Use region specific prebid bundles

.changeset/fluffy-games-jog.md

@@ -0,0 +1,5 @@
+---
+'@guardian/commercial': minor
+---
+
+Use region specific bundles for Prebid

package.json

@@ -103,7 +103,7 @@
 		"webpack-merge": "^6.0.1"
 	},
 	"dependencies": {
-		"@guardian/prebid.js": "8.52.0-8",
+		"@guardian/prebid.js": "8.52.0-9",
 		"@octokit/core": "^6.1.2",
 		"fastdom": "^1.0.11",
 		"lodash-es": "^4.17.21",

src/experiments/ab-tests.ts

@@ -2,6 +2,7 @@ import type { ABTest } from '@guardian/ab-core';
 import { gpidPrebidAdUnits } from './tests/gpid-prebid';
 import { mpuWhenNoEpic } from './tests/mpu-when-no-epic';
 import { optOutFrequencyCap } from './tests/opt-out-frequency-cap';
+import { regionSpecificPrebid } from './tests/region-specific-prebid';
 
 /**
  * You only need to add tests to this file if the code you are testing is here in
@@ -13,4 +14,5 @@ export const concurrentTests: ABTest[] = [
 	mpuWhenNoEpic,
 	optOutFrequencyCap,
 	gpidPrebidAdUnits,
+	regionSpecificPrebid,
 ];

src/experiments/tests/region-specific-prebid.ts

@@ -0,0 +1,29 @@
+import type { ABTest } from '@guardian/ab-core';
+
+export const regionSpecificPrebid: ABTest = {
+	id: 'RegionSpecificPrebid',
+	author: '@commercial-dev',
+	start: '2024-11-25',
+	expiry: '2024-12-23',
+	audience: 0 / 100,
+	audienceOffset: 0 / 100,
+	audienceCriteria: '',
+	successMeasure: '',
+	description:
+		'Test if splitting the Prebid bundle by region improves performance.',
+	variants: [
+		{
+			id: 'control',
+			test: (): void => {
+				/* no-op */
+			},
+		},
+		{
+			id: 'variant',
+			test: (): void => {
+				/* no-op */
+			},
+		},
+	],
+	canRun: () => true,
+};

src/init/consented/prepare-prebid.spec.ts

@@ -18,6 +18,7 @@ jest.mock('utils/geo-utils', () => ({
 jest.mock('experiments/ab', () => ({
 	isInABTestSynchronous: jest.fn().mockReturnValue(false),
 	isInVariantSynchronous: jest.fn().mockReturnValue(false),
+	isUserInVariant: jest.fn().mockReturnValue(false),
 }));
 
 jest.mock('lib/commercial-features', () => ({
@@ -203,7 +204,6 @@ describe('init', () => {
 		commercialFeatures.adFree = false;
 		mockOnConsent(tcfv2WithConsent);
 		mockGetConsentFor(true);
-		(isInCanada as jest.Mock).mockReturnValueOnce(false);
 
 		await setupPrebid();
 		expect(prebid.initialise).toBeCalled();
@@ -295,6 +295,7 @@ describe('init', () => {
 		commercialFeatures.adFree = false;
 		mockOnConsent(tcfv2WithConsent);
 		mockGetConsentFor(true);
+
 		await setupPrebid();
 		expect(prebid.initialise).toBeCalled();
 	});
@@ -330,6 +331,7 @@ describe('init', () => {
 		commercialFeatures.adFree = false;
 		mockOnConsent(usnatWithConsent);
 		mockGetConsentFor(true);
+
 		await setupPrebid();
 		expect(prebid.initialise).toBeCalled();
 	});
@@ -365,6 +367,7 @@ describe('init', () => {
 		commercialFeatures.adFree = false;
 		mockOnConsent(ausWithConsent);
 		mockGetConsentFor(true);
+
 		await setupPrebid();
 		expect(prebid.initialise).toBeCalled();
 	});

src/init/consented/prepare-prebid.ts

@@ -1,11 +1,13 @@
 import type { ConsentFramework } from '@guardian/libs';
 import { getConsentFor, log, onConsent } from '@guardian/libs';
 import { once } from 'lodash-es';
+import { isUserInVariant } from '../../experiments/ab';
+import { regionSpecificPrebid } from '../../experiments/tests/region-specific-prebid';
 import { commercialFeatures } from '../../lib/commercial-features';
 import { isGoogleProxy } from '../../lib/detect/detect-google-proxy';
 import { prebid } from '../../lib/header-bidding/prebid/prebid';
 import { shouldIncludeOnlyA9 } from '../../lib/header-bidding/utils';
-import { isInCanada } from '../../utils/geo-utils';
+import { isInAuOrNz, isInCanada, isInUk, isInUsa } from '../../utils/geo-utils';
 
 const shouldLoadPrebid = () =>
 	!isGoogleProxy() &&
@@ -16,11 +18,25 @@ const shouldLoadPrebid = () =>
 	!shouldIncludeOnlyA9 &&
 	!isInCanada();
 
+const prebidVersion = () => {
+	if (isUserInVariant(regionSpecificPrebid, 'variant')) {
+		if (isInUk()) {
+			return 'uk';
+		} else if (isInAuOrNz()) {
+			return 'aus-nz';
+		} else if (isInUsa()) {
+			return 'us';
+		}
+		return 'row';
+	}
+	return 'all';
+};
+
 const loadPrebid = async (framework: ConsentFramework): Promise<void> => {
 	if (shouldLoadPrebid()) {
 		await import(
-			// @ts-expect-error -- there’s no types for Prebid.js
-			/* webpackChunkName: "Prebid.js" */ '@guardian/prebid.js/build/dist/prebid'
+			/* webpackChunkName: "Prebid.js" */
+			`@guardian/prebid.js/build/dist/${prebidVersion()}/prebid`
 		);
 		prebid.initialise(window, framework);
 	}

src/lib/header-bidding/prebid/prebid.spec.ts

@@ -24,7 +24,7 @@ const resetPrebid = () => {
 	// @ts-expect-error -- there’s no types for this
 	delete window.pbjsChunk;
 	jest.resetModules();
-	jest.requireActual('@guardian/prebid.js/build/dist/prebid');
+	jest.requireActual('@guardian/prebid.js/build/dist/all/prebid');
 };
 
 describe('initialise', () => {