Eliminate possibility of race condition when getting participations for new ab testing framework (#14663)

* eliminate possibility of race condition for new ab-testing

* update test

Author: Jakeii

dotcom-rendering/src/client/abTesting.ts

@@ -29,18 +29,22 @@ const getClientParticipations = (): ABParticipations => {
 
 	return {};
 };
-const initABTesting = (): void => {
-	const { serverSideABTests } = window.guardian.config;
 
-	const clientSideABTests = getClientParticipations();
-
-	const participations = {
-		...clientSideABTests,
-		...serverSideABTests,
+/**
+ * Get all AB test participations, client and server side
+ */
+const getABTestParticipations = (): ABParticipations => {
+	return {
+		...getClientParticipations(),
+		...window.guardian.config.serverSideABTests,
 	};
+};
+
+const initWindowABTesting = (): void => {
+	const participations = getABTestParticipations();
 
 	window.guardian.modules.abTests = {
-		getParticipations: () => participations,
+		getParticipations: getABTestParticipations,
 		isUserInTest: (testId: string) => {
 			return !isUndefined(participations[testId]);
 		},
@@ -50,4 +54,4 @@ const initABTesting = (): void => {
 	};
 };
 
-export { initABTesting };
+export { initWindowABTesting, getABTestParticipations };

dotcom-rendering/src/client/main.web.ts

@@ -61,7 +61,7 @@ void (async () => {
 		'abTesting',
 		() =>
 			import(/* webpackMode: 'eager' */ './abTesting').then(
-				({ initABTesting }) => initABTesting(),
+				({ initWindowABTesting }) => initWindowABTesting(),
 			),
 		{ priority: 'critical' },
 	);

dotcom-rendering/src/experiments/lib/beta-ab-tests.test.ts

@@ -7,21 +7,10 @@ jest.mock('@guardian/libs', () => ({
 
 // Mock window.guardian
 const mockGetParticipations = jest.fn();
-const mockWindow = {
-	guardian: {
-		modules: {
-			abTests: {
-				getParticipations: mockGetParticipations,
-			},
-		},
-	},
-};
-
-// Set up window mock
-Object.defineProperty(global, 'window', {
-	value: mockWindow,
-	writable: true,
-});
+
+jest.mock('../../client/abTesting', () => ({
+	getABTestParticipations: () => mockGetParticipations(),
+}));
 
 describe('BetaABTests', () => {
 	let betaABTests: BetaABTests;

dotcom-rendering/src/experiments/lib/beta-ab-tests.ts

@@ -1,4 +1,5 @@
 import { isUndefined } from '@guardian/libs';
+import { getABTestParticipations } from '../../client/abTesting';
 
 export interface BetaABTestAPI {
 	getParticipations: () => ABParticipations;
@@ -55,8 +56,7 @@ export class BetaABTests implements BetaABTestAPI {
 		if (isServer) {
 			this.participations = serverSideABTests;
 		} else {
-			this.participations =
-				window.guardian.modules.abTests?.getParticipations() ?? {};
+			this.participations = getABTestParticipations();
 		}
 	}