add force particiaptions to AB test participations

Author: dskamiotis

dotcom-rendering/src/client/abTesting.ts

@@ -1,4 +1,5 @@
 import { getCookie, isUndefined } from '@guardian/libs';
+import { getForcedParticipationsFromUrlFlat } from '../lib/getAbUrlHash';
 
 const AB_COOKIE_NAME = 'gu_client_ab_tests';
 
@@ -37,6 +38,7 @@ const getABTestParticipations = (): ABParticipations => {
 	return {
 		...getClientParticipations(),
 		...window.guardian.config.serverSideABTests,
+		...getForcedParticipationsFromUrlFlat(window.location.hash),
 	};
 };
 

dotcom-rendering/src/lib/getAbUrlHash.ts

@@ -21,3 +21,28 @@ export const getForcedParticipationsFromUrl = (
 
 	return {};
 };
+
+export const getForcedParticipationsFromUrlFlat = (
+	windowHash: string,
+): Record<string, string> => {
+	if (windowHash.startsWith('#ab')) {
+		const tokens = windowHash
+			.replace('#ab-', '')
+			.split(',')
+			.map((token) => token.replace(/^ab-/, ''));
+		return tokens.reduce<Record<string, string>>((obj, token) => {
+			const [testId, variantId] = token.split('=');
+
+			if (testId && variantId) {
+				return {
+					...obj,
+					[testId]: variantId,
+				};
+			}
+
+			return obj;
+		}, {});
+	}
+
+	return {};
+};