest(promise_test, async test => {
         let bid = browserSignals.forDebuggingOnlyInCooldownOrLockout ? 1 : 2;
         return {bid: bid, render: '${renderURL}'};`,
       reportWin: `
-        if (browserSignals.bid == 1)
+        if (browserSignals.bid === 1)
           sendReportTo('${bidderReportURL1}');
-        if (browserSignals.bid == 2)
+        if (browserSignals.bid === 2)
           sendReportTo('${bidderReportURL2}');`
 
     })
@@ -443,9 +497,9 @@ subsetTest(promise_test, async test => {
             browserSignals.forDebuggingOnlyInCooldownOrLockout ? 1 : 2;
         return {desirability: desirability};`,
       reportResult: `
-        if (browserSignals.desirability == 1)
+        if (browserSignals.desirability === 1)
           sendReportTo('${sellerReportURL1}');
-        if (browserSignals.desirability == 2)
+        if (browserSignals.desirability === 2)
           sendReportTo('${sellerReportURL2}');`
     })
   };
diff --git a/testing/web-platform/tests/fledge/tentative/component-ads.https.window.js b/testing/web-platform/tests/fledge/tentative/component-ads.https.window.js
index 7e98570b9e..6b22585d57 100644
--- a/testing/web-platform/tests/fledge/tentative/component-ads.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/component-ads.https.window.js
@@ -61,7 +61,7 @@ async function runComponentAdLoadingTest(test, uuid, numComponentAdsInInterestGr
       `// "status" is passed to the beacon URL, to be verified by waitForObservedRequests().
        let status = "ok";
        const componentAds = window.fence.getNestedConfigs()
-       if (componentAds.length != 40)
+       if (componentAds.length !== 40)
          status = "unexpected getNestedConfigs() length";
        for (let i of ${JSON.stringify(componentAdsToLoad)}) {
          let fencedFrame = document.createElement("fencedframe");
@@ -144,7 +144,7 @@ subsetTest(promise_test, async test => {
      const nestedConfigsLength = window.fence.getNestedConfigs().length
      // "getNestedConfigs()" should return a list of 40 configs, to avoid leaking
      // whether there were any component URLs to the page.
-     if (nestedConfigsLength != 40)
+     if (nestedConfigsLength !== 40)
        status = "unexpected getNestedConfigs() length: " + nestedConfigsLength;
      window.fence.reportEvent({eventType: "beacon",
                                eventData: status,
diff --git a/testing/web-platform/tests/fledge/tentative/component-auction.https.window.js b/testing/web-platform/tests/fledge/tentative/component-auction.https.window.js
index c70532024c..015c20a5c2 100644
--- a/testing/web-platform/tests/fledge/tentative/component-auction.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/component-auction.https.window.js
@@ -685,7 +685,7 @@ subsetTest(promise_test, async test => {
   auctionConfig.componentAuctions[0].decisionLogicURL =
       createDecisionScriptURL(
           uuid,
-          { scoreAd: `if (browserSignals.renderURL != '${renderURL1}')
+          { scoreAd: `if (browserSignals.renderURL !== '${renderURL1}')
                         throw 'Wrong ad';`,
             reportResult: `sendReportTo('${seller1ReportURL}');`}
       );
@@ -696,7 +696,7 @@ subsetTest(promise_test, async test => {
       decisionLogicURL: createDecisionScriptURL(
           uuid,
           { origin: OTHER_ORIGIN1,
-            scoreAd: `if (browserSignals.renderURL != '${renderURL2}')
+            scoreAd: `if (browserSignals.renderURL !== '${renderURL2}')
                         throw 'Wrong ad';`,
             reportResult: `sendReportTo('${seller2ReportURL}');`}
       )
diff --git a/testing/web-platform/tests/fledge/tentative/cross-origin.https.window.js b/testing/web-platform/tests/fledge/tentative/cross-origin.https.window.js
index a8cf93049f..eed74c522f 100644
--- a/testing/web-platform/tests/fledge/tentative/cross-origin.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/cross-origin.https.window.js
@@ -356,7 +356,7 @@ subsetTest(promise_test, async test => {
                           throw "Wrong origin: " + interestGroup.owner;
                         if (!interestGroup.biddingLogicURL.startsWith("${bidderOrigin}"))
                           throw "Wrong origin: " + interestGroup.biddingLogicURL;
-                        if (interestGroup.ads[0].renderURL != "${renderURL}")
+                        if (interestGroup.ads[0].renderURL !== "${renderURL}")
                           throw "Wrong renderURL: " + interestGroup.ads[0].renderURL;
                         if (browserSignals.seller !== "${sellerOrigin}")
                           throw "Wrong origin: " + browserSignals.seller;`,
diff --git a/testing/web-platform/tests/fledge/tentative/currency.https.window.js b/testing/web-platform/tests/fledge/tentative/currency.https.window.js
index 9a33d12148..99943cecbf 100644
--- a/testing/web-platform/tests/fledge/tentative/currency.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/currency.https.window.js
@@ -501,7 +501,7 @@ subsetTest(promise_test, async test => {
     topLevelSellerScriptParamsOverride: {
       scoreAd: `
                 // scoreAd sees what's actually passed in.
-                if (bid != 9)
+                if (bid !== 9)
                   throw 'Wrong bid';
                 if (browserSignals.bidCurrency !== '???')
                   throw 'Wrong currency';`
diff --git a/testing/web-platform/tests/fledge/tentative/generate-bid-browser-signals.https.window.js b/testing/web-platform/tests/fledge/tentative/generate-bid-browser-signals.https.window.js
index 8687e3f296..c7078ae08a 100644
--- a/testing/web-platform/tests/fledge/tentative/generate-bid-browser-signals.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/generate-bid-browser-signals.https.window.js
@@ -939,7 +939,7 @@ subsetTest(promise_test, async test => {
                  if (!deepEquals(Object.keys(instance.exports), ["increment"]))
                    throw "Unexpected exports: " + JSON.stringify(instance.exports);
 
-                 if (instance.exports.increment(1) != 2)
+                 if (instance.exports.increment(1) !== 2)
                    throw "Unexpected increment result: " + instance.exports.increment(1);` })
       }
     });
diff --git a/testing/web-platform/tests/fledge/tentative/reporting-arguments.https.window.js b/testing/web-platform/tests/fledge/tentative/reporting-arguments.https.window.js
index c7c7120240..db6ef2d35a 100644
--- a/testing/web-platform/tests/fledge/tentative/reporting-arguments.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/reporting-arguments.https.window.js
@@ -259,7 +259,7 @@ subsetTest(promise_test, async test => {
     // reportResultSuccessCondition:
     `browserSignals.interestGroupName === undefined`,
     // reportWinSuccessCondition:
-    `browserSignals.interestGroupName === ''`
+    `browserSignals.interestGroupName === 'default name'`
   );
 }, 'browserSignals.interestGroupName test.');
 
@@ -303,3 +303,53 @@ await runReportArgumentValidationTest(
     uuid
   );
 }, 'browserSignals.madeHighestScoringOtherBid with other bid.');
+
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  await runReportTest(
+      test, uuid,
+      { reportResultSuccessCondition:
+          `browserSignals.reportingTimeout === undefined`,
+        reportResult:
+          `sendReportTo('${createSellerReportURL(uuid)}');`,
+        reportWinSuccessCondition:
+          'browserSignals.reportingTimeout === 100',
+        reportWin:
+          `sendReportTo('${createBidderReportURL(uuid)}');` },
+      // expectedReportURLs:
+      [createSellerReportURL(uuid), createBidderReportURL(uuid)],
+      // renderURLOverride
+      null,
+      // auctionConfigOverrides
+      {reportingTimeout: 100});
+}, 'browserSignals.reportingTimeout with custom value from auction config.');
+
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  await runReportTest(
+      test, uuid,
+      { reportResultSuccessCondition:
+          `browserSignals.reportingTimeout === undefined`,
+        reportResult:
+          `sendReportTo('${createSellerReportURL(uuid)}');`,
+        reportWinSuccessCondition:
+          'browserSignals.reportingTimeout === 5000',
+        reportWin:
+          `sendReportTo('${createBidderReportURL(uuid)}');` },
+      // expectedReportURLs:
+      [createSellerReportURL(uuid), createBidderReportURL(uuid)],
+      // renderURLOverride
+      null,
+      // auctionConfigOverrides
+      {reportingTimeout: 1234567890});
+}, 'browserSignals.reportingTimeout above the cap value.');
+
+subsetTest(promise_test, async test => {
+  await runReportArgumentValidationTest(
+    test,
+    // reportResultSuccessCondition:
+    `browserSignals.reportingTimeout === undefined`,
+    // reportWinSuccessCondition:
+    `browserSignals.reportingTimeout === 50`
+  );
+}, 'browserSignals.reportingTimeout default value.');
diff --git a/testing/web-platform/tests/fledge/tentative/resources/additional-bids.py b/testing/web-platform/tests/fledge/tentative/resources/additional-bids.py
index 060606b41d..721909a045 100644
--- a/testing/web-platform/tests/fledge/tentative/resources/additional-bids.py
+++ b/testing/web-platform/tests/fledge/tentative/resources/additional-bids.py
@@ -13,6 +13,7 @@ with a value of b"?1"; this entrypoint otherwise returns a 400 response.
 import json
 import base64
 
+import fledge.tentative.resources.ed25519 as ed25519
 import fledge.tentative.resources.fledge_http_server_util as fledge_http_server_util
 
 
@@ -20,6 +21,57 @@ class BadRequestError(Exception):
   pass
 
 
+def _generate_signature(message, base64_encoded_secret_key):
+  """Returns a signature entry for a signed additional bid.
+
+  Args:
+    base64_encoded_secret_key: base64-encoded Ed25519 key with which to sign
+        the message. From this secret key, the public key can be deduced, which
+        becomes part of the signature entry.
+    message: The additional bid text (or other text if generating an invalid
+        signature) to sign.
+  """
+  secret_key = base64.b64decode(base64_encoded_secret_key.encode("utf-8"))
+  public_key = ed25519.publickey_unsafe(secret_key)
+  signature = ed25519.signature_unsafe(
+      message.encode("utf-8"), secret_key, public_key)
+  return {
+      "key": base64.b64encode(public_key).decode("utf-8"),
+      "signature": base64.b64encode(signature).decode("utf-8")
+  }
+
+
+def _sign_additional_bid(additional_bid_string,
+                         secret_keys_for_valid_signatures,
+                         secret_keys_for_invalid_signatures):
+  """Returns a signed additional bid given an additional bid and secret keys.
+
+  Args:
+    additional_bid_string: string representation of the additional bid
+    secret_keys_for_valid_signatures: a list of strings, each a base64-encoded
+        Ed25519 secret key with which to sign the additional bid
+    secret_keys_for_invalid_signatures: a list of strings, each a base64-encoded
+        Ed25519 secret key with which to incorrectly sign the additional bid
+  """
+  signatures = []
+  signatures.extend(
+      _generate_signature(additional_bid_string, secret_key)
+      for secret_key in secret_keys_for_valid_signatures)
+
+  # For invalid signatures, we use the correct secret key to sign a different
+  # message - the additional bid prepended by 'invalid' - so that the signature
+  # is a structually valid signature but can't be used to verify the additional
+  # bid.
+  signatures.extend(
+      _generate_signature("invalid" + additional_bid_string, secret_key)
+       for secret_key in secret_keys_for_invalid_signatures)
+
+  return json.dumps({
+    "bid": additional_bid_string,
+    "signatures": signatures
+  })
+
+
 def main(request, response):
   try:
     if fledge_http_server_util.handle_cors_headers_and_preflight(request, response):
@@ -34,14 +86,16 @@ def main(request, response):
     if not additional_bids:
       raise BadRequestError("Missing 'additionalBids' parameter")
     for additional_bid in json.loads(additional_bids):
-      additional_bid_string = json.dumps(additional_bid)
+      # Each additional bid may have associated testMetadata. Remove this from
+      # the additional bid and use it to adjust the behavior of this handler.
+      test_metadata = additional_bid.pop("testMetadata", {})
       auction_nonce = additional_bid.get("auctionNonce", None)
       if not auction_nonce:
         raise BadRequestError("Additional bid missing required 'auctionNonce' field")
-      signed_additional_bid = json.dumps({
-        "bid": additional_bid_string,
-        "signatures": []
-      })
+      signed_additional_bid = _sign_additional_bid(
+          json.dumps(additional_bid),
+          test_metadata.get("secretKeysForValidSignatures", []),
+          test_metadata.get("secretKeysForInvalidSignatures", []))
       additional_bid_header_value = (auction_nonce.encode("utf-8") + b":" +
                                      base64.b64encode(signed_additional_bid.encode("utf-8")))
       response.headers.append(b"Ad-Auction-Additional-Bid", additional_bid_header_value)
diff --git a/testing/web-platform/tests/fledge/tentative/resources/ed25519.py b/testing/web-platform/tests/fledge/tentative/resources/ed25519.py
new file mode 100644
index 0000000000..53e548ab8e
--- /dev/null
+++ b/testing/web-platform/tests/fledge/tentative/resources/ed25519.py
@@ -0,0 +1,289 @@
+# ed25519.py - Optimized version of the reference implementation of Ed25519
+#
+# Written in 2011? by Daniel J. Bernstein <djb@cr.yp.to>
+#            2013 by Donald Stufft <donald@stufft.io>
+#            2013 by Alex Gaynor <alex.gaynor@gmail.com>
+#            2013 by Greg Price <price@mit.edu>
+#
+# To the extent possible under law, the author(s) have dedicated all copyright
+# and related and neighboring rights to this software to the public domain
+# worldwide. This software is distributed without any warranty.
+#
+# You should have received a copy of the CC0 Public Domain Dedication along
+# with this software. If not, see
+# <http://creativecommons.org/publicdomain/zero/1.0/>.
+#
+# Downloaded from https://raw.githubusercontent.com/pyca/ed25519/main/ed25519.py
+# on April 1, 2024.
+
+"""
+NB: This code is not safe for use with secret keys or secret data.
+The only safe use of this code is for verifying signatures on public messages.
+
+Functions for computing the public key of a secret key and for signing
+a message are included, namely publickey_unsafe and signature_unsafe,
+for testing purposes only.
+
+The root of the problem is that Python's long-integer arithmetic is
+not designed for use in cryptography.  Specifically, it may take more
+or less time to execute an operation depending on the values of the
+inputs, and its memory access patterns may also depend on the inputs.
+This opens it to timing and cache side-channel attacks which can
+disclose data to an attacker.  We rely on Python's long-integer
+arithmetic, so we cannot handle secrets without risking their disclosure.
+"""
+
+import hashlib
+
+
+__version__ = "1.0.dev0"
+
+
+b = 256
+q = 2**255 - 19
+l = 2**252 + 27742317777372353535851937790883648493
+
+
+def H(m):
+    return hashlib.sha512(m).digest()
+
+
+def pow2(x, p):
+    """== pow(x, 2**p, q)"""
+    while p > 0:
+        x = x * x % q
+        p -= 1
+    return x
+
+
+def inv(z):
+    r"""$= z^{-1} \mod q$, for z != 0"""
+    # Adapted from curve25519_athlon.c in djb's Curve25519.
+    z2 = z * z % q  # 2
+    z9 = pow2(z2, 2) * z % q  # 9
+    z11 = z9 * z2 % q  # 11
+    z2_5_0 = (z11 * z11) % q * z9 % q  # 31 == 2^5 - 2^0
+    z2_10_0 = pow2(z2_5_0, 5) * z2_5_0 % q  # 2^10 - 2^0
+    z2_20_0 = pow2(z2_10_0, 10) * z2_10_0 % q  # ...
+    z2_40_0 = pow2(z2_20_0, 20) * z2_20_0 % q
+    z2_50_0 = pow2(z2_40_0, 10) * z2_10_0 % q
+    z2_100_0 = pow2(z2_50_0, 50) * z2_50_0 % q
+    z2_200_0 = pow2(z2_100_0, 100) * z2_100_0 % q
+    z2_250_0 = pow2(z2_200_0, 50) * z2_50_0 % q  # 2^250 - 2^0
+    return pow2(z2_250_0, 5) * z11 % q  # 2^255 - 2^5 + 11 = q - 2
+
+
+d = -121665 * inv(121666) % q
+I = pow(2, (q - 1) // 4, q)
+
+
+def xrecover(y):
+    xx = (y * y - 1) * inv(d * y * y + 1)
+    x = pow(xx, (q + 3) // 8, q)
+
+    if (x * x - xx) % q != 0:
+        x = (x * I) % q
+
+    if x % 2 != 0:
+        x = q - x
+
+    return x
+
+
+By = 4 * inv(5)
+Bx = xrecover(By)
+B = (Bx % q, By % q, 1, (Bx * By) % q)
+ident = (0, 1, 1, 0)
+
+
+def edwards_add(P, Q):
+    # This is formula sequence 'addition-add-2008-hwcd-3' from
+    # http://www.hyperelliptic.org/EFD/g1p/auto-twisted-extended-1.html
+    (x1, y1, z1, t1) = P
+    (x2, y2, z2, t2) = Q
+
+    a = (y1 - x1) * (y2 - x2) % q
+    b = (y1 + x1) * (y2 + x2) % q
+    c = t1 * 2 * d * t2 % q
+    dd = z1 * 2 * z2 % q
+    e = b - a
+    f = dd - c
+    g = dd + c
+    h = b + a
+    x3 = e * f
+    y3 = g * h
+    t3 = e * h
+    z3 = f * g
+
+    return (x3 % q, y3 % q, z3 % q, t3 % q)
+
+
+def edwards_double(P):
+    # This is formula sequence 'dbl-2008-hwcd' from
+    # http://www.hyperelliptic.org/EFD/g1p/auto-twisted-extended-1.html
+    (x1, y1, z1, t1) = P
+
+    a = x1 * x1 % q
+    b = y1 * y1 % q
+    c = 2 * z1 * z1 % q
+    # dd = -a
+    e = ((x1 + y1) * (x1 + y1) - a - b) % q
+    g = -a + b  # dd + b
+    f = g - c
+    h = -a - b  # dd - b
+    x3 = e * f
+    y3 = g * h
+    t3 = e * h
+    z3 = f * g
+
+    return (x3 % q, y3 % q, z3 % q, t3 % q)
+
+
+def scalarmult(P, e):
+    if e == 0:
+        return ident
+    Q = scalarmult(P, e // 2)
+    Q = edwards_double(Q)
+    if e & 1:
+        Q = edwards_add(Q, P)
+    return Q
+
+
+# Bpow[i] == scalarmult(B, 2**i)
+Bpow = []
+
+
+def make_Bpow():
+    P = B
+    for i in range(253):
+        Bpow.append(P)
+        P = edwards_double(P)
+
+
+make_Bpow()
+
+
+def scalarmult_B(e):
+    """
+    Implements scalarmult(B, e) more efficiently.
+    """
+    # scalarmult(B, l) is the identity
+    e = e % l
+    P = ident
+    for i in range(253):
+        if e & 1:
+            P = edwards_add(P, Bpow[i])
+        e = e // 2
+    assert e == 0, e
+    return P
+
+
+def encodeint(y):
+    bits = [(y >> i) & 1 for i in range(b)]
+    return bytes(
+        [sum([bits[i * 8 + j] << j for j in range(8)]) for i in range(b // 8)]
+    )
+
+
+def encodepoint(P):
+    (x, y, z, t) = P
+    zi = inv(z)
+    x = (x * zi) % q
+    y = (y * zi) % q
+    bits = [(y >> i) & 1 for i in range(b - 1)] + [x & 1]
+    return bytes(
+        [sum([bits[i * 8 + j] << j for j in range(8)]) for i in range(b // 8)]
+    )
+
+
+def bit(h, i):
+    return (h[i // 8] >> (i % 8)) & 1
+
+
+def publickey_unsafe(sk):
+    """
+    Not safe to use with secret keys or secret data.
+
+    See module docstring.  This function should be used for testing only.
+    """
+    h = H(sk)
+    a = 2 ** (b - 2) + sum(2**i * bit(h, i) for i in range(3, b - 2))
+    A = scalarmult_B(a)
+    return encodepoint(A)
+
+
+def Hint(m):
+    h = H(m)
+    return sum(2**i * bit(h, i) for i in range(2 * b))
+
+
+def signature_unsafe(m, sk, pk):
+    """
+    Not safe to use with secret keys or secret data.
+
+    See module docstring.  This function should be used for testing only.
+    """
+    h = H(sk)
+    a = 2 ** (b - 2) + sum(2**i * bit(h, i) for i in range(3, b - 2))
+    r = Hint(bytes([h[j] for j in range(b // 8, b // 4)]) + m)
+    R = scalarmult_B(r)
+    S = (r + Hint(encodepoint(R) + pk + m) * a) % l
+    return encodepoint(R) + encodeint(S)
+
+
+def isoncurve(P):
+    (x, y, z, t) = P
+    return (
+        z % q != 0
+        and x * y % q == z * t % q
+        and (y * y - x * x - z * z - d * t * t) % q == 0
+    )
+
+
+def decodeint(s):
+    return sum(2**i * bit(s, i) for i in range(0, b))
+
+
+def decodepoint(s):
+    y = sum(2**i * bit(s, i) for i in range(0, b - 1))
+    x = xrecover(y)
+    if x & 1 != bit(s, b - 1):
+        x = q - x
+    P = (x, y, 1, (x * y) % q)
+    if not isoncurve(P):
+        raise ValueError("decoding point that is not on curve")
+    return P
+
+
+class SignatureMismatch(Exception):
+    pass
+
+
+def checkvalid(s, m, pk):
+    """
+    Not safe to use when any argument is secret.
+
+    See module docstring.  This function should be used only for
+    verifying public signatures of public messages.
+    """
+    if len(s) != b // 4:
+        raise ValueError("signature length is wrong")
+
+    if len(pk) != b // 8:
+        raise ValueError("public-key length is wrong")
+
+    R = decodepoint(s[: b // 8])
+    A = decodepoint(pk)
+    S = decodeint(s[b // 8 : b // 4])
+    h = Hint(encodepoint(R) + pk + m)
+
+    (x1, y1, z1, t1) = P = scalarmult_B(S)
+    (x2, y2, z2, t2) = Q = edwards_add(R, scalarmult(A, h))
+
+    if (
+        not isoncurve(P)
+        or not isoncurve(Q)
+        or (x1 * z2 - x2 * z1) % q != 0
+        or (y1 * z2 - y2 * z1) % q != 0
+    ):
+        raise SignatureMismatch("signature does not pass verification")
diff --git a/testing/web-platform/tests/fledge/tentative/resources/fledge-util.sub.js b/testing/web-platform/tests/fledge/tentative/resources/fledge-util.sub.js
index 5819357e29..7be02e34ff 100644
--- a/testing/web-platform/tests/fledge/tentative/resources/fledge-util.sub.js
+++ b/testing/web-platform/tests/fledge/tentative/resources/fledge-util.sub.js
@@ -177,7 +177,7 @@ async function waitForObservedRequestsIgnoreDebugOnlyReports(
 function createBiddingScriptURL(params = {}) {
   let origin = params.origin ? params.origin : new URL(BASE_URL).origin;
   let url = new URL(`${origin}${RESOURCE_PATH}bidding-logic.sub.py`);
-  // These checks use "==" to ignore null and not provided arguments, while
+  // These checks use "!=" to ignore null and not provided arguments, while
   // treating '' as a valid argument.
   if (params.generateBid != null)
     url.searchParams.append('generateBid', params.generateBid);
@@ -213,7 +213,7 @@ function createDecisionScriptURL(uuid, params = {}) {
   let origin = params.origin ? params.origin : new URL(BASE_URL).origin;
   let url = new URL(`${origin}${RESOURCE_PATH}decision-logic.sub.py`);
   url.searchParams.append('uuid', uuid);
-  // These checks use "==" to ignore null and not provided arguments, while
+  // These checks use "!=" to ignore null and not provided arguments, while
   // treating '' as a valid argument.
   if (params.scoreAd != null)
     url.searchParams.append('scoreAd', params.scoreAd);
@@ -230,8 +230,8 @@ function createDecisionScriptURL(uuid, params = {}) {
 // be last.  "signalsParams" also has no effect, but is used by
 // trusted-scoring-signals.py to affect the response.
 function createRenderURL(uuid, script, signalsParams, origin) {
-  // These checks use "==" to ignore null and not provided arguments, while
-  // treating '' as a valid argument.
+  // These checks use "==" and "!=" to ignore null and not provided
+  // arguments, while treating '' as a valid argument.
   if (origin == null)
     origin = new URL(BASE_URL).origin;
   let url = new URL(`${origin}${RESOURCE_PATH}fenced-frame.sub.py`);
@@ -260,6 +260,15 @@ function createInterestGroupForOrigin(uuid, origin,
   };
 }
 
+// Waits for the join command to complete. Adds cleanup command to `test` to
+// leave the interest group when the test completes.
+async function joinInterestGroupWithoutDefaults(test, interestGroup,
+                                                durationSeconds = 60) {
+  await navigator.joinAdInterestGroup(interestGroup, durationSeconds);
+  test.add_cleanup(
+    async () => { await navigator.leaveAdInterestGroup(interestGroup); });
+}
+
 // Joins an interest group that, by default, is owned by the current frame's
 // origin, is named DEFAULT_INTEREST_GROUP_NAME, has a bidding script that
 // issues a bid of 9 with a renderURL of "https://not.checked.test/${uuid}",
@@ -271,12 +280,33 @@ function createInterestGroupForOrigin(uuid, origin,
 // interest group.
 async function joinInterestGroup(test, uuid, interestGroupOverrides = {},
                                  durationSeconds = 60) {
-  let interestGroup = createInterestGroupForOrigin(uuid, window.location.origin,
-                                                   interestGroupOverrides);
-
-  await navigator.joinAdInterestGroup(interestGroup, durationSeconds);
-  test.add_cleanup(
-    async () => { await navigator.leaveAdInterestGroup(interestGroup) });
+  await joinInterestGroupWithoutDefaults(
+      test, createInterestGroupForOrigin(
+          uuid, window.location.origin, interestGroupOverrides),
+      durationSeconds);
+}
+
+// Joins a negative interest group with the specified owner, name, and
+// additionalBidKey. Because these are the only valid fields for a negative
+// interest groups, this function doesn't expose an 'overrides' parameter.
+// Adds cleanup command to `test` to leave the interest group when the test
+// completes.
+async function joinNegativeInterestGroup(
+    test, owner, name, additionalBidKey) {
+  let interestGroup = {
+    owner: owner,
+    name: name,
+    additionalBidKey: additionalBidKey
+  };
+  if (owner !== window.location.origin) {
+    let iframe = await createIframe(test, owner, 'join-ad-interest-group');
+    await runInFrame(
+      test, iframe,
+      `await joinInterestGroupWithoutDefaults(` +
+          `test_instance, ${JSON.stringify(interestGroup)})`);
+  } else {
+    await joinInterestGroupWithoutDefaults(test_instance, interestGroup);
+  }
 }
 
 // Similar to joinInterestGroup, but leaves the interest group instead.
@@ -487,6 +517,17 @@ async function runReportTest(test, uuid, codeToInsert, expectedReportURLs,
   await waitForObservedRequests(uuid, expectedReportURLs);
 }
 
+// Helper function for running a standard test of the additional bid and
+// negative targeting features. This helper verifies that the auction produces a
+// winner. It takes the following arguments:
+// - test/uuid: the test object and uuid from the test case (see generateUuid)
+// - buyers: array of strings, each a domain for a buyer participating in this
+//       auction
+// - actionNonce: string, the auction nonce for this auction, typically
+//       retrieved from a prior call to navigator.createAuctionNonce
+// - highestScoringOtherBid: the amount of the second-highest bid,
+//       or zero if there's no second-highest bid
+// - winningAdditionalBidId: the label of the winning bid
 async function runAdditionalBidTest(test, uuid, buyers, auctionNonce,
                                     additionalBidsPromise,
                                     highestScoringOtherBid,
@@ -516,7 +557,7 @@ async function runInFrame(test, child_window, script, param) {
 
   let promise = new Promise(function(resolve, reject) {
     function WaitForMessage(event) {
-      if (event.data.messageUuid != messageUuid)
+      if (event.data.messageUuid !== messageUuid)
         return;
       receivedResponse = event.data;
       if (event.data.result === 'success') {
@@ -548,7 +589,7 @@ async function createFrame(test, origin, is_iframe = true, permissions = null) {
       `${origin}${RESOURCE_PATH}subordinate-frame.sub.html?uuid=${frameUuid}`;
   let promise = new Promise(function(resolve, reject) {
     function WaitForMessage(event) {
-      if (event.data.messageUuid != frameUuid)
+      if (event.data.messageUuid !== frameUuid)
         return;
       if (event.data.result === 'load complete') {
         resolve();
@@ -662,79 +703,130 @@ function directFromSellerSignalsValidatorCode(uuid, expectedSellerSignals,
   return {
     // Seller worklets
     scoreAd:
-      `if (directFromSellerSignals === null ||
+      `if (directFromSellerSignals == null ||
            directFromSellerSignals.sellerSignals !== ${expectedSellerSignals} ||
            directFromSellerSignals.auctionSignals !== ${expectedAuctionSignals} ||
-           Object.keys(directFromSellerSignals).length != 2) {
+           Object.keys(directFromSellerSignals).length !== 2) {
               throw 'Failed to get expected directFromSellerSignals in scoreAd(): ' +
                 JSON.stringify(directFromSellerSignals);
           }`,
     reportResultSuccessCondition:
-      `directFromSellerSignals !== null &&
+      `directFromSellerSignals != null &&
            directFromSellerSignals.sellerSignals === ${expectedSellerSignals} &&
            directFromSellerSignals.auctionSignals === ${expectedAuctionSignals} &&
-           Object.keys(directFromSellerSignals).length == 2`,
+           Object.keys(directFromSellerSignals).length === 2`,
     reportResult:
       `sendReportTo("${createSellerReportURL(uuid)}");`,
 
     // Bidder worklets
     generateBid:
-      `if (directFromSellerSignals === null ||
+      `if (directFromSellerSignals == null ||
            directFromSellerSignals.perBuyerSignals !== ${expectedPerBuyerSignals} ||
            directFromSellerSignals.auctionSignals !== ${expectedAuctionSignals} ||
-           Object.keys(directFromSellerSignals).length != 2) {
+           Object.keys(directFromSellerSignals).length !== 2) {
               throw 'Failed to get expected directFromSellerSignals in generateBid(): ' +
                 JSON.stringify(directFromSellerSignals);
         }`,
     reportWinSuccessCondition:
-      `directFromSellerSignals !== null &&
+      `directFromSellerSignals != null &&
            directFromSellerSignals.perBuyerSignals === ${expectedPerBuyerSignals} &&
            directFromSellerSignals.auctionSignals === ${expectedAuctionSignals} &&
-           Object.keys(directFromSellerSignals).length == 2`,
+           Object.keys(directFromSellerSignals).length === 2`,
     reportWin:
       `sendReportTo("${createBidderReportURL(uuid)}");`,
   };
 }
 
-// Creates an additional bid with the given parameters. This additional bid
-// specifies a biddingLogicURL that provides an implementation of
-// reportAdditionalBidWin that triggers a sendReportTo() to the bidder report
-// URL of the winning additional bid. Additional bids are described in more
-// detail at
-// https://github.com/WICG/turtledove/blob/main/FLEDGE.md#6-additional-bids.
-function createAdditionalBid(uuid, auctionNonce, seller, buyer, interestGroupName, bidAmount,
-                             additionalBidOverrides = {}) {
-  return {
-    interestGroup: {
-      name: interestGroupName,
-      biddingLogicURL: createBiddingScriptURL(
-        {
-          origin: buyer,
-          reportAdditionalBidWin: `sendReportTo("${createBidderReportURL(uuid, interestGroupName)}");`
-        }),
-      owner: buyer
-    },
-    bid: {
-      ad: ['metadata'],
-      bid: bidAmount,
-      render: createRenderURL(uuid)
-    },
-    auctionNonce: auctionNonce,
-    seller: seller,
-    ...additionalBidOverrides
+let additionalBidHelper = function() {
+  // Creates an additional bid with the given parameters. This additional bid
+  // specifies a biddingLogicURL that provides an implementation of
+  // reportAdditionalBidWin that triggers a sendReportTo() to the bidder report
+  // URL of the winning additional bid. Additional bids are described in more
+  // detail at
+  // https://github.com/WICG/turtledove/blob/main/FLEDGE.md#6-additional-bids.
+  function createAdditionalBid(uuid, auctionNonce, seller, buyer, interestGroupName, bidAmount,
+                               additionalBidOverrides = {}) {
+    return {
+      interestGroup: {
+        name: interestGroupName,
+        biddingLogicURL: createBiddingScriptURL(
+          {
+            origin: buyer,
+            reportAdditionalBidWin: `sendReportTo("${createBidderReportURL(uuid, interestGroupName)}");`
+          }),
+        owner: buyer
+      },
+      bid: {
+        ad: ['metadata'],
+        bid: bidAmount,
+        render: createRenderURL(uuid)
+      },
+      auctionNonce: auctionNonce,
+      seller: seller,
+      ...additionalBidOverrides
+    };
   }
-}
 
-// Fetch some number of additional bid from a seller and verify that the
-// 'Ad-Auction-Additional-Bid' header is not visible in this JavaScript context.
-// The `additionalBids` parameter is a list of additional bids.
-async function fetchAdditionalBids(seller, additionalBids) {
-  const url = new URL(`${seller}${RESOURCE_PATH}additional-bids.py`);
-  url.searchParams.append('additionalBids', JSON.stringify(additionalBids));
-  const response = await fetch(url.href, {adAuctionHeaders: true});
+  // Gets the testMetadata for an additional bid, initializing it if needed.
+  function getAndMaybeInitializeTestMetadata(additionalBid) {
+    if (additionalBid.testMetadata === undefined) {
+      additionalBid.testMetadata = {};
+    }
+    return additionalBid.testMetadata;
+  }
 
-  assert_equals(response.status, 200, 'Failed to fetch additional bid: ' + await response.text());
-  assert_false(
-      response.headers.has('Ad-Auction-Additional-Bid'),
-      'Header "Ad-Auction-Additional-Bid" should not be available in JavaScript context.');
-}
+  // Tells the additional bid endpoint to correctly sign the additional bid with
+  // the given secret keys before returning that as a signed additional bid.
+  function signWithSecretKeys(additionalBid, secretKeys) {
+    getAndMaybeInitializeTestMetadata(additionalBid).
+        secretKeysForValidSignatures = secretKeys;
+  }
+
+  // Tells the additional bid endpoint to incorrectly sign the additional bid with
+  // the given secret keys before returning that as a signed additional bid. This
+  // is used for testing the behavior when the auction encounters an invalid
+  // signature.
+  function incorrectlySignWithSecretKeys(additionalBid, secretKeys) {
+    getAndMaybeInitializeTestMetadata(additionalBid).
+        secretKeysForInvalidSignatures = secretKeys;
+  }
+
+  // Adds a single negative interest group to an additional bid, as described at:
+  // https://github.com/WICG/turtledove/blob/main/FLEDGE.md#622-how-additional-bids-specify-their-negative-interest-groups
+  function addNegativeInterestGroup(additionalBid, negativeInterestGroup) {
+    additionalBid["negativeInterestGroup"] = negativeInterestGroup;
+  }
+
+  // Adds multiple negative interest groups to an additional bid, as described at:
+  // https://github.com/WICG/turtledove/blob/main/FLEDGE.md#622-how-additional-bids-specify-their-negative-interest-groups
+  function addNegativeInterestGroups(additionalBid, negativeInterestGroups,
+                                     joiningOrigin) {
+    additionalBid["negativeInterestGroups"] = {
+      joiningOrigin: joiningOrigin,
+      interestGroupNames: negativeInterestGroups
+    };
+  }
+
+  // Fetch some number of additional bid from a seller and verify that the
+  // 'Ad-Auction-Additional-Bid' header is not visible in this JavaScript context.
+  // The `additionalBids` parameter is a list of additional bids.
+  async function fetchAdditionalBids(seller, additionalBids) {
+    const url = new URL(`${seller}${RESOURCE_PATH}additional-bids.py`);
+    url.searchParams.append('additionalBids', JSON.stringify(additionalBids));
+    const response = await fetch(url.href, {adAuctionHeaders: true});
+
+    assert_equals(response.status, 200, 'Failed to fetch additional bid: ' + await response.text());
+    assert_false(
+        response.headers.has('Ad-Auction-Additional-Bid'),
+        'Header "Ad-Auction-Additional-Bid" should not be available in JavaScript context.');
+  }
+
+  return {
+    createAdditionalBid: createAdditionalBid,
+    signWithSecretKeys: signWithSecretKeys,
+    incorrectlySignWithSecretKeys: incorrectlySignWithSecretKeys,
+    addNegativeInterestGroup: addNegativeInterestGroup,
+    addNegativeInterestGroups: addNegativeInterestGroups,
+    fetchAdditionalBids: fetchAdditionalBids
+  };
+}();
diff --git a/testing/web-platform/tests/fledge/tentative/resources/trusted-bidding-signals.py b/testing/web-platform/tests/fledge/tentative/resources/trusted-bidding-signals.py
index 45bede2c45..f9ca9031f1 100644
--- a/testing/web-platform/tests/fledge/tentative/resources/trusted-bidding-signals.py
+++ b/testing/web-platform/tests/fledge/tentative/resources/trusted-bidding-signals.py
@@ -110,6 +110,8 @@ def main(request, response):
                 value = request.GET.first(b"slotSize", b"not-found").decode("ASCII")
             elif key == "allSlotsRequestedSizes":
                 value = request.GET.first(b"allSlotsRequestedSizes", b"not-found").decode("ASCII")
+            elif key == "url":
+                value = request.url
             responseBody["keys"][key] = value
 
     if "data-version" in interestGroupNames:
diff --git a/testing/web-platform/tests/fledge/tentative/resources/trusted-scoring-signals.py b/testing/web-platform/tests/fledge/tentative/resources/trusted-scoring-signals.py
index eccef5e762..ce53e76295 100644
--- a/testing/web-platform/tests/fledge/tentative/resources/trusted-scoring-signals.py
+++ b/testing/web-platform/tests/fledge/tentative/resources/trusted-scoring-signals.py
@@ -122,6 +122,8 @@ def main(request, response):
                         value = request.GET.first(b"hostname", b"not-found").decode("ASCII")
                     elif signalsParam == "headers":
                         value = fledge_http_server_util.headers_to_ascii(request.headers)
+                    elif signalsParam == "url":
+                        value = request.url
             if addValue:
                 if urlList["type"] not in responseBody:
                     responseBody[urlList["type"]] = {}
diff --git a/testing/web-platform/tests/fledge/tentative/resources/worklet-helpers.js b/testing/web-platform/tests/fledge/tentative/resources/worklet-helpers.js
index 2147a026ae..0bac1b99a9 100644
--- a/testing/web-platform/tests/fledge/tentative/resources/worklet-helpers.js
+++ b/testing/web-platform/tests/fledge/tentative/resources/worklet-helpers.js
@@ -11,10 +11,10 @@ function deepEquals(a, b) {
     return a === b;
 
   let aKeys = Object.keys(a);
-  if (aKeys.length != Object.keys(b).length)
+  if (aKeys.length !== Object.keys(b).length)
     return false;
   for (let key of aKeys) {
-    if (a.hasOwnProperty(key) != b.hasOwnProperty(key) ||
+    if (a.hasOwnProperty(key) !== b.hasOwnProperty(key) ||
         !deepEquals(a[key], b[key])) {
       return false;
     }
diff --git a/testing/web-platform/tests/fledge/tentative/tie.https.window.js b/testing/web-platform/tests/fledge/tentative/tie.https.window.js
index 48d6e95e5c..c87d10f201 100644
--- a/testing/web-platform/tests/fledge/tentative/tie.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/tie.https.window.js
@@ -98,7 +98,7 @@ promise_test(async test => {
   auctionConfigOverrides.decisionLogicURL =
       createDecisionScriptURL(
         uuid,
-        {scoreAd: `if (browserSignals.renderURL == "${winningAdURL}")
+        {scoreAd: `if (browserSignals.renderURL === "${winningAdURL}")
                      return 0;`});
 
   // Add an abort controller, so can cancel extra auctions.
diff --git a/testing/web-platform/tests/fledge/tentative/trusted-bidding-signals.https.window.js b/testing/web-platform/tests/fledge/tentative/trusted-bidding-signals.https.window.js
index 9799af6ac1..d0b9a82086 100644
--- a/testing/web-platform/tests/fledge/tentative/trusted-bidding-signals.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/trusted-bidding-signals.https.window.js
@@ -16,7 +16,8 @@
 // META: variant=?51-55
 // META: variant=?56-60
 // META: variant=?61-65
-// META: variant=?66-last
+// META: variant=?66-70
+// META: variant=?71-last
 
 "use strict";
 
@@ -785,3 +786,156 @@ subsetTest(promise_test, async test => {
       auctionConfigOverrides,
       uuid);
 }, 'all-slots-requested-sizes trustedBiddingSignalsSlotSizeMode in a component auction');
+
+/////////////////////////////////////////////////////////////////////////////
+// maxTrustedBiddingSignalsURLLength tests
+/////////////////////////////////////////////////////////////////////////////
+
+// Trusted bidding signals can be retrieved when `maxTrustedBiddingSignalsURLLength` is set to 0,
+// which means infinite length limit.
+// In the following three tests, the generated request URL contains approximately 166 characters.
+// The target of the tests is primarily to make sure all the signals are fetched with the full URL.
+subsetTest(promise_test, async test => {
+  const name = 'group';
+  await runTrustedBiddingSignalsTest(
+      test,
+      // Check the URL length is within an approximate range to ensure the URL is not truncated.
+      ` trustedBiddingSignals["interest-group-names"] === '["${name}"]' &&
+        trustedBiddingSignals["url"].length > 150 &&
+        trustedBiddingSignals["url"].length < 180 `,
+      {
+        name: name,
+        trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+        trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+        maxTrustedBiddingSignalsURLLength: 0
+      });
+}, 'Trusted bidding signals request works with a URL length limit set to 0.');
+
+// Trusted bidding signals can be retrieved when `maxTrustedBiddingSignalsURLLength` is set to
+// a non-zero value smaller than the length of the request URL. It also tests that multiple
+// bidding keys from the same interest group will not be separated even the full URL length is
+// larger than the limit.
+subsetTest(promise_test, async test => {
+  const name = 'group';
+  await runTrustedBiddingSignalsTest(
+      test,
+      ` trustedBiddingSignals["interest-group-names"] === '["${name}"]' &&
+        trustedBiddingSignals["url"].length > 150 &&
+        trustedBiddingSignals["url"].length < 180 `,
+      {
+        name: name,
+        trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+        trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+        maxTrustedBiddingSignalsURLLength: 1
+      });
+}, 'Trusted bidding signals request works with a URL length limit smaller than the URL length.');
+
+// Trusted bidding signals can be retrieved when `maxTrustedBiddingSignalsURLLength` is set to
+// a value larger than the length of the request URL.
+subsetTest(promise_test, async test => {
+  const name = 'group';
+  await runTrustedBiddingSignalsTest(
+      test,
+      ` trustedBiddingSignals["interest-group-names"] === '["${name}"]' &&
+        trustedBiddingSignals["url"].length < 180 `,
+      {
+        name: name,
+        trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+        trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+        maxTrustedBiddingSignalsURLLength: 1000
+      });
+}, 'Trusted bidding signals request works with a URL length limit larger than the URL length.');
+
+// Test whether an oversized trusted bidding signals request URL, generated from two interest
+// groups, will be split into two parts when `maxTrustedBiddingSignalsURLLength` is set to a
+// value larger than a single URL length and smaller than the combined URL length. A request
+// URL from a single interest group contains about 188 characters, while a request URL from
+// two interest groups contains about 216 characters. Note that this test can only verifies
+// the fetch status of the winner's trusted bidding signal, which is the second interest
+// group. We consider the request to be split if the URL length check passes for the second
+// interest group.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const name1 = 'extraordinarilyLongNameGroup1';
+  const name2 = 'extraordinarilyLongNameGroup2';
+
+  await Promise.all(
+      [ joinInterestGroup(
+          test, uuid,
+          {
+            name: name1,
+            trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+            trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+            maxTrustedBiddingSignalsURLLength: 200,
+            biddingLogicURL: createBiddingScriptURL(
+                {
+                  // Return 0 as bid to force the second interest group to win. This interest group
+                  // is considered as fetching trusted bidding signals by itself if the winner's
+                  // URL length passes the limit check.
+                  generateBid:
+                    `return { bid: 0, render: interestGroup.ads[0].renderURL };`
+                })
+          }),
+        joinInterestGroup(
+          test, uuid,
+          {
+            name: name2,
+            trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+            trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+            maxTrustedBiddingSignalsURLLength: 200,
+            biddingLogicURL: createBiddingScriptURL(
+                {
+                  generateBid:
+                    `if (trustedBiddingSignals["interest-group-names"] !== '["${name2}"]' ||
+                        trustedBiddingSignals["url"].length > 200) {
+                      throw "unexpected trustedBiddingSignals";
+                    }
+                    return { bid: 10, render: interestGroup.ads[0].renderURL };`})
+          })
+      ]
+  );
+  runBasicFledgeTestExpectingWinner(test, uuid);
+}, 'Trusted bidding signals splits the request if the combined URL length exceeds the limit of regular value.');
+
+// Test whether an oversized trusted bidding signals request URL, generated from two interest
+// groups, will be split into two parts when `maxTrustedBiddingSignalsURLLength` is set to a
+// value smaller than a single URL length.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const name1 = 'extraordinaryLongNameGroup1';
+  const name2 = 'extraordinaryLongNameGroup2';
+
+  await Promise.all(
+      [ joinInterestGroup(
+          test, uuid,
+          {
+            name: name1,
+            trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+            trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+            maxTrustedBiddingSignalsURLLength: 1,
+            biddingLogicURL: createBiddingScriptURL(
+                {
+                  generateBid:
+                    `return { bid: 0, render: interestGroup.ads[0].renderURL };`
+                })
+          }),
+        joinInterestGroup(
+          test, uuid,
+          {
+            name: name2,
+            trustedBiddingSignalsKeys: ['interest-group-names', 'url'],
+            trustedBiddingSignalsURL: TRUSTED_BIDDING_SIGNALS_URL,
+            maxTrustedBiddingSignalsURLLength: 1,
+            biddingLogicURL: createBiddingScriptURL(
+                {
+                  generateBid:
+                    `if (trustedBiddingSignals["interest-group-names"] !== '["${name2}"]' ||
+                        trustedBiddingSignals["url"].length > 200) {
+                      throw "unexpected trustedBiddingSignals";
+                    }
+                    return { bid: 10, render: interestGroup.ads[0].renderURL };`})
+          })
+      ]
+  );
+  runBasicFledgeTestExpectingWinner(test, uuid);
+}, 'Trusted bidding signals splits the request if the combined URL length exceeds the limit of small value.');
\ No newline at end of file
diff --git a/testing/web-platform/tests/fledge/tentative/trusted-scoring-signals.https.window.js b/testing/web-platform/tests/fledge/tentative/trusted-scoring-signals.https.window.js
index 4de5cfc0f3..105b09fb3b 100644
--- a/testing/web-platform/tests/fledge/tentative/trusted-scoring-signals.https.window.js
+++ b/testing/web-platform/tests/fledge/tentative/trusted-scoring-signals.https.window.js
@@ -11,7 +11,8 @@
 // META: variant=?26-30
 // META: variant=?31-35
 // META: variant=?36-40
-// META: variant=?41-last
+// META: variant=?41-45
+// META: variant=?45-last
 
 "use strict";
 
@@ -510,3 +511,151 @@ subsetTest(promise_test, async test => {
       })
     });
 }, 'Component ads trusted scoring signals.');
+
+/////////////////////////////////////////////////////////////////////////////
+// maxTrustedBiddingSignalsURLLength tests
+/////////////////////////////////////////////////////////////////////////////
+
+// Trusted scoring signals can be retrieved when `maxTrustedScoringSignalsURLLength` is set to 0.
+// In the following three tests, the generated request URL contains approximately 294 characters.
+// The target of the tests is primarily to make sure the signals were fetched with the full URL.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const renderURL = createRenderURL(uuid, /*script=*/null, 'url');
+  const interestGroupOverrides = { ads: [{ renderURL: renderURL }] };
+  const auctionConfigOverrides = {
+      trustedScoringSignalsURL: TRUSTED_SCORING_SIGNALS_URL,
+      maxTrustedScoringSignalsURLLength: 0,
+      decisionLogicURL:
+        createDecisionScriptURL(uuid, {
+            // Check the URL length is within an approximate range to ensure the URL is not truncated.
+            scoreAd:
+              `if (trustedScoringSignals.renderURL["${renderURL}"].length < 280 ||
+                  trustedScoringSignals.renderURL["${renderURL}"].length > 300)
+                throw "error";`
+        })
+  };
+
+  await joinGroupAndRunBasicFledgeTestExpectingWinner(
+    test,
+    {
+      uuid: uuid,
+      interestGroupOverrides: interestGroupOverrides,
+      auctionConfigOverrides: auctionConfigOverrides
+    });
+}, 'Trusted scoring signals request works with a URL length limit set to 0.');
+
+// Trusted scoring signals can be retrieved when `maxTrustedScoringSignalsURLLength` is set to
+// a non-zero value smaller than the length of the request URL.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const renderURL = createRenderURL(uuid, /*script=*/null, 'url');
+  const interestGroupOverrides = { ads: [{ renderURL: renderURL }] };
+  const auctionConfigOverrides = {
+      trustedScoringSignalsURL: TRUSTED_SCORING_SIGNALS_URL,
+      maxTrustedScoringSignalsURLLength: 1,
+      decisionLogicURL:
+        createDecisionScriptURL(uuid, {
+            // Check the URL length is within an approximate range to ensure the URL is not truncated.
+            scoreAd:
+              `if (trustedScoringSignals.renderURL["${renderURL}"].length < 280 ||
+                  trustedScoringSignals.renderURL["${renderURL}"].length > 300)
+                throw "error";`
+        })
+  };
+
+  await joinGroupAndRunBasicFledgeTestExpectingWinner(
+      test,
+      {
+        uuid: uuid,
+        interestGroupOverrides: interestGroupOverrides,
+        auctionConfigOverrides: auctionConfigOverrides
+      });
+}, 'Trusted scoring signals request works with a URL length limit smaller than the URL length.');
+
+// Trusted scoring signals can be retrieved when `maxTrustedScoringSignalsURLLength` is set to
+// a value larger than the length of the request URL.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const renderURL = createRenderURL(uuid, /*script=*/null, 'url');
+  const interestGroupOverrides = { ads: [{ renderURL: renderURL }] };
+  const auctionConfigOverrides = {
+      trustedScoringSignalsURL: TRUSTED_SCORING_SIGNALS_URL,
+      maxTrustedScoringSignalsURLLength: 1000,
+      decisionLogicURL:
+        createDecisionScriptURL(uuid, {
+            scoreAd: `if (trustedScoringSignals.renderURL["${renderURL}"].length > 300) throw "error";`
+        })
+  };
+
+  await joinGroupAndRunBasicFledgeTestExpectingWinner(
+      test,
+      {
+        uuid: uuid,
+        interestGroupOverrides: interestGroupOverrides,
+        auctionConfigOverrides: auctionConfigOverrides
+      });
+}, 'Trusted scoring signals request works with a URL length limit larger than the URL length.');
+
+// Test whether an oversized trusted scoring signals request URL, generated from two interest
+// groups, will be split into two parts when `maxTrustedScoringSignalsURLLength` is set to a
+// value larger than a single URL length and smaller than the combined URL length. A request
+// URL from a single interest group contains about 294 characters, while a request URL from
+// two interest groups contains about 466 characters.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const renderURL1 = createRenderURL(uuid, /*script=*/null, 'url,group1');
+  const renderURL2 = createRenderURL(uuid, /*script=*/null, 'url,group2');
+  const auctionConfigOverrides = {
+      trustedScoringSignalsURL: TRUSTED_SCORING_SIGNALS_URL,
+      maxTrustedScoringSignalsURLLength: 300,
+      decisionLogicURL:
+        createDecisionScriptURL(uuid, {
+            // This will make the auction reject `renderURL2`, and if `renderURL1` passes the URL
+            // length check, we consider `renderURL2` is fetched by itself in the trusted scoring
+            // signals request.
+            scoreAd:
+              `if (!trustedScoringSignals.renderURL.has("${renderURL1}") ||
+                  trustedScoringSignals.renderURL.has("${renderURL2}") ||
+                  trustedScoringSignals.renderURL["${renderURL1}"].length > 300) {
+                throw "error";
+              }`
+        })
+  };
+
+  await Promise.all(
+      [ joinInterestGroup(test, uuid, { name: 'group 1', ads: [{ renderURL: renderURL1 }] }),
+        joinInterestGroup(test, uuid, { name: 'group 2', ads: [{ renderURL: renderURL2 }] }) ]
+  );
+
+  runBasicFledgeTestExpectingWinner(test, uuid, auctionConfigOverrides);
+}, 'Trusted scoring signals splits the request if the combined URL length exceeds the limit of regular value.');
+
+// Test whether an oversized trusted scoring signals request URL, generated from two interest
+// groups, will be split into two parts when `maxTrustedScoringSignalsURLLength` is set to a
+// value smaller than a single URL length.
+subsetTest(promise_test, async test => {
+  const uuid = generateUuid(test);
+  const renderURL1 = createRenderURL(uuid, /*script=*/null, 'url,group1');
+  const renderURL2 = createRenderURL(uuid, /*script=*/null, 'url,group2');
+  const auctionConfigOverrides = {
+      trustedScoringSignalsURL: TRUSTED_SCORING_SIGNALS_URL,
+      maxTrustedScoringSignalsURLLength: 1,
+      decisionLogicURL:
+        createDecisionScriptURL(uuid, {
+            scoreAd:
+              `if (!trustedScoringSignals.renderURL.has("${renderURL1}") ||
+                  trustedScoringSignals.renderURL.has("${renderURL2}") ||
+                  trustedScoringSignals.renderURL["${renderURL1}"].length > 300) {
+                throw "error";
+              }`
+        })
+  };
+
+  await Promise.all(
+      [ joinInterestGroup(test, uuid, { name: 'group 1', ads: [{ renderURL: renderURL1 }] }),
+        joinInterestGroup(test, uuid, { name: 'group 2', ads: [{ renderURL: renderURL2 }] }) ]
+  );
+
+  runBasicFledgeTestExpectingWinner(test, uuid, auctionConfigOverrides);
+}, 'Trusted scoring signals splits the request if the combined URL length exceeds the limit of small value.');
\ No newline at end of file